There’s a paper (Shepherd et al) on ice loss and sea level rise that has been making the rounds in media (such as this article in Science Recorder, claiming it validates global warming) that is causing some stir, mainly because it has a powerfully written press release combined with a volume of researchers (47 scientists), plus additional never before used together satellite data, because more data and more scientists is always better, right?
Here’s the press release where they claim to have “clear evidence”. A deconstruction follows using NASA JPL’s own internal program documents showing that the “certainty” claimed in Shepherd et al really falls apart for lack of a stable reference for the data.
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From the University of Leeds
Clearest evidence yet of polar ice losses
International satellite experts release definitive record of ice sheet changes
An international team of satellite experts has produced the most accurate assessment of ice losses from Antarctica and Greenland to date, ending 20-years of uncertainty.
In a landmark study, published on 30 November in the journal Science, the researchers show that melting of the Antarctic and Greenland ice sheets has contributed 11.1 millimetres to global sea levels since 1992. This amounts to one fifth of all sea level rise over the survey period.
About two thirds of the ice loss was from Greenland, and the remainder was from Antarctica.
Although the ice sheet losses fall within the range reported by the IPCC in 2007, the spread of the IPCC estimate was so broad that it was not clear whether
Antarctica was growing or shrinking. The new estimates are a vast improvement (more than twice as accurate) thanks to the inclusion of more satellite data, and confirm that both Antarctica and Greenland are losing ice.
The study also shows that the combined rate of ice sheet melting has increased over time and, altogether, Greenland and Antarctica are now losing more than three times as much ice (equivalent to 0.95 mm of sea level rise per year) as they were in the 1990s (equivalent to 0.27 mm of sea level rise per year). The Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE) is a collaboration between 47 researchers from 26 laboratories, and was supported by the European Space Agency (ESA) and the National Aeronautics and Space Administration (NASA).
Led by Professor Andrew Shepherd at the University of Leeds and Dr Erik Ivins at NASA’s Jet Propulsion Laboratory, the study combines observations from 10 different satellite missions to develop the first consistent measurement of polar ice sheet changes.
The researchers were able to reconcile the differences between dozens of earlier ice sheet studies through careful use of matching time periods and survey areas, and by combining measurements collected by different types of satellites.
Professor Shepherd, who coordinated the study, said: “The success of this venture is due to the cooperation of the international scientific community, and due to the provision of precise satellite sensors by our space agencies. Without these efforts, we would not be in a position to tell people with confidence how the
Earth’s ice sheets have changed, and to end the uncertainty that has existed for many years.” The study also found differences in the pace of change at each pole.
Dr Ivins, who also coordinated the project, said: “The rate of ice loss from Greenland has increased almost five-fold since the mid-1990s. In contrast, while the regional changes in Antarctic ice over time are sometimes quite striking, the overall balance has remained fairly constant – at least within the certainty of the satellite measurements we have to hand.”
Commenting on the findings, Professor Richard Alley, a climate scientist at Penn State University who was not involved in the study, said: “This project is a spectacular achievement. The data will support essential testing of predictive models, and will lead to a better understanding of how sea-level change may depend on the human decisions that influence global temperatures.”
‘A reconciled estimate of ice sheet mass balance’ by Prof Shepherd et al is published in Science on 30 November 2012, DOI: 10.1126/science.1228102.
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All well and good, and it looks like a home run for Professor Andrew Shepherd at the University of Leeds and Dr Erik Ivins at NASA’s Jet Propulsion Laboratory and the team of 45 others if you just read the press release. But, let’s look a bit deeper, the paper abstract reads:
A Reconciled Estimate of Ice-Sheet Mass Balance
Abstract
We combined an ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass balance of Earth’s polar ice sheets. We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.
Note the key words here “satellite altimetry, interferometry, and gravimetry data sets” along with the second named author “Dr Ivins, who also coordinated the project…at NASA’s Jet Propulsion Laboratory”
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Hold that thought about the key words, and now read this, excerpted from our previous report: Finally: JPL intends to get a GRASP on accurate sea level and ice measurements
New proposal from NASA JPL admits to “spurious” errors in current satellite based sea level and ice altimetry, calls for new space platform to fix the problem.
This recent internal PowerPoint presentation (obtained from an insider) from NASA JPL touts the new GRASP (Geodetic Reference Antenna in Space) satellite project. I’d say it is more than a bit of a bombshell because the whole purpose of this new mission is to “fix” other mission data that apparently never had a stable enough reference for the measurements being made. This promises to rewrite what we know about sea level rise and acceleration, ice extent and ice volume loss measured from space.
What is most interesting, is the admissions of the current state of space based sea level altimetry in the science goals page of the presentation, as shown in the “Key science goals” slide:
The difference between tide gauge data and space based data is over 100% in the left graph, 1.5 mm/yr versus 3.2mm/yr. Of course those who claim that sea level rise is accelerating accept this data without question, but obviously one of the two data sets (or possibly both) is not representative of reality, and JPL’s GRASP team aims to fix this problem they have identified:
TRF errors readily manifest as spurious sea level rise accelerations
That’s a bucket of cold water reality into the face of the current view of sea level rise. It puts this well-known and often cited graph on Sea Level Rise from the University of Colorado (and the rate of 3.1 mm/yr) into question:
What’s a TRF error? That stands for Terrestrial Reference Frame, which is basically saying that errors in determining the benchmark are messing up the survey. In land based geodesy terms, say if somebody messed with the USGS benchmark elevation data from Mt. Diablo California on a regular basis, and the elevation of that benchmark kept changing in the data set, then all measurements referencing that benchmark would be off as well.
In the case of radio altimetry from space, such measurements are extremely dependent on errors related to how radio signals are propagated through the ionosphere. Things like Faraday rotation, refraction, and other propagation issues can skew the signal during transit, and if not properly corrected for, especially over the long-term, it can introduce a spurious signal in all sorts of data derived from it. In fact, the mission summary shows that it will affect satellite derived data for sea level, ice loss, and ice volume in GRACE gravity measurements:
That list of satellites, TOPEX, JASON 1-3, ICESAT1-2, and GRACE 1-2 pretty much represent all of the satellite data used in the new Shepard et al study released this week A Reconciled Estimate of Ice-Sheet Mass Balance.
In a nutshell, other JPL scientists (Yoaz Bar-Sever, R. Steven Nerem, and the GRASP Team) are saying we don’t have an accurate reference point for the satellites, and therefore the data from these previous satellite missions likely has TRF data uncertainties embedded. They say clearly in their PowerPoint presentation that:
The TRF underlies all Measurement of the Earth
And, most importantly, they call for a new space program, GRASP, to fix the problem.
Without that stable Terrestrial Reference Frame that puts the precision of the baseline satellite measurements well below the noise in the data, meaning all we have are broader uncertain measurements. That’s why the plan is to provide ground based points of reference, something our current satellite systems don’t have:
To help understand the items in the side panels:
GNSS = Global Navigation Satellite System – more here
SLR = Satellite Laser Ranging – more here
DORIS = Doppler Orbitography and Radiopositioning Integrated by Satellite – more here
VLBI = Very Long Baseline Interferometry – more here
Taken together, these systems will improve the accuracy of the TRF, and thus the data. It’s rather amazing that the baseline accuracy didn’t come first, because this now puts all these other space based measurement systems into uncertainty until their TRF issues are resolved, and that’s an inconvenient truth.
We’ll never look at satellite based sea level data or GRACE ice volume data in quite the same way again until this is resolved.
See the JPL PowerPoint here: Poland 2012 – P09 Bar-Sever PR51 (PDF)
Summary:
1. JPL admits that satellite measurement of the Earth has issues because a stable Terrestrial Reference Frame was never established for any of the satellite programs. It’s like setting out to do a terrestrial survey without having an accurate benchmark first. This puts all subsequent data derived with the stable benchmark (the stable TRF) into question.
2. The lack of a stable TRF affects most if not all satellite programs used in this new Shepherd et al paper ‘A reconciled estimate of ice sheet mass balance‘ including ICESAT and GRACE, upon which the paper heavily relies.
3. In searching both the full paper (which I purchased from AAAS) and from the extensive supplementary materials and information (SM-SI available here: Shepherd.SM-SI.pdf ) for Shepherd et al, I find no mention of TRF or “Terrestrial Reference Frame” anywhere. It appears that all 47 authors are unaware of the TRF stability issue, or if they were aware, it was never brought to bear in peer review to test the veracity of the paper and its conclusions from the satellite data. Section 3 of the Shepard et al SM-SI deals with uncertainty, but also makes no mention of the TRF issue.
4. The lack of a stable TRF puts all of the space based geodetic data into question, thus the conclusions of the Shepherd et al paper are essentially worthless at the moment, since there isn’t any good way to remove the TRF error from the data with post processing. If there were, the GRASP team at NASA JPL wouldn’t be calling for a new satellite platform and mission to solve the problem. Obviously, this isn’t an issue they take lightly.
In my opinion, the folks at NASA JPL really should get those two teams talking to one another to get a handle on their data before they make grand announcements saying :
An international team of satellite experts has produced the most accurate assessment of ice losses from Antarctica and Greenland to date, ending 20-years of uncertainty.
A good first step would be to get the GRASP mission funded and then go back and redo Shepherd et al to see if it holds up. Until then, it’s just noisy uncertain data.
UPDATE: Figure 4 in the Shepherd et al paper shows clearly how uncertain the GRACE and other data is. They used a brief bit of Laser Altimetry data, shown in green. Laser Altimetry is more accurate that the radar/microwave based data from the other satellite platforms, and is one of the keystones specified for the proposed GRASP mission to clean up the noisy radar/microwave based data.
Note that the Laser Altimetry data in green is essentially flat across the short period where it is included in all four panels, though there is a slight drop in Greenland, but the period is too short to be meaningful.
The uncertainty is quite clear in Table 1, which has error ranges larger than the data in some cases:
The TRF should have been sorted first but perhaps 30 odd years ago the technology was not there. But hey, stable door and bolted horse comes to mind.
Dude! It needs a fold!
see http://theresilientearth.com/?q=content/new-ice-surveys-finds-slower-ice-sheet-melting
for a critique of this ‘paper’
That’s Shepherd, not Shepard.
I was at the panel discussion where he unveiled this a number of weeks ago.
http://tallbloke.wordpress.com/2012/11/02/jonathan-porrit-repositioning-the-climate-change-debate/
REPLY: Fixed thanks – Anthony
This is how they work!
You have to check everything they claim, and you get just as dissapointed everytime how they fudge the numbers makes cliams out of clean air or from pure data noise. They trade no significant trend eith konsensus instead. But they cant no more get a way with thier tricks becdause we have not only catsched up with them we are in front of them when it comes to facts datat and the science. They are corrupted with the “cause”.
I’ve been waiting all weekend for your take on the Shepherd paper [note correct spelling of author’s name]. My understanding of the significance, though, is that despite the uncertainty with any individual measurement, the combination of multiple sources reveals a common pattern. Sort of like Nate Silver projection the election, we can be pretty confident that the ice is really melting even in the Antarctic. Not implying you are trying to unskew the pols, of course, but not sure if your critique is suggesting that underlying reality is suspect because of uncertainty or if you just want more certainty.
Even if the paper was completely accurate it attributes 11mm of sea level rise over the last 20 years to ice loss according to the BBC coverage. That is 55mm per century. And we know that infrared does not heat the oceans, only sunlight can penetrate deeply enough to make a significant impact on ocean temperature and cause expansion. So surely this renders sea level rise a non-threat due to climate change.
So what? The paper has been printed and it is official and if it is not factual does not matter one bit to the climate warming crowd. They will refer to this often and our politicians will use this sort of thing to obtain more of our hard earned money through some type of carbon scheme. It never ends because of the power and money involved- not the science.
They don’t need to get a handle on the data. The mission was to get this headline regurgitated by the MSM while Doha was still in progress. Mission accomplished. MSNBC, NBC, Washington Post, BBC, CBS, the NYT, the Professor and Mary Ann acted as one to plant this seed in the minds of all low-information voters out there.
Saw an article about this in the loss-making Guardian. Damian Carrington was spinning like crazy.
(http://www.guardian.co.uk/environment/2012/nov/29/greenland-antarctica-4-trillion-tonnes-ice)
So it’s down to shifting goal-posts, that makes sense.
“The Ice Sheet Mass Balance Inter-comparison Exercise (IMBIE)” Oh boy! Another “Desert Storm” for the Climate Military! Sounds better than “General Relativity”, huh? More picking of fly poo out of black pepper. The mass balance comes from managing the crop of 47 scientists who had to cram their ideas into this little conflab. More ideas are better, aren’t they?
The absence of a TRF is interesting…glaringly so…if one considers that the entire climate change ball of wax relies on some arbitrary ‘normal’ sea level/temperature condition in order to define the change from that reference. Please, somebody, answer me this: Who decided that reference point? And if your data is essentially uncalibrated to any geodetic standard, how do you expect me to ‘believe’ any of this? Because that’s what it boils down to here. I am to believe that a gob of scientists wrote a paper in which NONE of the gob paused to consider simple calibration? Uh, WTF?
The full article is showing on the front page instead of the usual excerpt. Intentional?
Isn’t this U. of Leeds paper also undercut by the paper reported in the Nov. 29 WUWT thread, http://wattsupwiththat.com/2012/11/29/more-on-noisy-data-from-grace/ ?
Also, don’t these papers undermine this Leeds paper?
more data and more scientists is always better, right?
I think I’ll defer to Willis’ take on a paper’s validity being inversely proportional to the numbers of authors.
Well, at least the GRASP team is trying to get a grip…
@- “A good first step would be to get the GRASP mission funded and then go back and redo Shepard et al to see if it holds up. Until then, it’s just noisy uncertain data.”
Wrong.
The TRF may have uncertainties and errors but this does not translate into any data derived from it being ‘just’ noisy and uncertain. The magnitude of uncertainty matters, it is not a simple binary all or nothing situation. The error range is well defined and that enables any data that uses TRF to be accurately measured to a certain error range. That does NOT invalidate or refute any and all data from these sources, merely puts a limit on their error range. It is simplistic and egregious to use the residual small uncertainty in the TRF to try and reject all the improvements in the measurements of the exceptional increase in ice melt which are in any case measurede by methods that do not rely on TRF as well.
That provides a constraint on how far in error the TRF might be as the data that depend on it are confirmed by data that does not.
In addition to Anthony’s comments.
The Supplemental to the paper says the Greenland mass balance numbers were calculated using the old Peltier ICE-5G VM2 glacial isostatic model.
http://www.ualberta.ca/~dumberry/geoph440/papers/peltier_areaps04.pdf
The Antarctic mass balance and sea level contribution rates were calculated using the newer more accurate W12A and IJ05-R2 glacial isostatic models which make greater use of actual GPS measurements and better timelines on ice-sheet melt as the ice age was ending (in addition to resulting in lower overall glacier growth in Antarctica during the ice ages).
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-246X.2012.05557.x/abstract;jsessionid=B5BDF07602293FAF9C48F94EDA9FB340.d03t01
http://www.geology.cwu.edu/facstaff/tim/g501/pdf/Ivins%26James2005.pdf
The newer glacial isostatic models cut Antarctica’s mass balance losses in half versus Peltier’s ICE-5G VM2 model. So when applied to Greenland, it is expected that the same trend (50% lower) would result.
This puts the sea level contributions much lower as well. The sea level budget will then be far off what is built into the satellite estimates and the assumptions will have to be lowered.
GRACE seems to be the best we have, but it was soon discovered to have flaws – hence the need for the proposed GRASP mission:
From http://ilrs.gsfc.nasa.gov/docs/GRASP_COSPAR_paper.pdf
GEODETIC REFERENCE ANTENNA IN SPACE (GRASP) – A MISSION TO ENHANCE SPACE-BASED GEODESY
Yoaz Bar-Sever (1), Bruce Haines (1), Willy Bertiger(1), Shailen Desai(1), Sien Wu (1)
(1) Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, U.S.A
It sure sounds complex deriving that TRF:
Anthony, 7th line up from the bottom, There’s an extra “really” and “tow” should be two.
REPLY: Fixed thanks – Anthony
Correct me if I am wrong, but even if in an absolute sense the reference value would be incorrect, then still the SLOPE in the period after 1990 would be the same, isn’t it? In other words, the reference value for the satellite data does not change the conclusion that the rate of sea level increase was higher in recent years.
I worked at JPL for two years when I was in college. They had some good people but like any organization, just one of of 50 people in any room really did the heavy lifting. Its annoying that a place that does really good space based sensing would make a rookie mistake like this.
And this paper made the BBC 10 o’clock news last Thursday and a write-up on the BBC website. Pure coincidence that it was aired by the BBC on the same day the govmunt announced its energy bill.
There is an explanation why this paper came into being. With 47 authors and the volume of satellite data, the Shepherd et al study had been in the works long before mention of the GRASP proposal. Remember, these guys have to buy the satellite data, too! (Having already received a grant for the work, etc. etc.). No mention of TRF also is deliberate, but just in case a reader is thinking about TRF, they protesteth too much about how carefully they matched times and places for the data points and used the whole basket of satellites in a collaboratative way.
(Not) off topic:
Why is it that while Europe, from Britain to Siberia down to Spain and Portugal and Italy have been taken over by snowstorms and near record cold we do not hear anything form the MSM?
“In my opinion, the folks at NASA JPL really should …” shut the ‘H’ up about any ice loss and sea level rise claims until they have a handle on Terrestrial Reference Frame. They are showing themselves to be nothing more than political tools.
“An international team of satellite experts has produced the most accurate assessment of ice losses from Antarctica and Greenland to date, ending 20-years of uncertainty.”
Something akin to Maxwell Smart’s admission of ‘Missed it by that much’.
As for ending the uncertainty, all they have done is cast doubt on their current claims, by acknowledging their previous accurate claims were in fact inaccurate.
Do any of those posters eager to reject the finding of exceptional ice melting exceeding any since the start of the Holocene care to detail what error the problems with TRF impart to the data ?
Does it cause an error of less than 1%, less than 5% or more than 10% ?
Unless you know the magnitude of the error you cannot just discard data you dislike.
REPLY: In your zeal, you clearly don’t understand what is going on here. The error won’t be known until they can compare the data in hand to the stable baseline. – Anthony
Notwithstanding the Envisat story, even before the satellite data were considered unaffected by orbital decay… the sea level rise was minimum.
Actually, the science is fairly certain with Earth’s water (oceans and seas) levels. Mostly due to soil erosion, water levels are rising. It will take megatons of data, and megayears of arguing, to know with any certainty the rate of rise. To link the rise to CO2, is where the science stops and the BS begins.
All I want to know is when is my place back from the beach going to be prime Esplanade property?
I’m trying to tell the punters it won’t be long now and to get in early but the thick-heads are in denial.
How do I get the joint listed as a Terrific Reference Frame or whaddyamacallit thingy with these whitecoats to impress them? Do they do after hours assessments or do they just use Google Earth and I don’t really need to be there to let them in?
The sealevel data graph shows tidal guages and satellite data have different rates. What happened to the tidal guage data after 1992? Why don’t we see that data continuing to present?
Is this because it bad news for both sides, that there is an increased rate after 1992 but less than the altimetry data?
So the melting of ice might have contributed a 5th of the total measured sea level rise and this amounts to just 2 inches over the next one hundred years and this might be attributable to CO2 (except for the last 16 years cause there’s been no warming for 16 years). On this basis they want me to turn off my central heating?
@izen,
As Anthony pointed out in his direct reply to you, the magnitude of the errors to to TRF problems can not be known until a stable TRF is established.
If the error range is large enough that could actually mean that the real trend is the opposite sign from what the current satellite data show.
This means that none of the satellite measurements reliant on a TRF can be trusted until a stable TRF is established. Even the sign of the trend can not be trusted.
“Sheet Mass Balance Inter-comparison Exercise”
Translation: we did a ‘meta-analysis’ combining apples, oranges, pineapple chunks, corn syrup, and miniature marshmallows into a fruit salad and declared it nutritious.
First post.
Go Gentle please, been lurking for a while now
http://www.esa.int/esaCP/SEMP7ZE16AH_index_0.html?utm_source=dlvr.it&utm_medium=twitter
Another story to worry us (well, apparently)
“Northern hemisphere snow cover low record”
“faster than climate models”
I’m noticing a pattern. Regardless of whether these papers are support skeptical viewpoints or non-skeptic viewpoints it’s all happening at rates not predicted by the Models. All this tells me is that we still have no idea what is going on. So how can we possibly base any sort of policy on it? For now we just need to keep going, adapt to what ever is happening as it happens and if we ever get to the point where we can predict what is happening base policy on that.
^ Don’t think we’ll ever reach that point.
Yours a Liberal Skeptic.
Does anyone have a quick conversion factor between 100 Gt water = X mm Sea Level @ 4 deg C ?
The first chart with the red Tide Gauge and Blue Altimetry set me off. Another “Hide the Decline” in the making. We start measuring Altimetry in 1993, ok. But you expect me to believe that we STOPPED measuring Tide Gauges in 1993? No, they just stopped plotting the tide gauge data because — why? — it disagrees with the Altimetry? Hmmm?
“The lack of a stable TRF puts all of the space based geodetic data into question, thus the conclusions of the Shepherd et al paper are essentially worthless at the moment, since there isn’t any good way to remove the TRF error from the data with post processing.” You wanna bet, matey???? 🙂 They’ll find a way, that’s why they “reinterpreted” the satellite data, in an effort to “reconcile” it!
I have a real problem with people who want to “re-interpret” or “re-evaluate” something that didn’t show them what they wanted it to show, without “processing”, adjusting”, “refining”, or “smoothing” it afterwards to give them the picture they wanted to see!! Or is it just l’ill ol me? What a cynical old b’stard I have become in my seniority! They seem to have forgotton the fact that UNIPCC AR4 2007 SPM concurred that the Arctic was warmer in the 1940s than it is today, amongst many other things they “agree” with, particularly differences between satellite/radio sond temperature data & models being “largely resolved”, whatever that might mean!!! They just can’t seem to arrive at the logical conclusion without invoking the “Precautionary Pinciple”!
You guys are deluded if you imagine the TRF-uncertainty is big enough to change the current trend to an “opposite trend”. Check what the maximum size of the uncertainty is (hint: the JPL PowerPoint) and post it here please (I tried to do that when it was 1st reported but nobody on WUWT gived a damn).
Note also that the reference-frame affects altimetry- and gravimetry measurements differently and that it does not really affect the SAR/InSAR velocity measurements. SAR, altimetry and gravimetry show pretty much the same thing, as demonstrated in Shepherd et. al.
The GIA-models have a much larger uncertainty on Antarctica where one just cannot place GPS-stations where one pleases (no bedrock nearby on huge areas). On Greenland the problems are much smaller as the ice-sheet is relatively narrow and GPS-station can be places relatively nearby. Use of a different GIA-model will NOT reduce the Greenland mass-loss estimate by 50%.
REPLY: Look at the short period of Laser Altimetry data in Figure 4 – essentially flat. Note that LA is one of the keystones of the GRASP mission to clean up the noisy data which in table one has quite error bars. If you are makign bold predictions, would you not want to get the best available data?
And, why would you need to hide your identity at ESA if you are so sure of your claims? – Anthony
Stephen Rasey, there are zero tide-gauges in the open ocean, where incidentally much of the largest sea-level changes have happened. Referring to the satellite time-series is a much more comprehensive measurement of global sea level. Tide-gauges and satellite-data agree where they can be compared.
When I first read about the study I focused on the starting point, 1992. I then asked why they were not using data from tidal gauges. Tidal gauge data that goes back over 200 years shows us a 60 year cycle of up and down sea level. By using only 20 years when the tidal gauges were showing a rising sea level they of course end up with the results they did. It is the kind of “science” that con artists would use to convince the gullible.When dealing with cyclic events you always need to look at when the study starts and whether it includes at least one cycle. If it doesn’t, then the study is majorly suspect, unless it is noted that the study does not include a full cycle and was done in order to comply with grant requirments in which case it is again suspect.
Wow!! All we need is a new satellite!! The bid notice follows:
Notice to Bidders for NASAs GRASP
1. The work we want did is clearly showed on the attached plans and speserfacations. Our enganear, whose had plenty of college, spent one hell of a lot of time when drawed up these here plans and speserfacations. But nobody can think of everthing! Once your bid is in, that’s it, Brother! From then on, anything wanted by our enganear, or any of his friends, or anybody else (excep the contrakter) shall be cusidered as showed, speserfide, or emplide and shall be pervided by rhe contrakter without no expence to nobody, but hisself (meanin’ the contrakter).
2. If the work is did without no extry expence to the contrakter, then the work will be took down and did over again until the extry expence to the contrakter is satisfactory to our engangear.
3. Our engangear’s plans is right as drawed. If sumthin’ is drawed wrong, it shall be discuvared by the Contrakter, kerected and did right with no extry expence to us. It won’t cut no ice with us or our enganear if you point out any mistakes our enganear has drawed. If you do, it will be one hell of a long time before yu do any more work for use or him (meaning the engangear)!
4. The contrakter is not sposed to make fun of our enganear, his plans, or the kind of work we’re having did. If he do, it’s jest too bad for him (meanin’ the Contrakter).
5. Any Contrakter walkin’ around the job with a smile on his face is subject to review of his bid.
6. If the Contrakter don’t find all or our enganear’s mistakes before he bids on this job, or if the contrakter ain’t got enough sence to know that our enganear’s goin’ to think yp a bunch of new stuff that’s just too bad for him (meanin’ the contrakter)!
7. The Contrakter gotta use all good stuff on this job – none of this crap from Solyndra.
The laser altimetry is essentially flat since a) it was done on a campaign basis, not continuously and so it didn’t capture changes within years and b) the time-series is so short that the results depend on ice sheet “weather”. Shepherd et. al. nicely demonstrates the clear need for continuous long time-series to see what is really happening.
REPLY: “…to see what is really happening.” Agreed, they simply don’t know. This paper is just another guess based on noisy data, and having a stable baseline is key to that. There’s no getting around the need for a stable baseline – Anthony
Even IF the numbers are correct, where is the proof that any ice sheet loss is due to CO2? How does this match up with the fact that there has been no warming for 15 years? So, if even the ice sheets are shrinking there must be other exogenous variables involved, ie cloud patterns, storm systems, under sea volcanic activity, etc.
izen says: “Unless you know the magnitude of the error you cannot just discard data you dislike.”
Yet according to proponents of Global Warming one must accept conclusions derived from data with unknown magnitude of error. As in claim of 0.020** or 0.013** or 0.016** or 0.007** degree C rise in temperature per year based upon weather station data with an average error of +/- 1.86 degree C per daily reading.
**Pick your Global Warming Alarmist claim/prediction – which demonstrates the utter inaccuracies of Global Warming Faux-Climatologists, since they can’t even agree within 18% of each other.
According to JPL the TRF-related uncertainty is 0.45mm/year, see last slide here:
http://wattsupwiththat.com/2012/10/30/finally-jpl-intends-to-get-a-grasp-on-accurate-sea-level-and-ice-measurements/
REPLY: and if that were fully true, then they wouldn’t need to push for a new space platform and mission to correct the problem. Bottom line is we don’t know. All we have are estimates based on noisy data. If this were a skeptical paper, such things would be demanded, as it stands you give this paper a free pass, part of the problem with government funded group think of which you are a part. – Anthony
Liberal Skeptic says:
December 3, 2012 at 8:17 am
You failed to point out that the Northern hemisphere snow cover low record was for the month of June and the record is only 45 years long. Maybe Eurasia is having a drought? They make no statement about the rate of change of annual precipitation in the relevant area – I wonder if that’s reducing too?
Liberal Skeptic says: “All this tells me is that we still have no idea what is going on. So how can we possibly base any sort of policy on it?”
The scary part is not the possibility of Global Warming, but the world will enact inane policies based upon the recommendations / demands of Global Warming’s scientists (Faux climatologists), experts (self-proclaimed), and politicians (aka dictators).
“(Not) off topic:
Why is it that while Europe, from Britain to Siberia down to Spain and Portugal and Italy have been taken over by snowstorms and near record cold we do not hear anything form the MSM?”
Simple, high temperatures (the new normal) are global warming, low temperatures are just weather UNLESS they are really low, then it’s climate change. Got it?
I hope we’ve learned that if the satellites can’t be calibrated on the fly against a stable reference then launching them is a waste of money. Reminds me of the ACRIM vs PMOD debates.
CostCo says: “You guys are deluded if you imagine the TRF-uncertainty is big enough to change the current trend to an “opposite trend”. ”
What is deluded is those who assume that even if there is ice loss and a rise in sea levels, that it proves “Anthropological” global warming. All the claimed ice lose and rise in sea levels proves is Earth’s climate is undergoing a change, like previous changes in Earth’s climate long before man.
“REPLY: “…to see what is really happening.” Agreed, they simply don’t know. This paper is just another guess based on noisy data, and having a stable baseline is key to that. There’s no getting around the need for a stable baseline – Anthony”
It’s not a “guess”, but the best available multi-satellite estimate with quantified error-bounds. The TRF-error can influence sea-level measurements there the trend is few mm. per year but the ice sheet surface rises and falls orders of magnitude more per year and makes a 0.45mm/year uncertainty negligible. Heck, in some places and at some times the ice sheet surface is dropping 10+ meters per year!
Another example of how the moddlers use the Press Release to gather publicity for what ever it is they are pushing today. We expect that from politicians, religious leaders, soap and auto makers not from reputable scientists.
hum modelers is correct but perhaps moddlers should have been muddlers!
“REPLY: and if that were fully true, then they wouldn’t need to push for a new space platform and mission to correct the problem. Bottom line is we don’t know. All we have are estimates based on noisy data. If this were a skeptical paper, such things would be demanded, as it stands you give this paper a free pass, part of the problem with government funded group think of which you are a part. – Anthony”
The TRF-error and it’s maximum magnitude are known, not unknown. A more stable coordinate-system is required to reduce the error on sea-level trends that are of the order of 3mm/year, so 0.45mm/year is a considerable uncertainty. Over ice-sheets the TRF-error is negligible and certainly does not change the results.
The bottom line is that three largely independent techniques see the same signal. Greenland is losing mass a lot faster than only 20 years ago and some areas in Antarctica are changing too. There are the facts, causes can be debated until the cows come home but the fact remains that ice is being lost at an accelerating pace.
When I saw the errors: “….–142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1….” it blew my mind. How do you draw meaningful conclusions when the errors are that large?
We now have more accurate measurements of a bee’s digit.
I love the sentence. 😛 Specially during this century, when temperatures hasn´t changed a lil bit.
@CostCo says: 8:30 am:
there are zero tide-gauges in the open ocean, where incidentally much of the largest sea-level changes [verified how?, by what independent measurements?] have happened…..
Tide-gauges and satellite-data agree where they can be compared.
Then SHOW THE COMPARISON. Tide gauges were apparently good enough before altimetry data existed. Failure to continue the plot of the tidal gauge record only invites, nay demands, suspicion.
From the 23 stabel sites selected by Douglas in 1997, we get a sea level rise of about 1.4 mm per year measured over 200 years:
(From Wiki:,,, sorry! …. but I have seen the 1.4 mm fromm this study quoted elsewhere… bear in mind recent research shows groundwater extraction may contribute between 0.6 and 0.7 mm of that…
Original data for this figure is from the Permanent Service for Mean Sea Level [2] (PSMSL). Douglas (1997), defined the following criteria for selecting records from the PSMSL which were long, reliable, and avoided large vertical geologic changes:
1. Each record should be at least 60 years in length
2. Not be located at collisional plate boundaries
3. At least 80% complete
4. Show reasonable agreement at low frequencies with nearby gauges sampling the same water mass
5. Not be located in regions subject to large post-glacial rebound
Funny how previously all our scientific measures could be added up with great certainty to explain sea level rises of far great magnitude than that discussed here, and people went searching for and found “missing heat” …Then along came the groundwater guys who threw a small spanner in the works…but now we revise everything again and somehow it still all “adds up”.
Why is it that logic and ocean levels do not mix ?
(ref. Pacific Ocean Google search )
the Pacific Ocean is 165,200,000 square km, or 64.1 million square miles
1/3 of the worlds surface
1/2 of the worlds water
and the doctors with degrees in stupid say that they can measure not only this but the other half to 0.01mm ? ( 11.1 mm rise since 1992 )
How I ask do you calculate to 0.1 mm the moon affect ?
How do you calculate to 11.0 mm weather, 64 million square miles, flying from Hawaii to New Zealand takes a day out of your life and under you is only water !
in a class of 27, 14-15 year old’s only 8 could measure exactly how deep the water was in a 2 gallon bucket !
Actually its worse than we thought.!!
We now have accurate measurements of a bee’s digit
But nobody bother to calibrate our ruler. !
Billy Liar says:
December 3, 2012 at 9:03 am
“You failed to point out that the Northern hemisphere snow cover low record was for the month of June and the record is only 45 years long. Maybe Eurasia is having a drought? They make no statement about the rate of change of annual precipitation in the relevant area – I wonder if that’s reducing too?”
Quite, Such basic questions should at least be considered and checked for by an honest scientists and addressed in the conclusion, I wonder if they are in the full paper?
Stephen Rasey says: December 3, 2012 at 8:25 am
“….Does anyone have a quick conversion factor between 100 Gt water = X mm Sea Level @ 4 deg C ?…..”
This may help – ice, not water….
From Zwally etal 2011: 31 Gt ice loss per year from Antarctica is equivalent to +0.1 mm SLE (Sea Level Equation ??)
http://icesat4.gsfc.nasa.gov/cryo_data/publications/Zwally-Giovinetto_SurveysInGeophysics_2011-1.pdf
REPLY: and if that were fully true, then they wouldn’t need to push for a new space platform and mission to correct the problem. Bottom line is we don’t know. All we have are estimates based on noisy data. If this were a skeptical paper, such things would be demanded, as it stands you give this paper a free pass, part of the problem with government funded group think of which you are a part. – Anthony
###############################
According to JPL the TRF-related uncertainty is 0.45mm/year. The need for a new platform is driven by the desire to improve this. It is true that all we have are estimates based on noisy data. This is true for every measurement made in science. There is always noise. there is no getting rid of noise, no “stable baseline”. The question is how good ( uncertain) is the estimate? In the case of TRF it is good, but it can be better. Of course one can always spin the improvement of a process as an admission that it is all horribly wrong and highly uncertain. But looking at the actual numbers, one can see it for what it is. A good improvement to an already accurate system. All measurement is wrong. The issue is relative wrongness. All raw data is wrong. The issue is how wrong. So the “problem” of uncertainty will always be with us. There is no “correcting the problem.” There is only decreasing the uncertainty. You tend to frame this as if uncertainty in TRF renders all measurement useless. It doesn’t. There is now and will forever be an uncertainty in TRF. GRASP narrows that uncertainty it does not eliminate it. So for example, you wrote
“Taken together, these systems will improve the accuracy of the TRF, and thus the data. It’s rather amazing that the baseline accuracy didn’t come first, because this now puts all these other space based measurement systems into uncertainty until their TRF issues are resolved, and that’s an inconvenient truth. We’ll never look at satellite based sea level data or GRACE ice volume data in quite the same way again until this is resolved.”
The total uncertainty is .6mm/year. Of that .45mm/year is related to TRF. The noise in TRF
does not “put” “measurement systems into uncertainty” . All measurement has uncertainty. No science is settled. The “no spin” way to express this is : The uncertainty ( .6mm) is composed of TRF uncertainty. TRF uncertainty is a large component of the uncertainty. When the TRF uncertainty is reduced ( not eliminated ) by GRASP, the total uncertainty will be reduced. The TRF issue will never be “resolved” , the accuracy will be improved.
REPLY: And yet, they still didn’t take this into account. I find it gobsmacking that people at JPL don’t talk to one another, or that 47 scientists couldn’t/wouldn’t bring this issue to bear. Until the baseline is established, the measurements are in fact uncertain with a noise component. We don’t know what the true noise component is, all we have are estimates. And, we won’t know what the true magnitude is until such time that a stable baseline is established. I think all that hanging around the BEST folks has turned into a warmist. You talk like Rhodes now. – Anthony
All I know is that crocodiles swam in the arctic region many, many, many, many, moons ago, the Russians were using the NE Arctic passage commercially from the 1930’s onwards and underneath from Greenland to Siberia is a long line of Volcanoes that erupted a decade or so ago.
Any such paper that does not account for the uncertainty in Terrestrial Reference Frame is being knowingly and intentionally untruthful and misleading.
This is by far the biggest uncertainty in interpreting this kind of data and is known to be a major problem. This cannot have been “overlooked” by 49 different professional scientists.
The publishing of this paper seems to have been orchestrated to coincide with the beginning of COP18 in Doha. This yet more politics masquerading as science, which comes as no surprise when seeing Andrew Shepherd as a lead author.
kevin Kinser writes:
“My understanding of the significance, though, is that despite the uncertainty with any individual measurement, the combination of multiple sources reveals a common pattern.”
To get that result, you have to assume that the errors cancel one another. Real scientists do not make such assumptions but prove that the errors cancel one another. Does Shepherd’s paper provide such proofs?
If there’s ice loss in Antarctica, that doesn’t mean it’s melting–i.e., it’s not a proxy for global warming. It never gets above freezing there (except on the Peninsula). Ice will decline there, and in Greenland, if days are less cloudy than previously (= more sunlight), if the humidity is lower, if the wind is greater, and if snowfall declines. Sunnier, dryer, and windier days increase sublimation (evaporation w/o melting). Lower precipitation creates a net loss from year to year.
Another cause could be speedier glacier movement–which again isn’t a proxy for warmer weather. Glaciers move more quickly when there’s more weight accumulated at their upper ends from snowfall exceeding sublimation, and when obstacles t their lower ends are removed, such as when the end of a grounded glacier breaks off and becomes sea ice. These are random events, mostly.
(Right?)
Why does anyone with an understanding of this global warming business tout NASA as if it were a reliable source of data and science? Why praise it as a performer of heroic feats? It seems foolish and self-defeating, if you are a skeptic, to advertise NASA as a national shrine. With such praise, you confirm NASA in its course. To get them to change, you have to change public attitudes toward this agency. When a bee stings you,it has your attention,does it not? Same principle, wise up.
Beyond the issue with the satellite data and the non compliance with tide gauge measurements, there is more to put this into perspective:
Ice sheets have been melting most of the time since the last ice age. This is what would be expected.
There is nothing to see in Antarctica, (except increasing sea ice).
Greenland temperatures have just recaptured 1940s temperatures following the cyclic of AMO Once AMO turns negative in a couple of years, Greenland temperatures will follow.
Houston and Dean (2011) use more robust but not so fancy tide gauge data and conclude the OPPOSITE:
“Our analyses do not indicate acceleration in sea level in U.S. tide gauge records during the 20th century. Instead, for each time period we consider, the records show small decelerations
that are consistent with a number of earlier studies of worldwide-gauge records.”
http://www.jcronline.org/doi/pdf/10.2112/JCOASTRES-D-10-00157.1
CostCo says:
>>
Stephen Rasey, there are zero tide-gauges in the open ocean, where incidentally much of the largest sea-level changes have happened.Tide-gauges and satellite-data agree where they can be compared.
>>
And that doesn’t strike you as being problematic ??
It’s not that the satellites “agree” with tide gauges like it confirms they are correct to start with, they are explicitly and intentionally adjusted to be the same as tide gauges measurements. This is part of the calibration process. This says not more than they are _made_ to be the same.
Now the idea that all this (alleged) melt water is somehow choosing to pile up in the middle of the oceans where we have no means of checking its level seems a little odd without some solid theoretical reason why it should pile up where we can”t check it.
” Referring to the satellite time-series is a much more comprehensive measurement of global sea level. ”
More comprehensive cover does not mean it better, more accurate or worth believing. That needs to be established independently. Once that has been done, the more comprehensive coverage will be a distinct bonus.
For now that is not the case.
There is a much more obvious and likely conclusion to noting that the water is piling up in the middle of the ocean: the interpretations of the raw satellite data are consistently and seriously over-estimating the rise is sea level.
In fact this is precisely what was already established by JPL in the GRASP proposal.
“P. Solar says:
December 3, 2012 at 10:28 am
Any such paper that does not account for the uncertainty in Terrestrial Reference Frame is being knowingly and intentionally untruthful and misleading.”
That’s complete BS, please educate yourself. 0.45mm/year uncertainty is negligible compared with ice sheet elevation changes.
“This is by far the biggest uncertainty in interpreting this kind of data and is known to be a major problem. This cannot have been “overlooked” by 49 different professional scientists.”
It isn’t “overlooked”, you’re just wrong, see above for details.
Can I ask 2 silly/simple questions?
1) What are the error bands? 2 sigma? 1 sigma? Assuming what probability distribution? What was taken into account when calculating these errors? What wasn’t?
(I don’t have access to the original paper, even assuming the information is in there.)
2) No one has answered the question as to what the tidal gauges have been showing since the second half of the graph has been added. I know I’m a grumpy old cynic but this looks rather like a hockey stick again with two different merthods tagged together:
The price of apples went up by a certain amount over a 10 year period. But the price of oranges has gone up three times faster in the 10 years since then …
“REPLY: And yet, they still didn’t take this into account. I find it gobsmacking that people at JPL don’t talk to one another, or that 47 scientists couldn’t/wouldn’t bring this issue to bear. Until the baseline is established, the measurements are in fact uncertain with a noise component. ”
This issue is included in the error-assessment and it is negligible for SAR and altimetry. I seriously doubt that it would change the GRACE-results either.
“We don’t know what the true noise component is, all we have are estimates. And, we won’t know what the true magnitude is until such time that a stable baseline is established. […] – Anthony”
Nope, the magnitude of the uncertainty is known, please don’t succumb to hand-waving argumentation.
abstract: “We find that there is good agreement between different satellite methods—especially in Greenland and West Antarctica—and that combining satellite data sets leads to greater certainty. ”
Well it does not take much to increase certain peoples certainty when they are already in a state of belief. However this should not be read as meaning there is a reduction in the scientific measurement uncertainty.
Combining two datasets which do not have a common calibration base means you INCREASE the uncertainty of the result by adding in the uncertainty with which you are able to cross calibrate the two time series.
This is yet more of the false accounting that applies right across climate science, because if they were honest and rigorous in stating the true scientific uncertainty, most of the results would have >100% error bars and no one would be taking a blind bit of notice.
CostCo says: “Heck, in some places and at some times the ice sheet surface is dropping 10+ meters per year!”
Which does not necessarily indicate a loss of ice, instead it can indicate subsidence. But that tidbit wouldn’t conveniently fit with Al Gore’s CO2/GW Scam.
As for making wild alarmists claims, turnabout time – Heck, in some places and at some times the ice sheet surface is rising 10+ meters per year!
CostCo says: “This cannot have been “overlooked” by 49 different professional scientists.”
Never heard of Group Think or Herd Mentality, Eh?
CostCo says: “Nope, the magnitude of the uncertainty is known”
If that were true they wouldn’t be requesting more money for yet another satellite, would they!
Global Warming is a SCAM in part being used by Faux Climatologists to infuse their studies with funding at the expense of Taxpayer$
CostCo
I, for one, welcome your comments because it is always beneficial to have diverse viewpoints and you seem familiar with the issues. But you need to support your claim that the largest sea level changes occur in open ocean. How can that be?
My local survey crew can probably provide better data via landbased direct comparative measurement. The whole of the many issues here seems with making excuses to spend billions of others money on a non-issue. Send a memo: “If you live/work/own by the sea shore remember Atlantis.” It’s called “acceptable risk” as defined separately by each. 🙂
“And yet, they still didn’t take this into account. I find it gobsmacking that people at JPL don’t talk to one another, or that 47 scientists couldn’t/wouldn’t bring this issue to bear.” Anthony
Unlike Boeing, that can be sued for the landing gear failure because it did not fit properly into the gear well, public servants go unscathed in their inept turf protecting production of junk. A good manufacturing company in today’s world uses a common automated design system that is with one in all phases of development, so the landing gear fits the gear well. they can’t design a landing gear to fit into a gear well that does not fit, and vice verse; the 3d design CAD system won’t allow it.
You can make current measurements more accurate, but you CANNOT make past measurements more accurate.
If you establish a stable TRF now, you can only apply it to present and future measurements, Any “adjustments” to past measurements are just that, “adjustments”,, and we all know what happens when these are left in the hands of those trying to prove an agenda.
This continued mish-mashing of measurements made by different systems really is a fool’s journey !
““This cannot have been “overlooked” by 49 different professional scientists.””
all with noses in the trough.
“has error ranges larger than the data in some cases:”
Just stop right there. Do not pass go and do not collect $200.
Seriously? They can draw a conclusion with error bars that big? I call that a crap shoot myself and dicey this is.
Stephen Rasey says:
December 3, 2012 at 9:49 am
“…Failure to continue the plot of the tidal gauge record only invites, nay demands, suspicion.”
A point I have made. Where is the post satellite tidal guages record? Are we the only two who wonder where it is? It exists unless the observers have been force-moved to Siberian gulags.
Steven Mosher says:
December 3, 2012 at 10:08 am
The total uncertainty is .6mm/year. Of that .45mm/year is related to TRF.
Really?
http://www.osdpd.noaa.gov/ml/ocean/J2_handbook_v1-3_no_rev.pdf
OSTM/Jason-2 Products Handbook
2.3.1. Accuracy of Sea-level Measurements
Generally speaking OSTM/Jason-2 has been specified based on the Jason-1 state of the art,
including improvements in payload technology, data processing and algorithms or ancillary data
(e.g: precise orbit determination and meteorological model accuracy). The sea-surface height shall
be provided with a globally averaged RMS accuracy of 3.4 cm (1 sigma), or better, assuming 1
second averages.
The instrumental and environmental corrections are provided with the appropriate accuracy to
meet this requirement. In addition to these requirements, a set of measurement-system goals was
established based on the anticipated impact of off-line ground processing improvements. These
improvements are expected to enable reduction of sea-surface height errors to 2.5 cm RMS.
Knowledge of the stability of the system is especially important to the goal of monitoring the
change in the global mean sea level, hence a specification on the system drift with a 1 mm/year
goal.
From the table that immediately follows the above
Table 2 : Summary of error budget at the end of the verification phase
Altimeter noise 2.5 cm
Ionosphere 1 cm
Sea State Bias 3.5 cm (more on this later)
Dry Troposphere 1 cm
Wet Troposphere 1.2 cm
Altimeter Range 5 cm
RMS Orbit 10 cm
These collectively add up to nearly 25 cm, but with the application of appropriate statistical magic the sub total is reduced to a SSH error of 11.2 cm. Then comes the real fly in the ointment, the error for Significant Wave Height, which is given as 10% or 0.5 Meters, whichever is greater. SWH averages out at a little over 2 meters with peaks in the 8-9 meter range. On a daily basis SWH is present over about 95% of the world’s oceans. Although they generally admit they have yet to come close to resolving this error, they account for it in the above with that nice little 3.5 cm Sea State Bias uncertainty.
I would point out that this information is for the Jason 2 data which, due to improvements to instrumentation and processing, is probably at least an order of magnitude better than the TOPEX/POSEIDON era data, maybe even two. The changes to the instruments and methodology would seem to make it very problematic to attempt to combine the records into a coherent dataset.
CostCo says; “…the magnitude of the uncertainty is known,…”
Excellent. What is it?
NASA JPL presented the GRASP Mission Concept to the EGU in April 2009 in Vienna, Austria. “Promising revolutionary improvments to the definition of the TRF, its densification, and accessibilty. ” also “offering an inovative space-based approach to a heretofore intractable problem: establishing precise and stable ties between the key geodetic techniques used to define and disseminate the TRF. GRASP also offers a solution to another difficult problem, namely, the consistent calibration of the myriad antennas used to transmit and recieve the ubitqutious signals of the present and future Global Navigation Satellite System [GNSS].” It looks to me like NASA participated In,and spent money on , a study they knew from the beginning was far from robust, aka, WORTHLESS.
@markx 9:50 am From the 23 stabel sites selected by Douglas in 1997 …
I participated in a lengthy discussion about whether those stations were in fact stable with reason to doubt their stability. Look up “Is Sea Level Rise Accelerating.” WUWT May 16, 2012
May 16, (7:06 am – tectonic settings of stations used.) (7:30 am – Earth Tide)
(10:54 am – Thames flood barrier used to retain water in river.)
(11:13 am – too many fail tectonic setting. List of other places to try)
May 17 (11:26 am – Links to 20,000 yr Post glacial Sea Level charts)
(12:36 pm – more on other gauges. Tectonic Setting Map link)
(1:01 pm – Clustering and tectonic problems in Douglas)
May 20, (10:02 pm – More on clustering of the gauges used.)
May 28, (4:45 pm — PSMSL FAQ – up to 2000 mm of noise)
@markx 9:50 am From the 23 stabel sites selected by Douglas in 1997 …
I participated in a lengthy discussion about whether those stations in Douglas were in fact stable. I have reason to doubt their stability. Look up “Is Sea Level Rise Accelerating.” WUWT May 16, 2012
May 16, (7:06 am – tectonic settings of stations used in Douglas)
(10:54 am – Thames flood barrier used to retain water in river.)
(11:13 am – too many gauges fail tectonic setting. List of other places to try)
May 17 (11:26 am – Links to 20,000 yr Post glacial Sea Level charts)
(12:36 pm – more on other locations to try. Tectonic Setting Map link)
(1:01 pm – Clustering and tectonic problems in Douglas)
May 20, (10:02 pm – More on clustering of the gauges used in Douglas)
May 28, (4:45 pm — PSMSL FAQ – up to 2000 mm of noise in sea level from geoid)
Doug Proctor says:
>>
Stephen Rasey says:
December 3, 2012 at 9:49 am
“…Failure to continue the plot of the tidal gauge record only invites, nay demands, suspicion.”
A point I have made. Where is the post satellite tidal guages record? Are we the only two who wonder where it is? It exists unless the observers have been force-moved to Siberian gulags.
>>
This plot is based on the tide gauge record, from Jevrejeva 2008
“Recent global sea level acceleration startedover 200 years ago?”
http://i40.tinypic.com/nx3q1.png
(red dots and lines are mine)
Acceleration is a positive slope on the rate of change shown in the lower panel. There was accelerating rise in means sea level UNTIL the mid 20th century. Since then it is decelerating, with a residual rate of change around 2mm/y at the end of the data (this study’s data ends in 2002).
This paper was never about science, it was a propaganda piece timed to be released to bolster flagging spirits at Doha Round. As usual the usual Media suspects have responded as required and spread the misinformation before the public.
CostCo said : on December 3, 2012 at 9:20 am
And this despite temperatures in the Antarctic having fallen consistently for years. Presumably you can find a link for that apparent contradiction.
It’s the expansion of the universe that is being measured not sea level rise! 23mm per year or 71km/s/Mpc!
I always laugh when I see something like “new satellite readings show a change. in ………………”
Sorry, but compared to what………… readings from an old satellite?
Why was the old satellite replaced? Because it was inaccurate ?? DOH !!!
I happened to have flown over Greenland for the first time a few weeks back. Wow, impressive. I work in DOD, engineering, on satalite launch programs. I have trouble believing anything in space can accurately measure all of Greenland ice to within a meter. But the public believes our government can do anything.
Can somebody tell me how these satellite altimeters compensate for the inverse barometer effect where there are no measurements of the surface pressure?
In order to get accurate sea levels you have to have accurate simultaneous atmospheric pressure measurements.
Re Steven Mosher on December 3, 2012 at 10:08 am and Anthony’s reply:
It’s a simple issue. Steven Mosher knows he is a very smart guy. He is far too smart to ever be taken in by false claims and slick propaganda masquerading as real science.
Therefore because he accepted (C)AGW, there must be truth in it for him to have ever accepted it. So he will keep looking for more proof, which he will find as he must find it, since confirmation of the reality of (C)AGW is confirmation of his smartness.
Which means that Anthony, I, and millions of other people who formerly accepted (C)AGW before rejecting it as unproven hyped-up nonsense, and all of those who never accepted (C)AGW, are stupid, clearly not as smart as Mosher. We must be stupid, as we reject the science that Mosher finds so clear and convincing, that convinces Mosher he’s as smart as he always knew he was.
It’s expected he’ll sound more like a warmist, as becoming even more convinced of (C)AGW is more confirmation of his smartness, and more confirmation that those who disagree with him on the science must be stupid.
Take note there are many thousands of Mosher’s out there, of many varieties, convinced their investments in Green energy companies will pay off someday, that the politician they supported and voted for will do what they promised if the obstructionist opposition wasn’t preventing them from doing the right thing. Good con men of all stripes love and appreciate such very smart people.
” mpainter says: But you need to support your claim that the largest sea level changes occur in open ocean. How can that be?”
I’m not an expert on sea-level but I guess that the largest warming has happened over the open ocean and then the thermal expansion takes care of the rest.
“Darren Potter says: CostCo says: “Heck, in some places and at some times the ice sheet surface is dropping 10+ meters per year!”
Which does not necessarily indicate a loss of ice, instead it can indicate subsidence.”
Subsidence of bedrock or what? Anyway, the surface velocity of the ice is known, which can be used to infer what is going on.
“J Martin says: CostCo said : on December 3, 2012 at 9:20 am
Heck, in some places and at some times the ice sheet surface is dropping 10+ meters per year!
And this despite temperatures in the Antarctic having fallen consistently for years. Presumably you can find a link for that apparent contradiction.”
Sea-water has warmed up in some areas around Antarctic and melted the ice-shelves and ice-streams from below.
“ntesdorf says: This paper was never about science, it was a propaganda piece timed to be released to bolster flagging spirits at Doha Round. As usual the usual Media suspects have responded as required and spread the misinformation before the public.”
Yeah, right, a landmark Science-paper by most of the best research teams in the world is not “science”. Nice try.
Rob Dawg says: CostCo says; “…the magnitude of the uncertainty is known,…”
Excellent. What is it?”
As already indicated a few times, the error has been circled on this slide from JPL:
http://wattsupwiththat.files.wordpress.com/2012/10/grasp_impact.png?w=640&h=380
P. Solar says:
This plot is based on the tide gauge record, from Jevrejeva 2008
“Recent global sea level acceleration startedover 200 years ago?”
http://i40.tinypic.com/nx3q1.png
———————–
Why would anyone prefer satellite data over tide gauge data ?
Sea level changes are so tiny, that any changes on board, equipment drifts, heat sources, orbit changes, satellite rotation, atmospheric pressure, atmospheric consistency, atmospheric extent, solar variation etc will cause not only noise but also bias. So many known unknowns and unknown unknowns, proven to exist by the never ending stream of new sorts of data adjustment..
Tide gauge data is still noisy, but the only bias may come from land going up or down, which is 1) adjusted for and b) rest error should cancel over all coastlines.
Does that data match this data:
http://motls.blogspot.com/2012/12/sea-level-rise-is-most-reliable-way-to.html ??
What acceleration?
P. Solar says:
December 3, 2012 at 1:18 pm
Thanks for the plot!
Coarse, goes only 8 years beyond the satellite start of 1992, we’re still missing another 11.
Not sure that the resolution will enable me to layer it on with any meaning. The change/yr seemed to be going down. The last 11 years would tell the tale.
[“Of course” instead? Mod]
This looks like a more balanced discussion of the Greenland Ice Loss Study. http://www.princeton.edu/main/news/archive/S35/40/38C46/index.xml?section=topstories
The paper in Science…the abstract stated…
“Between 1992 and 2011, the ice sheets of Greenland, East Antarctica, West Antarctica, and the Antarctic Peninsula changed in mass by –142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1, respectively. Since 1992, the polar ice sheets have contributed, on average, 0.59 ± 0.20 millimeter year−1 to the rate of global sea-level rise.”
As you will note the errors are quite large…so the net ice loss for the planet ranges from -88 Gt/yr to -354 Gt/yr and global sea level rise ranges from 0.39mm to 0.79mm per year. This is a very small amount. In other words over a 50 YEAR PERIOD we can expect the sea level (assuming the melt rate stays steady) to rise somewhere between 19.5mm to 39.5mm. This is roughly somewhere between 0.76 inches and 1.55 inches…!!!
Antarctica currently contains roughly 30 million cubic kms of ice. Remember that 1 cubic km of ice weighs about 1 gigatonne, so Antarctica contains 30 million gigatonnes of ice and so it appears from this publication that Antarctica is losing roughly 71 gigatonnes per year.
Also this estimate has large error estimates, if we put these errors in then the following applies… East Antarctica ranges between +57 to -29 Gt/yr and West Antarctica ranges between -39 and -91 Gt/yr and the peninsula ranges between -6 and -34 Gt/yr….so if we take the positive gain in East Antarctica (+57) and add it to the lower losses elsewhere in Antarctica we could possibly have a net gain…this is probably unlikely. These figures IMHO are no cause for alarm.
Anyone want to download 2149 tide gauge records (some with data up to Oct 2012) and then collate all that data into a trend of sea level rise over time:
http://www.psmsl.org/data/obtaining/rlr.monthly.data/
What is interesting is the [shear] effort going into collecting this data by hundreds of organizations around the world and then making it virtually/completely impossible to be able to calculate a trend from it.
One would then have to compare these individual records to the local land uplift/subsidence records from GPS receivers here in order to be accurate:
http://www.sonel.org/IMG/txt/ulr5_vertical_velocities_table.txt
Station identifiers here:
http://www.sonel.org/spip.php?page=cgps
And then one could actually calculate the level of sea level rise over time without having to resort to a global warming-based isostatic model.
But this is months of work. Why is this made so difficult when they have all the data.
Billy Liar says:
December 3, 2012 at 2:13 pm
Can somebody tell me how these satellite altimeters compensate for the inverse barometer effect where there are no measurements of the surface pressure?
In order to get accurate sea levels you have to have accurate simultaneous atmospheric pressure measurements.
From the JASON 2 data products handbook I linked above
5.10.1. Inverted Barometer Correction
As atmospheric pressure increases and decreases, the sea surface tends to respond hydrostatically, falling or rising respectively. Generally, a 1-mbar increase in atmospheric pressure depresses the sea surface by about 1 cm. This effect is referred to as the inverse barometer (IB) effect.
The instantaneous IB effect on sea surface height in millimeters (see parameter inv_bar_corr) is computed from the surface atmospheric pressure, Patm in mbar:
inv_bar_corr = -9.948 (P – P) ∗ atm
where P is the time varying mean of the global surface atmospheric pressure over the oceans.
The scale factor 9.948 is based on the empirical value [Wunsch, 1972] of the IB response at mid latitudes. Some researchers use other values. Note that the surface atmospheric pressure is also proportional to the dry tropospheric correction, and so the parameter inv_bar_corr approximately changes by 4 to 5 mm as model_dry_tropo_corr changes by 1 mm (assuming a constant mean global surface pressure). The uncertainty of the ECMWF atmospheric pressure products is somewhat dependent on location. Typical errors vary from 1 mbar in the northern Atlantic Ocean to a few mbars in the southern Pacific Ocean. A 1-mbar error in pressure translates into a 10 mm error in the computation of the IB effect.
Note that the time varying mean global pressure over the oceans, P, during the first eight years of the T/P mission had a mean value of approximately 1010.9 mbar, with an annual variation around this mean of approximately 0.6 mbar. However, the T/P data products provided a static inverse barometer correction referenced to a constant mean pressure of 1013.3 mbar.
IB(T/P) = -9.948 (P -1013.3) ∗ atm
Sea surface heights that are generated after applying an inverse barometer correction referenced to a mean pressure of 1013.3 mbar are therefore approximately -9.948*(1010.9-1013.3) = 23.9 mm lower than those that are generated after applying an inverse barometer correction referenced to a time varying global mean pressure, and the difference between the two sea surface heights has an annual variation of approximately 9.948*0.6 = 6 mm.
Reminds me of the election polling by Nate Silver’s 538 blog? When you pool the data you tend to get more accurate results. I think the righties are going to like this study about as much as they liked Nate’s prediction. Math can be a bitch. JP
Thanks, Anthony, I’m quoting you and linking to this article.
Jet Propulsion Laboratory (JPL) admits that satellite measurement of the Earth has issues because a stable Terrestrial Reference Frame was never established for any of the satellite programs.
Liberal Skeptic says:
December 3, 2012 at 8:17 am
First post…..
______________________________________
I think this is the more important piece of information since it is when snow cover starts in the fall in the Northern Hemisphere. And that snow cover is INCREASING graph
It seems Ma GAIA didn’t get the CAGW message or maybe she is just thumbing her nose at Doha
December 2, 2012: Cold front to bring blizzard to NE China
December 02, 2012 Russia Scrambles To Cope With Monster Snowfall
02 December 2012 Snow Continues As Mercury Plunges: Forecasters are warning of more snow in parts of Britain after temperatures plunged as low as -6C overnight.
01 december Snowstorm causes major problems on E4: After intense snowfall – with a meter of snow in many parts of Sweden – sections of the E4 motorway were blocked on Saturday afternoon
1 Dec 12 Record lows as winter freeze grips Sweden
Anomalous winter disasters paralyze Moscow: Moscow was literally paralyzed at night of November 30. The city and the region experienced two natural disasters in one night: a super heavy snowfall and an ice storm.
Blizzard in Estonia: If the week’s previous weather was a snowstorm, this one was a blizzard,” …A fresh snowstorm arriving on Thursday evening from the southeast buried much of the country – with some places gaining up to 27 centimeters of fresh snow
FINLAND: 30,000 blacked out by snowstorm: Tens of thousands of households were without electricity on Friday as a result of a storm that dumped heavy snow across southern Finland
Winter’s first cold snap hits Fairbanks: This month is going to be in the top few coldest Novembers of record,” ….That would put it just ahead of November 2011, which ranked as the sixth-coldest November on record
Severe Snow Storm Hits Northern Japan: Northern Japan has been blasted with an intense snow storm today as northwesterly winds pelted the region causing widespread havoc to residents in Hokkaido and Northern Honshu. Winds gust up to 152kph in Japans northernmost prefecture knocked out power for at least 40,000 residents
27 November 2012 Britain faces coldest winter for 100 years as Big Freeze follows floods with wind so strong it blows water upwards
Snowfall paralyzes life in China: China has experienced the biggest snowfall in 52 years …Temperatures were brought down by as much as 14 degrees below zero in some areas
CHINA: Worst snow in 50 years damages 400 greenhouses…in Hegang, China’s Northeast Heilongjiang province on Nov 15, 2012.
Snowfall freezes Kashmir valley: first snowfall of the season has yet to arrive in Srinagar, but the temperature has reached below zero degree for the first time this season…continuous snowfall over the last two days…temperatures have dropped to minus six degree in Kargil and Dras.
Pakistan Heavy snowfall: Nathia Gali including its surroundings 4 to 5 feet snow fall by …Snowfall season has been continuing since last 2 days …. Snow fall also is continuing in upper areas of Azad Kashmir.
Smoky Mountains: A record amount of snow fell across the higher elevations in October
October 28, 2012, Low Temperature Record Set In Central Texas
As Steven Goddard shows below
http://stevengoddard.wordpress.com/2012/12/03/more-sea-ice-than-on-this-date-in-1979/
” On this date in 1979, there was 20.15 million km^2 of sea ice on Earth. Today there is 20.20 million km^2.”
Where’s the ice loss?
CostCo says: “Subsidence of bedrock or what?”
You really are in over your head if you don’t understand how that could give false GW Alarmist readings.
CostCo says: “… the surface velocity of the ice is known, which can be used to infer what is going on.”
Infer as in take a Educated Wild Arse Guess.
As for SAR/InSAR velocity being known, go read up on what can effect SAR accuracy before you make such statements.
Darren Potter says: @ December 3, 2012 at 9:07 am
….The scary part is not the possibility of Global Warming, but the world will enact inane policies based upon the recommendations….
_____________________________
The really scary part is the politicians will give the great unwashed very expensive/scarce energy and food and THEN we head into another Little Ice Age or even worse the big plunge.
We know diddly squat about what really drives climate because the money interests have been backing CO2 to the exclusion of anything and everything else. This means the world governments can easily get caught flatfooted if TSI is NOT the solar forcing that has the major impact on climate but something else like the solar magnet field or UV does as certain papers indicate. The cycles are there. Too many papers from different parts of the world using different methods support solar cycle, temperature/precipitation cycles for there to be any doubt.
Ag interests have already convinced the USA NOT to have a strategic grain reserve but to rely on BUYING grain if needed. The USA produces 25% of the world’s grain BTW.
Here is Poptech’s list of just the 1500 year cycle. The solar list is much longer. (Papers are linked at his site)
1,500-Year Climate Cycle
A Pervasive Millennial-Scale Cycle in North Atlantic Holocene and Glacial Climates
(Science, Volume 278, Number 5341, pp. 1257-1266, November 1997)
– Gerard Bond et al.
Late Holocene approximately 1500 yr climatic periodicities and their implications
(Geology, Volume 26, Number 5, pp. 471-473, May 1998)
– Ian D. Campbell et al.
The 1,800-year oceanic tidal cycle: A possible cause of rapid climate change
(Proceedings of the National Academy of Sciences, Volume 97, Number 8, pp. 3814-3819, April 2000)
– Charles D. Keeling et al.
Timing of Millennial-Scale Climate Change in Antarctica and Greenland During the Last Glacial Period
(Science, Volume 291, Issue 5501, pp. 109-112, January 2001)
– Thomas Blunier et al.
Widespread evidence of 1500 yr climate variability in North America during the past 14 000 yr
(Geology, Volume 30, Issue 5, pp. 455-458, May 2002)
– André E. Viau et al.
Decadal to millennial cyclicity in varves and turbidites from the Arabian Sea: hypothesis of tidal origin
(Global and Planetary Change, Volume 34, Issues 3-4, pp. 313-325, November 2002)
– W. H. Bergera et al.
Timing of abrupt climate change: A precise clock
(Geophysical Research Letters, Volume 30, Number 10, pp. 17-1, May 2003)
– Stefan Rahmstorf
Possible solar origin of the 1,470-year glacial climate cycle demonstrated in a coupled model
(Nature, Volume 438, Number 7065, pp. 208-211, November 2005)
– Holger Braun et al.
The origin of the 1500-year climate cycles in Holocene North-Atlantic records (PDF)
(Climate of the Past, Volume 3, Issue 2, pp.679-692, 2007)
– M. Debret et al.
Global Warming Every 1,500 Years: Implications for an Engineering Vision (PDF)
(Leadership and Management in Engineering, Volume 8, Number 3, pp. 153-159, July 2008)
– Dennis T. Avery
Holocene temperature records show millennial-scale periodicity (PDF)
(Canadian Journal of Earth Sciences, Volume 47, Number 10, pp. 1327-1336, October 2010)
– Craig Loehle, S. F. Singer
CostCo says: As already indicated a few times, the error has been circled on this slide from JPL:
And as already indicated several times, “The uncertainty is quite clear in Table 1, which has error ranges larger than the data in some cases”.
As you can see, we too can play the repeat game.
richard says:
December 3, 2012 at 10:21 am
All I know is that crocodiles swam in the arctic region many, many, many, many, moons ago, the Russians were using the NE Arctic passage commercially from the 1930′s onwards and underneath from Greenland to Siberia is a long line of Volcanoes that erupted a decade or so ago.
___________________________________
And do not forget the undersea volcanoes in Antarctica.
I can understand your beef with the altimetry and interferometry data in the paper but I don’t see how it affects the gravimetry data.
First, even with your argument, I think it’s safe to say that the data for Greenland is safe. The altimetry and interferometry data shows an average loss of 7 cm for the entire subcontinent using a machine that measures ocean surface in mm’s. So whether it’s 6 cm or 7 cm, a lot of ice is missing, and this is consistent with other recent reports.
But the Antarctic data is thinner, averaging about 1/2 cm loss over the entire continent.
Here’s where the gravimetry data really buttresses the paper. I don’t know how the gravimetry units work, but the satellite measures local changes in gravitational acceleration, and this correlates with local mass. The simple way to look at the gravimetry data is 1) whether it’s going positive or negative, and 2) its magnitude. The correlation of the gravimetry data with the altimetry and interferometry data was beautiful addition to the paper, and is hard to argue with. For example, in the West Antarctic data, the altimetry and interferometry data shows a loss, and so does the gravimetry data.
The other parts of the Antarctic data that are convincing are the local differences. That is, in places where there are other reports showing that the area is warming, the ice ablation is higher (West Antarctic) and where it is cooling, lower (East Antarctic).
CostCo says: ” a landmark Science-paper by most of the best research teams in the world is not “science”.
Well since it is a “landmark Science-paper” by “most of the best” research teams in “the world” then it must be absolute disputable fact. Like there were nine planets, huh? /sarc
mpainter says: @ December 3, 2012 at 12:00 pm
But you need to support your claim that the largest sea level changes occur in open ocean. How can that be?
____________________________________
Trade Winds.
http://www.youtube.com/watch?v=lmjaNO5DD_Q
Gail Combs says: “… THEN we head into another Little Ice Age or even worse the big plunge. ” “We know diddly squat about what really drives climate because the money interests have been backing CO2 to the exclusion of anything and everything else. ”
Exactly, since we don’t understand what caused past climate changes, thanks to AGW group think and self-serving interests, and given proponents of AGW having been 0 for 30 on their dire warming predictions, it is remotely possible that an increase in CO2 leads to Global Cooling. Or more likely CO2 has no effect and we have been wasting resources looking at the wrong thing.
I am not surprised the Greenland ice sheet has decreased lately, because a few years ago, before finding Anthony’s informative blog, I stumbled across a website that detailed the temperature of the Gulf Stream (which flows to Greenland), and it showed that its SST has been increasing. So, that warmer water plus the warmer air blowing over it would naturally cause the Greenland ice sheet to recede, consequently, eliminating a need to invoke an AGW scenario when there exists a plausible physical effect.
I did not maintain “notes” back then, so I cannot provide a link. Shouldn’t there also be a SST site for the warm waters flowing north along the eastern Asian continent?
Most folks that went to junior high 45-50 years ago know that the earth is essentially an elastic ball of liquid and that the weight of all that ice in the Antarctic has severely depressed the underlying crust. Just like a balloon full of water, the effect of subsidence with more ice or some other tidal effect causing additional subsidence will cause an apparent sea level with no melting
Involved.
I am wondering if one of the fine minds in this free for all knows the answer to the following? GPS satellites have their clocks offset prior to launch due to the relativistic effects of gravity. Is there additional compensation applied due to the effects of variations in the earth’s gravity, the position of the moon, sun, Jupiter, etc? That would be a lot of look up tables.
It DOES change. I have a close friend who is a civil engineer. These reference points constantly drift on all three axes. The movement is checked and a new “epoch” is created. Surveys done in one “epoch” must have the drift of the benchmark accounted for if they are being applied to the current “epoch”. If you have a datum from 1973, it may not be in the same location in 2012. It might have moved a foot or more depending on where it is and how long ago the survey was done.
Bill Innies says:
>>
http://www.psmsl.org/data/obtaining/rlr.monthly.data/
What is interesting is the [shear] effort going into collecting this data by hundreds of organizations around the world and then making it virtually/completely impossible to be able to calculate a trend from it.
>>
The calculation is non trivial. There was a considerable amount of work went into Jevrejeva’s papers. Worth reading. http://www.google.fr/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&ved=0CDcQFjAB&url=ftp%3A%2F%2Fsoest.hawaii.edu%2Fcoastal%2FClimate%2520Articles%2FJevrejeva_2008%2520Sea%2520level%2520acceleration%2520200yrs%2520ago.pdf&ei=2qS9UN_TLMKf0QWd4oGYDw&usg=AFQjCNGvmifObtaLVSM3_pS2tUdprOYgpg
It would be very informative to see this same analysis updated to take account of the last ten years.
When the satellite data is presented in an easy to read form by Colorado U. they automatically add their GAIA [sic] adjustment and no longer provide the data without the barometer adjustment.
Why the barometer adjustment? Pressure difference can only displace water from one place to another, not alter GMSL. The fact that we get this and only this prevents comparison and suggests there IS a difference (if not, why use it to calculate _global_ sea level). Any such difference MUST be a corruption since air pressure cannot create water !
This whole area is now corrupt science.
CostCo says:
December 3, 2012 at 2:15 pm
>>
” mpainter says: But you need to support your claim that the largest sea level changes occur in open ocean. How can that be?”
I’m not an expert on sea-level but I guess that the largest warming has happened over the open ocean and then the thermal expansion takes care of the rest.
>>
Cool. So a) it has little to do with melting ice sheets after all; b) since the main worry humans have about rising waters is coastal flooding we can be reassured by these readings showing the it just safely piles up in mid ocean where it is not a problem.
There is of course a simpler explanation to why you find sea levels rising anomalously everywhere except where they are constrained by other tangible data: the calibration of the satellite positions have systematic errors.
That much should be obvious to anyone with a basic training in scientific method.
trafamadore says: “The correlation of the gravimetry data with the altimetry and interferometry data was beautiful addition to the paper, and is hard to argue with. For example, in the West Antarctic data, the altimetry and interferometry data shows a loss, and so does the gravimetry data.”
Gravity data from GRACE does not show ice loss , it shows gravity changes. How anyone chooses to interpret that depends on models of how the underlying bedrock is moving. Earlier models were largely guesswork. More recent measurements from a small number of GPS monitors that are possible in some areas have massively changed the presumed ice change from ice loss to ice gain. It seems this paper is still using the older model , though I’m not going to pay $44 to read the results of research I’ve already paid for to check.
Equally the other techniques only measure the top of the ice they do not measure thickness, so they tell us even less than GRACE about ice mass.
There is no “beautiful” addition. The fact the _relative_ changes by various methods show similar short to medium term variation is encouraging but does not address the fundamental calibration issues that undermine efforts to determine long term loss/gain of ice mass.
This paper is trying to confuse the two. To suggest short term correlations reduce the uncertainly when the underlying calibration problem remains unresolved.
Astounding. Really it is. They didn’t think about this before spending how many $Millions (or is it with a $B now?) on ‘noise makers’?
I’ve also got to wonder if the recent plunge in solar UV, change of the energy state if the upper atmosphere, and overall change in atmospheric height is going to play Hob with the radio data too…
So we have a huge pile of noisy satellite data, and a big pile of fudged and distorted land data (at least for temperatures). In short, we don’t have a clue what the real data are saying. Yet some folks think if they just average it all together then can get microscopic precision.
AGW is Garbage Science on a fat paycheck. Just garbage.
“P. Solar says: Gravity data from GRACE does not show ice loss , it shows gravity changes.”
Yes, and the very cool thing demonstrated in Shepherd et. al. is that a very snowy year on East Antarctic coast is visible in both gravity and altimetry measurements, as well as the precipitation model. The same signal is visible in these independent datasets, which increses the confidence in the results a great deal. If there was only GRACE or only altimetry, we could not be as confident about the result as we are now.
So, the acceleration of the Greenlandic mass-loss is a verified scientific fact, not empty speculation.
@-“In your zeal, you clearly don’t understand what is going on here. The error won’t be known until they can compare the data in hand to the stable baseline. – Anthony”
Wrong.
The exact value of the error may require further research, but the size, in terms of order of magnitude is inherently constrained. It isn’t credible to claim that it could be large enough to reverse the sign of the trends found.
More to the point, the alternative methodologies that do not rely on the TRF further constrain the error range. As another poster has pointed out by combining the results from different sources with independent error ranges a final result with a much smaller error range can be derived often by Baysian techniques, as Nate Silver did with the polling data.
Every month hundreds of pieces of research Are published into climate change. None contradict it. If they did they would be be trumpeted here very loudly, but 100% of the evidence supports AGW.
@-E.M.Smith
“In short, we don’t have a clue what the real data are saying. Yet some folks think if they just average it all together then can get microscopic precision. AGW is Garbage Science on a fat paycheck. Just garbage.”
‘Some folks’ are right, combining multiple data from different sources does minimise errors, but just as with lead, asbestos, CFCs, DDT and of course tobbaco the message that they do harm is unwelcome to those with a financial or ideological interest in the status quo of exploiting these products. As for the fat paycheck, less than one minute of exxon’s profit would pay for this research.
The enthusiasm that some show here to dismiss the data in its entirety when the error CAN be calculated and minimised is typical of those who are motivated to reject the science.
Here’s a not-very-recent paper on the TRF-errors and altimetry:
http://w3admin.ipgp.jussieu.fr/docs/recherche/planeto/Morel05.pdf
11mm in 2 decades. On average the south coast of Britain has been dipping by 10mm per decade since the last ice-age. Has this led to the destruction of civilisation, the end of humanity? The failure of economic systems?
@Mike Haseler:
Parts of California change elevation by FEET in minutes. The process is a bit shaky, but life goes on 😉
@Izen:
Averaging can remove random error but does nothing to remove systematic error. A bogus benchmark for your measurements is a systematic error.
Note, too, that I specifically said “microscopic precision”, i.e. an assertion about size of the error band (even if in a poetic form). I did not assert there was zero ability to improve resolution (for random error sources).
In short, the error band on the data is about as wide as the “warming” being found. It is a systematic error band. Averaging will not reduce it. The AGW conclusions are, thus, garbage. (Due to failure to understand the difference between systematic and random error, over averaging as an article of faith, splicing disjoint data sets, ignoring actual error bands, and confusing TEMPERATURE with HEAT in a calorimetry problem. Among other things…) Frankly, it doesn’t measure up to even High School Science standards of work quality (where, at least in my High School, one had to have a clear understanding of why temperature needed mass and specific heat values to calculate heat change… and why you could not average out systematic error.)
Stephen Rasey says: December 3, 2012 at 1:14 pm
“From the 23 stable sites selected by Douglas in 1997 …
….I participated in a lengthy discussion about whether those stations in Douglas were in fact stable. I have reason to doubt their stability…”
I think you may very likely be correct – but the gauges may be the most accurate data we have, if one reads the details of the problems of satellite calibrations… amazing work they do.. having to cobble together data from four different systems. And it sounds to me like GRACE may be a bit of a dud, noting they failed to tune antennas to the spacecraft …..
But in the end using the Douglas 1997 ref gauges gives us 1.4 mm a year, substantially less than the satellites give us …. and correct me if I’m wrong, but surely the tidal guage data is most relevant to us? Eg if the sea was rising at 3 mm per year but all the land in the world was rising at 4 mm per year …. well, there is not a problem, is there?
Note this 1.4 mm/year above includes an allowance of 0.3 mm per year made for glacial isostatic adjustment (GIA which is a gradual enlargement of the ocean basins in response to the retreat of the great glaciers some 12,000 years ago). So really actual is back to 1.2 mm/year…..
On that topic – intriguing work by Gomez etal (supervisor is Jerry Mitrovica) shows that sea level rise is in response to polar ice melt is not uniform. (modelled, but compelling…)
The loss of gravitational effect of ice loss at the poles will mean sea levels at the poles retreat markedly with ice melt (hey, self limiting effect on ice caps of warmer seas!) and the greatest rise is at the equator, the worst effect being west Atlantic – NY)…
Amazing stuff … and I wonder at the impact of Gomez’s work on the above mentioned tide gauge data? 13 of the Douglas sites are Atlantic, equatorial region …. I’m thinking that may mean 1.1 mm/year of sea rise at these equatorial regions may well imply there is far less ice loss than calculated …
http://www.nipccreport.org/articles/2011/mar/16mar2011a4.html
Re gravitational effects of ice caps: In a video (very pro CAGW) Mitrovica said if you were standing at the waterline of Greenland, and could instantly melt its ice, the sea at your feet would FALL 100 metres due to the lost gravitational effect ….. the water would pool closer to the equator.
http://youtu.be/RhdY-ZezK7w
Jerry Mitrovica – Professor of Geophysics at Harvard University in the USA.
@- E.M.Smith
I do know that averaging will not reduce systemic errors, which is why I never mentioned averaging in my post. That seems to be a wrong assumption on your part.
I still regard rejecting as you do all the research in the last sixty decades on AGW as motivated by issues other than scientific insight. The comment it is a means of getting a fat paycheck perhaps is projection and reveals a fear that dealing with the thermodynamic consequences of rising CO2 might impact the fat paycheck the fossil fuel industry gets.
CostCo:
I have been following this thread with interest, and I notice that until recently you were ‘defending the fort’ alone, but the ‘usual suspects’ (izen, trafamadore, etc.) have started to come to your aid. This is not surprising because, at first, it seemed you knew something about the subject and could defend the paper by Shepherd et al. from criticism, but your defences have been so pathetic that you clearly need help.
Several clear criticisms have been made and they fall into two categories;
1. The satellite system does not have adequate accuracy
and
2. The satellite system is a flawed method that cannot have adequate accuracy.
Your responses have amounted to arm-waving assertions or completely ignoring a stated criticism. Before addressing specific points as illustration of your failure to address the issues, I point out that your arm-waving has become like the flailing of a demented Dervish. For example, your post at December 3, 2012 at 2:21 pm says in total
The paper is “a landmark Science-paper”?! Really?
The paper reports that additional work costing a fortune failed to provide the measurement improvement it was intended to obtain so the paper calls for another fortune to be spent on giving them another attempt at the improvement.
The paper is not a “landmark”: it is a report of an expensive failure.
Importantly, the failure was ‘dressed up’ as being a move forward in a press release coincident with the Doha COP. Correlation does not prove causation but in some cases it can be very indicative.
And people with a track-record of failure do not constitute “most of the best research teams in the world”. They represent failures.
Please note that the paper has 47 co-authors; n.b. not ‘signatories’ but co-authors. People who do good work like to take the credit and they don’t seek co-authors. People who are publishing because they have to report what they have done seek co-authors because they want to share the blame. Hence, good papers never have dozens of co-authors.
You say you think the paper is “science”. I agree in that any report of a failure is information which is useful to science, but the nature of the Shepherd et al. paper and its press release are pure PR and not “science”.
Which returns us to the two categories of criticism.
The paper reports that the satellite system does not have adequate accuracy. As oeman50 succinctly stated at December 3, 2012 at 9:33 am
Of course, the answer to his question is, you can’t.
And the satellite system is a flawed method that cannot have adequate accuracy. The above article highlights the problem of TRF errors which remain unresolved and so prevent the system having adequate accuracy. Of course, in theory it may be possible to solve the TRF problem within the lifetime of the satellite system, but Billy Liar raised an even more fundamental problem in his post at December 3, 2012 at 2:13 pm where he asked and correctly stated
Of course, nobody knows how to obtain an answer to his question and, therefore, his correct statement means it will not be possible within the lifetime of the existing satellite system for the method to provide the required accuracy except by adopting an unjustifiable assumption that average barometric pressure remains constant.
In conclusion, the paper by Shepherd et al. is more climastrology junk and, CostCo, your attempts to defend it are the total failure which attempts to defend such junk always are.
Richard
Chad Jessup says:
December 3, 2012 at 8:36 pm
I am not surprised the Greenland ice sheet has decreased lately, because a few years ago, before finding Anthony’s informative blog, I stumbled across a website that detailed the temperature of the Gulf Stream (which flows to Greenland), and it showed that its SST has been increasing…..Shouldn’t there also be a SST site for the warm waters flowing north along the eastern Asian continent?
_____________________________________–
Yes it is called the NAO or North Atlantic Oscillation.
My quickest to find link is Vukcevic since he has done a lot of work with the available data.
Richard S Courtney does an excellent job of summarizing but I have one quibble. The paper is not climastrologic junk. Every Inquiry has value.
“If I find 10,000 ways something won’t work, I haven’t failed. I am not discouraged, because every wrong attempt discarded is another step forward”.
Thomas A. Edison
richardscourtney says: “The paper is not a “landmark”: it is a report of an expensive failure.”
I have this feeling you could be neck deep in water and you would say, “See, you guys are all wrong, my head is quite dry!” You know, you _could_ follow Anthony’s example, and make reasoned comments. Which I believe the CostCo and the “normal suspects” have tried to do.
You say that oeman50 succinctly stated, “When I saw the errors: “….–142 ± 49, +14 ± 43, –65 ± 26, and –20 ± 14 gigatonnes year−1….” it blew my mind. How do you draw meaningful conclusions when the errors are that large?”
Well, let’s see. If those are 1 sigma std errors, in Greenland the ice loss has a 2/3 chance of being between about -100 and -200 Gt/y and a 1/20 chance of being between about -50 and -250. That’s something I didnt know before. The important thing is that it is probably not zero, that would be about 1/100 chance.
For the Antarctic data, the -65 and the -20 are significantly different from 0, eye balling it at less than 1/20 and less than 1/8 chances, respectively. The only figure that is not really different from zero is the +14, a sad thing for people who would like to see the Antarctic cooling.
So it may be expensive. But a failure? No.
“richardscourtney says: The paper is “a landmark Science-paper”?! Really?”
Absolutely, as it showed definitely that the three satellite-based techniques measure the same thing.
“The paper reports that additional work costing a fortune failed to provide the measurement improvement it was intended to obtain so the paper calls for another fortune to be spent on giving them another attempt at the improvement. The paper is not a “landmark”: it is a report of an expensive failure. ”
Nope. It verified that the three techniques measure the same thing and reduced the errors. With current and planned satellites the accuracy can be increased much further in the future. Before this it was not even known whether Antarctica was in balance or not!
“Hence, good papers never have dozens of co-authors.”
That’s not true either as much of top science today is necessarily done in large research groups. See CERN, The Human Genome Project etc.
Questions related to sea-level retrieval from altimetry are not relevant here and the TRF-uncertainty is an order of magnitude too small to really matter in ice sheet observations.
Edward de Bono referred to this tendency as “The intelligence trap,” in his book, I Am Right, You Are Wrong. Here’s a google-search URL that leads to fuller discussions of the topic.
http://www.google.com/search?client=safari&rls=en&q=“The+intelligence+trap”+%22edward+de+Bono%22&oe=UTF-8&hl=en&spell=1
izen says:
December 4, 2012 at 3:19 am
@- E.M.Smith
….I still regard rejecting as you do all the research in the last sixty decades on AGW as motivated by issues other than scientific insight. The comment is a means of getting a fat paycheck perhaps is projection and reveals a fear that dealing with the thermodynamic consequences of rising CO2 might impact the fat paycheck the fossil fuel industry gets.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
The man’s semi-retired as I am so no fat pay checks for us from Big Oil or any other corporation for that matter. Same goes for Anthony Watts and many others who comment here.
The only fear is fear of dunderhead politicians and activists hellbent on completely killing off the USA, the EU, Australia and Canada and a large portion of the world population while they are at it.
The FACTS say that Global Governance is the actual motive with the World Bank handling the finances and economics (see SAPs for the Banks method of dictating to governments ) not the “thermodynamic consequences of rising CO2”
While the World Bank is screaming at the top of its lungs about the fairy tale of a 4 degree warming in their report Turn Down the Heat: Why a 4°C Warmer World Must be Avoided and Sound Bites from World Bank President Kim: “A 4-degree warmer world can, and must be, avoided” play in all the media. We only have to look at the actual reality around us to see the direction politicians are taking us.
The US Trade Deficit took a major nose dive when Globalist Pascal Lamy’s beloved World TRADE Organization came into being in 1995.
That Growing U.S. trade deficit with China cost more than 2.7 million jobs between 2001 and 2011
World Resources Institute identifies 1200 coal plants in planning across 59 countries, with about three-quarters in China and India
So how are these countries paying for these coal plants?
By the World Bank lending money for building coal fired plants. The amount lent soared 40-fold over the last five years from 100 million in 2005 to $4270 million in 2010.
SO where does the money lent come from? The United States has subscribed $31.96 billion giving it the largest single vote (16.52%) of any member country. Also in the USA Coal’s not dying — it’s just getting shipped abroad. along with out tax dollars and our jobs.
The results of this shift in manufacturing from clean air regulating countries like the USA to third world countries can be seen in the pie chart Record high for global carbon emissions – China is the leader WUWT link
The devastation to the environment that you Faux Activists cry crocodile tears about has been devastating.
photo 1 Lasengmiao Power Plant
photo 2 A man collects dead fish in Donghu lake, where officials say an estimated 30,000kg of fish have been killed
photo 3 cyclists in China wearing masks
photo 4 Beijing pollution
You Don’t Realize How Bad Pollution In China Is Until You Compare It To The US
It is using first world tax payer wealth to bootstrap third world countries into corporate slavery in MHO. A method used so corporations do not have to pay the tax payer does. It is an old and on going method used to fatten the bottom line. Santa’s Workshop: Inside China’s Slave Labour Toy Factories
Good Grief Democrat Dick Durbin, the Senate Majority leader stated outright “And the banks — hard to believe in a time when we’re facing a banking crisis that many of the banks created — are still the most powerful lobby on Capitol Hill. And they frankly own the place.” The Dog and Pony show about CAGW is to provide an excuse to the masses as to why the politicians are telling their citizens – bend over the banks and corporations want to rape you again. We know it is going to hurt but “It is for the CHILDREN” “It is for the ENVIRONMENT” When Obama has the Champion Job exporter Jeffrey Immelt CEO of GE (yes the GE that pays no corporate taxes) as his Jobs Council czar you do not know whether to laugh or cry.
Oh, and no one is bothering to pay attention to this graph which says all the models AND conjectures behind the models is crap.
So don’t you DARE imply we are corporate stooges when it is the CAGW scientist/activists who are the actual traitors to the environment and the human race! It is called projection and activists do it regularly hoping the masses will not see THEY are the traitors and the ones engaging in the actions they project on skeptics.
Greenland is losing mass 5 times faster than only 20 years ago. This we know.
[you need to put in something that shows “we know” because without it this is a content free post. Such posts are often seen as trolling and nobody, not even you, likes that, or did you leave the /sarc off?. . . mod]
CostCo says – “….there are zero tide-gauges in the open ocean, where incidentally much of the largest sea-level changes have happened.”
1. Define “open ocean”. I was sailing approximately 30 miles off the northern NJ coast on autopilot right at sunset when I quickly had to turn it off and manually steer hard to avoid hitting a……tide gauge.
2. Are you suggesting that dramatic sea-level changes are generally localized in the open ocean based on suggested CAGW (not considering moon phase, rogue waves/storms, Bay of Fundy events, etc)?
If so then we can agree that icemelt from Greenland or Antactica is not a problem for coastal areas but only the open ocean and therefore requires no action by coastal residents.
CostCo says:
December 4, 2012 at 1:04 am
>>
“P. Solar says: Gravity data from GRACE does not show ice loss , it shows gravity changes.”
Yes, and the very cool thing demonstrated in Shepherd et. al. is that a very snowy year on East Antarctic coast is visible in both gravity and altimetry measurements, as well as the precipitation model. The same signal is visible in these independent datasets, which increses the confidence in the results a great deal. If there was only GRACE or only altimetry, we could not be as confident about the result as we are now.
So, the acceleration of the Greenlandic mass-loss is a verified scientific fact, not empty speculation.
>>
Why do you pretend to reply to my comment without replying ?
You take one sentence out of my comment out of context and ignore the whole point I made. We’re not discussing “one snowy year” , we’re concerned with long term drift and calibration.
The fact that such a short term signal can be seen in various records IN NO WAY increases the confidence we can have in the individual drifts in calibration of any of the missions.
This repeats the basic deception of Sherpherd et al . Not only are you ignoring the point I made whilst pretending to reply to my post, you are propagating the deception by suggesting “the cool thing” in Shepherd et al increases the confidence we can have in the result.
The result of this paper was not the detection of your “one snowy year”, it was the alleged long term changes in ice thickness. That is totally dependant on long term stability of the satellite calibrations and models of the underlying movements in the bedrock.
The fact that you try to completely ignore my point and reply by pointing to the very short term variations I said were not relevant, shows you understand this clearly and are trying, like the paper, to deceive the reader.
Thank you for making your position clear.
Gail Combes says: The FACTS say that Global Governance is the actual motive with the World Bank handling the finances and economics (see SAPs for the Banks method of dictating to governments ) not the “thermodynamic consequences of rising CO2″
==========
When I read that the World Bank was to be entrusted with managing the ‘green fund’ and that before they’ve even agreed to have one, they want to claim U.N. diplomatic immunity from prosecution, it all suddenly started to make sense.
The generation of ‘useful idiots’ currently out to save the planet have, for the most part been duped.
If our grand children despise us it will not be for wrecking the climate, it will be for condemning the into economic slavery.
“P. Solar says: The fact that such a short term signal can be seen in various records IN NO WAY increases the confidence we can have in the individual drifts in calibration of any of the missions.”
Sorry, what “drifts” are you talking about exactly?
Rob Dawg:
At December 4, 2012 at 4:59 am you say to me in your reply to my post at December 4, 2012 at 3:40 am
Yes, I agree.
In my post you are answering I said
But that does not stop the work reported by Shepherd et al. from being the expensive failure which it is.
And the responses to my post from CostCo and trafamadore show just how bad a piece of junk the paper is: if they had worthy defences of the work reported by Shepherd et al. then they would have provided them.
Richard
Satellite trends versus tide gaude trends:
The “explaination” of higher satellite trends with trade winds leading to higher sea level rises in open sea is not valid.
For an increase, there have to be ADDITIONAL trade winds to form that deviation. and those ADDITIONAL trade winds would have had to be sustained for many years and just have started in the year when the satellite record started.
But thats not all, additional trade winds would have to blow from coast to open sea anywhere in the world and not from east to west.
It is much more safe to assume, that satellite trends are inflated and tide gauge data are correct.
“richardscourtney says: if they had worthy defences of the work reported by Shepherd et al. then they would have provided them.”
Heh heh. There are tons of worthy evidence provided in the paper itself, the supplementary material and the references. You folks have not even provided proper critique so far.
CostCo says: Greenland is losing mass 5 times faster than only 20 years ago.
0 x 5 = 0
Nothing to worry about.
CostCo:
Your post at December 4, 2012 at 11:09 am says in total
Ah! So you claim to know of some defences of the failure of the project reported in the paper, but you don’t say what they are.
Quad Erat Demonstrandum
Richard
CostCo says: “Sorry, what “drifts” are you talking about exactly?”
Drift as in over time equipment gets further away from calibration. Which can induce unknown quantity of error into equipment.
Ever seen an elevator stop 1/4″ to 2″ above or below the floor it is stopping on? That would be one such example of Drift.
To get more into Drift issues, there can be Drift in both the equipment, the calibration system for said equipment, and even drift in the human using the calibration system.
Antarctica nothing to see, satellite sea level trends inflated, the only “meat” appears to be in the Greenland data.
Berkely Earth shows Greenland temperature just rising a little bit above 1940s..
http://berkeleyearth.lbl.gov/regions/greenland
The little rise of about 0.6 degrees in 70 years is way below arctic trends expected by climate models, and additionally, BE doesn’t correct for UHI and most of all, the increase is highly correlated with AMO, i.e. mostly natural.
http://upload.wikimedia.org/wikipedia/commons/thumb/1/1b/Amo_timeseries_1856-present.svg/300px-Amo_timeseries_1856-present.svg.png
Dave Wendt says:
December 3, 2012 at 5:07 pm
Many thanks for your comment. Doesn’t sound accurate at the 0.1mm level does it? The problem with satellites is that they take time to go round the earth. If the SLP has changed when you fly past your start point 90 minutes later how do you correct for the IB? The satellites are measuring discrete altitude points in a continuously changing SLP field. Sounds very messy to my relatively stunted mathematical brain. Oh, and wind heaps up the water as well. How do they correct for the effect of wind. Indeed, how do they simultaneously measure the wind at the time they take the altitude measurement?
BTW, “E Pluribus Unum” over the globe – I’m not signing for that.
And Thank you WUWT for showing up another major problem with GRACE, which is also used for measuring aquifer levels and soil moisture content, in support of radical water sustainablility policies.
Here is an interesting PDF on the complexity of ground water fluctuations measured in over 2,000 observation wells in Hungary, at varying depths down to 1,000 meters. The deeper wells sometimes fluctuate faster than the shallow wells, without greater ground permeability to explain it. Don’t let them lob up a couple of satellites and claim the science is settled about Earth’s water tables.
http://itia.ntua.gr/hsj/redbooks/156/hysj_156_01_0345.pdf
http://www.nasa.gov/mission_pages/Grace/multimedia/chart20121129.html
from
http://www.nasa.gov/mission_pages/Grace/news/grace20121129.html
Caption on graph indicates “IJ05_R2 + W12a averaged” , so it appears they did not like the newer, more accurate GAIA adjustment and fudged it by taking the average to blend back in half of the older defective W12a model.
Some more detail on the paper and some excerpted graphs here:
http://www.thegwpf.org/doug-hoffman-ice-surveys-finds-slower-ice-sheet-melting/
“Darren Potter says: CostCo says: “Sorry, what “drifts” are you talking about exactly?”
Drift as in over time equipment gets further away from calibration. Which can induce unknown quantity of error into equipment.”
Right, so what kind of drifts are making the results suspect? TRF is not nearly big enough to change anything for altimetry and for SAR the influence is nil. Mind you that here long time-series were compared and the results matched, so are you proposing that the independent techniques are suffering from some weird drifts that somehow correlate over ling time-periods to make the results match?
“Manfred says: Antarctica nothing to see, satellite sea level trends inflated, the only “meat” appears to be in the Greenland data.
Berkely Earth shows Greenland temperature just rising a little bit above 1940s..”
What do the summer-temperatures say? In addition to warming above sea-level the waters around Greenland have warmed up, which ablates marine-terminating glaciers a lot from below.
CostCo says: “Right, so what kind of drifts are making the results suspect?”
The kinds of Drift that forced Shepherd et al to “ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass” in hopes of getting past the inaccuracies of each.
The kinds of Drift which causes error ranges larger than the data, and they don’t know to correct for or have a way to correct for.
The kinds of Drift that has NASA admitting to “‘spurious’ errors in current satellite based sea level and ice altimetry”.
The kinds of Drift which has JPL saying they need another space platform.
The kinds of Drift that has you trying to defend the indefensible. 😉
CostCo says: “What do the summer-temperatures say?”
You tell us. But back it up with links, not just claims of 5 times greater.
Then justify to us why we should only listen to what summer-temperatures say.
Zeke says: “Don’t let them lob up a couple of satellites and claim the science is settled about Earth’s water tables.”
Not to worry; that is no longer going to happen.
Two decades ago, some of us (myself being one) might have taking the proponents of Global Warming SCAM at their word. Mistakenly believing that AGW Climatologists/Scientists would never abuse their positions of Trust.
However, after seeing how AGW Climatologists/Scientists are willing to whore themselves for political purposes and funding – by adding bias to data, cherry picking data, lemon picking results, hiding facts counter to their claims (aka hide the decline), and lying (certain mann & peace prize comes to mind); those of us who mistakenly trusted them, will never trust them again.
The burden of absolute Proof now lies with them, as it should have been from day one.
It is greatly and profoundly unfortunate for the lives of the proposers of the ‘GRASP’ proposal in that it, the GRASP proposal, is factually flawed, i.e. a lie, and I posit the “scientists’ involved are like many others, now, hoisting a straw man argument to get NASA and NSF attention only in a futile attempt whose real purpose is to gain millions of US dollars and leverage the flawed perception of national prestige.
Otherwise, the GRASP proposal is an example of fraud and the proposers guilty of fraud and worse.
In their dreams!
Their worst nightmares will visit them, individually, in the course of the coming months. The Department of Treasury agencies move in mysterious ways, but now that the election is behind us the accountants are focused once again on the real value of currency and taxes owed.
Hay. They brought this on themselves. 🙂
About that Shepherd et al paper.
“nicht sogar falsch.” Prof. Wolfgang Ernst Pauli.
Translation: Not even wrong.
CostCo says:
December 4, 2012 at 2:15 pm
What do the summer-temperatures say? In addition to warming above sea-level the waters around Greenland have warmed up, which ablates marine-terminating glaciers a lot from below.
———————————–
Greenland is doing exactly what is expected at current AMO.
Greenland ice sheet melt from Chylek 2007 as reported by Akasofu who states: “present changes of the Greenland ice sheet are smaller than changes observed during the 1920– 1940
http://www.appinsys.com/globalwarming/RS_Greenland_files/image016.jpg
http://www.appinsys.com/globalwarming/RS_Greenland.htm
@Izen:
To get a “Global Average Temperature” one must average. Doesn’t matter if you put it in your comment or not. That folks assert, regularly, that they can get fractional degree (down at 1/100 C range) precision via said averaging reducing the variation in the data is simply a fact. That’s why the data are shown to 1/10 and 1/100 C precision (that is “False Precision” due to systematic error being treated as random error).
Doesn’t matter if you know it, put it in your comment, or not. That’s what is done to the data, and it is an error.
You then go on to present an emphatic overstated falsehood about me, and then react to it. Nice “Straw Man” but really a silly debate tactic. One I don’t accept.
First off, I don’t “reject…all the research in the last sixty decades”. As that’s 600 years, and I don’t think they were doing AGW Scare Grants in the 1400s… But assuming you meant 60 years or 6 decades: In 1940 they were not doing AGW Scare Grants either, and in the 1960s and ’70s it was New Ice Age Scare time. ( I lived through it…) I accept a great deal of the research from the last 600, or even 60 years. Just not the AGW Scare part of it.
As to why I reject the AGW Scare part of it, well, not only all of the stuff on WUWT, but all of the stuff about climate on my own blog. Far too much to put in one comment. Hundreds (thousands?) of pages of it. Only one small part of it is the $Millions hauled in by Al Gore and Mann (nice grants he gets, no?) and all the other flood of money from various NGOs and the UN.
Oh, and that $100 Billion the UN wants as “Carbon Sin Tax”, I’m sure that doesn’t bias their desires one bit. They would be happy to take zero dollars and just fix the carbon “problem”… /sarcoff>;
So that’s just one tiny bit of why I think AGW “science” is deeply flawed. But some of it is reasonably well done. (Though that part tends not to find much warming or much damage from it, if it did happen.)
Now what I do think needs to be “tossed out” is the thoroughly corrupted data sets. Things like the product of GIStemp. ( If you don’t know, I have it running in my office and have looked at ever line of the code. It’s pretty poor. Though the guy they hired to do the Python bit did a nice job of writing the code, but I think it does something that is scientifically silly. – Step 2 IIRC.)
So I’ve sunk a few years of my life into personally checking many of those claims about “the end of life as we know it” and “temperatures known to 1/100 C” and found them terribly wanting. Often (largely?) due to one of: Instrumental data biased, worse corrections, wrong way ‘corrections’, horrid splice artifacts, biased baselines, confounding long term cyclical changes with ‘trend’, and outright scientific malfeasance. (UEA lost their data? REALLY? In High School that would get you an F and taking the class over…) So yes, I think the output product of UEA, NOAA/NCDC, and NASA/ GISS all need to be ’round filed’ and we need to go back to the raw data sheets (IF they can still find real data) and start over. Recognize that data recorded to 1 F (and with no way to tell random error from systematic error) can’t be made any more accurate than 1 F by averaging it together (GIStemp keeps temperatures AS temperatures until the last step when it makes ‘grid box anomalies’ so that whole argument about ‘it is all done with anomalies’ is just bogus).
One Simple Example: The Stevenson Screens were shown by A. Watts et. al. to have a warming bias. This is a systematic error. The paint changes as they age and the temperatures rise. Peterson, of NOAA/ NCDC is on film saying that when they rolled out the MMTS to replace them, they showed a ‘cooling bias’ and it was ‘corrected’. Except that it wasn’t a cooling bias. It was that the Stevenson Screens had warmed over the years of paint fading. So instead of ‘correcting’ a cooling bias they were locking in a systematic warm error.
No amount of averaging or anomaly processing can remove that systematic error bias from the data and it simply is NOT going to be accurate to any finer degree than 1 F (US data and much of the older world data was collected in F, so that’s the raw data precision).
Now we find the satellite data has similar ‘datum’ issues and is also filled with a systematic error. To state that is not to ‘reject all science from the last 60 decades’, or even the last 60 years. It is to reject the data as deeply flawed for saying anything useful about precision as fine as mm.
Now look at the computer models that are so wrong (even compared to the wrongly over warm data we have) and it’s pretty clear they are broken too. We’ve fallen below their lowest band of prediction (or projection or hand waving or whatever new word of the day you pick this week…) and we’ve had a 16+ year standstill in the ‘warming’. (Golly, no instrument change splice artifact and things stop “warming’…) So it’s pretty darned clear that the models are useless for prediction.
Which makes basing policy on those predictions pretty dumb.
But you go on:
As I have no connection with the fossil fuel industry other than using their product, I really don’t care much about their paycheck. However, you ought to realize that Oil doesn’t fund the anti-AGW side much. It spends more money on the AGW folks. Why? Because they want to kill off the competition. Coal. Exxon uses CO2 for tertiary oil extraction and some years back was lamenting that they would soon have to purchase it. Gee, now if they could only get their competition, coal, to pay THEM to take away that nasty CO2 and “sequester it”…
And look at the total funding flowing to the AGW parade (measured in hundreds of millions) vs the skeptics (largely volunteer or occasionally getting small $1000 sized or smaller donations). Pretty clear where the money is at. Just measure Al Gores wallet… Oh, and check out the investments in “alternative energy companies” that got a chunk of ‘bail out money’ and then folded. Does the name Solyndra mean anything to you? Yeah. “Friends of Democrats” getting bailout money and subsidy money by the truckload.
If you “follow the money”, it’s very clearly about 100 : 1 on the “pro AGW” side and going to the politically connected. Even from the oil companies. (Coal not so much…)
That you subscribe to the canard of oil funding skeptics makes it pretty clear you’ve not actually looked at the money flows.
As to the ‘thermodynamic consequences of CO2″: Since they are substantially nil, I have no fear of what they would do to anything. We have existence proofs from all of past history that the planet can be in an ice age at 7000+ ppm and hotter than now at lower CO2. It just doesn’t have control of the thermostat. (Position of the continents, orbital mechanics, solar changes, and the occasional big BANG from space do… with water vapor being the dominant control / working fluid in the system).
So please, keep your innuendo and straw man smears to yourself. They have nothing to do with me or my beliefs, and even less to do with the reality of climate.
The reality of climate it that at present it is extraordinarily stable, but after 12,000 years of so of ‘reasonably warm’ we’re on the cusp of a decent into the next glacial. There’s an existence proof of no ‘tipping point’ to warmer (the Holocene Optimum that was about 2 C warmer than now) and one of a clear ‘tipping point’ to colder (that glacial we just had). Look at the temperature graph for the last 10,000 years and it’s a clear hump. We’re on the ‘lower lows and lower highs’ side of things. The LIA was colder than the prior cold period. This Modern Optimum is lower than the prior warm period ( Greenland ice core data). The only really good news is that it takes 100,000 years for the slide to cold to build up the full ice sheet, and there’s about a 1500 year cycle, so we could well be in the slide into the next ice age and not know it. Things change that slowly on the long fall, and cycle faster on the 1500 year range.
So, believe it or not, I desperately hope CO2 driven global warming is correct. It’s the only thing that can possibly prevent our entry into the next glacial period during the next 1000 to 2000 years. I’d like to burn every scrap of carbon fuel we can during that time. If we’re really really lucky, it will slow the decline. Unfortunately, there is no evidence that it will work, as we have those prior glacials with higher CO2.
Unfortunately, we live on a ‘water world’ and convection, evaporation, and condensation drive things. Not a trace gas of no importance to weather.
Oh, and sending $100 Billion to the UN, a few $100 Billion to “Friends of Congress” for investing in their
pocketscompanies, and more $100 Billions to owners of ‘carbon exchanges’ (like Al Gore and friends) will not change the climate either… which leaves me wondering why that’s what they keep proposing for the ‘fix’…Me? I’m going back to my self funded ‘research’ into climate data and not expecting to see even $10 from an “Oil Company”. ( I sometimes get donations at my blog. Last year I bought a ‘smoker’ and I’ve managed to get good at doing BBQ in it… Just to put some scale on the money thing… It’s measured in low 3 digits / year…) So when you go snarking about all the money on the skeptic side, well, it’s really a hoot…
Now to catch up the rest of the comments…
“Darren Potter says: CostCo says: “Right, so what kind of drifts are making the results suspect?”
The kinds of Drift that forced Shepherd et al to “ensemble of satellite altimetry, interferometry, and gravimetry data sets using common geographical regions, time intervals, and models of surface mass balance and glacial isostatic adjustment to estimate the mass” in hopes of getting past the inaccuracies of each.
The kinds of Drift which causes error ranges larger than the data, and they don’t know to correct for or have a way to correct for.
The kinds of Drift that has NASA admitting to “‘spurious’ errors in current satellite based sea level and ice altimetry”.
The kinds of Drift which has JPL saying they need another space platform.
The kinds of Drift that has you trying to defend the indefensible. ;)”
There are no unknown drifts that are “larger than the data” so your point is moot. We have three independent techniques that see the same thing, which increases the confidence in these results a lot. I’m willing to bet that satellites not used in this study, for example CryoSat-2, will corroborate these results. I think it’s fantastic that ice sheet monitoring has progressed so far it has given the remoteness and sizes of the continental ice sheets.
“Manfred says: Greenland is doing exactly what is expected at current AMO.”
Well is it really? Check this Nature-paper:
http://www.nature.com/ngeo/journal/vaop/ncurrent/full/ngeo1481.html
…where it is stated that:
“We show that many land-terminating glaciers underwent a more rapid retreat in the 1930s than in the 2000s, whereas marine-terminating glaciers retreated more rapidly during the recent warming.”
The marine-terminating glaciers have been retreating more rapidly today, possibly due to increased underwater melting. The marine-terminating glaciers are exactly the ones that are responsible for most of the ice-loss and the retreats of their calving fronts have caused them to flow faster, dumping more ice into the ocean. Got any evidence for arguing this is within “normal variability”?
‘E.M.Smith says: So, believe it or not, I desperately hope CO2 driven global warming is correct. It’s the only thing that can possibly prevent our entry into the next glacial period during the next 1000 to 2000 years. I’d like to burn every scrap of carbon fuel we can during that time. If we’re really really lucky, it will slow the decline. Unfortunately, there is no evidence that it will work, as we have those prior glacials with higher CO2.”
That’s a reckless attitude as you’re basically suggesting doing geoengineering of Earth with a compound that stays in the atmosphere for a very long time, i.e. a non-reversible experiment in human timescales. Using something that stays in the air for only a couple of years would be infinitely wiser as then it would be possible to withdraw the forcing quickly if something bad starts happening. For example, what will you do if it turns out that your increased atmospheric CO2 is going to trigger a new ice age through shutdown of the thermohaline circulation in North Atlantic? A hypothetical example but it demonstrates your approach to geoengineering is reckless.
Does that mean that the data series was regularly “recalibrated” so that each resultant “trend to date” maintained the desired 3.2 mm/yr gradient?
CostCo:
I see that at December 5, 2012 at 1:03 am you have abandoned the hopeless task of trying to defend the indefensible paper by Shepherd et al. and, instead, you try to scare-monger about Greenland ice loss. You write
So, you say, “The marine-terminating glaciers have been retreating more rapidly today, possibly due to increased underwater melting.”
Well, that is possible. Or it may possibly be due to the breath of dragons. Or it may be possibly due …
There is no more reason to be concerned at the present glacier retreat being predominantly “marine-terminating glaciers” than there was to be concerned that the previous glacier retreat was predominantly land-terminating glaciers. The Greenland ice continues to retreat at a rate which is trivial.
Simply, Manfred is right when he says, “Greenland is doing exactly what is expected at current AMO”; i.e. it is losing ice at a trivial rate.
Richard
“richardscourtney says: The Greenland ice continues to retreat at a rate which is trivial.”
Yes, but ice-loss is accelerating at a rate that is not trivial, i.e. five-fold in just 20 years. The ice-stream acceleration has been witnessed further and further north and there’s still room for more acceleration in the coming years. A millimeter per year in sea-level from Greenland only is not that far away if acceleration continues.
“richardscourtney says: I see that at December 5, 2012 at 1:03 am you have abandoned the hopeless task of trying to defend the indefensible paper by Shepherd et al. ”
Should I “defend” against the negligible TRF-error and Anthony erroneously chose to highlight on WUWT instead of the findings of this landmark paper? (where’s the redaction of that BTW?). Or do I also need to defend against the (non-existing) drifts-that-cannot-even-be-named that might derail the results? LOL I say.
But additional ice loss in September in the Arctic leads to .. MORE COOLING of the Arctic ocean through evaporation losses! (At latitudes north of 82 latitudes, there is NO extra absorption of solar energy when the sun is less than 5 degrees above the horizon. All but 5% of the solar energy is reflected from the water.
More Arctic evaporation (in August and September and October) leads to more snow in Europe and Russia and Siberia and China in October and November and December …..
(By the way, more Antarctic sea ice in September (at record levels this year) reflects more solar energy from latitudes 60 south and leads to … MORE COOLING! )
So, is this the tipping point starting the next ice age that you want?
CostCo:
At December 5, 2012 at 5:26 am you say
Yes, and I would be a millionaire if I had won the Lottery. Wake me in the unlikely event that there is as sign of a problem.
And I notice that at December 5, 2012 at 5:30 am you admit you have abandoned your attempts to defend the paper by Shepherd et al.. I remind that the failure of the project reported by that paper is the subject of this thread, and your attempts to discuss other things only add emphasis to your inability to defend that paper.
Richard
CostCo says: “There are no unknown drifts that are “larger than the data” so your point is moot.”
#1) With “unknown drifts” you can not make such a claim. They are “unknown”!
#2) Drifts when combined could be. Drift A < data, Drift B Data.
So sorry, the point about Drift is relevant. If you had technical knowledge you would have already known the issues of Drift (both known and unknown), and would not have needed to ask. I suggest you go read up on Instrumentation Calibration and Drift, then take a technical course dealing with both.
CostCo says: “We have three independent techniques that see the same thing, which increases the confidence in these results a lot.”
So you claim, but that is not what the report’s Table-1 shows. I really love it when somebody makes a claim like “increases the confidence in these results a lot”. Fits right in with Al Gore and Hansen’s arm waving Sky is Falling GW press releases.
CostCo says: “Yes, but ice-loss is accelerating at a rate that is not trivial, i.e. five-fold in just 20 years.”
Five times over 20 years. Five times trivial means little to nothing. Thus Alarmism.
And once again, nothing ties supposed ice-loss to claimed AGW (claimed man-induced Global Warming due to increases in CO2). Correlation does not imply causation. But claiming it does shows proponents of GW to be intelligence challenged.
And once again, even if ice-loss was tied to CO2, we are very near the ppm level at which CO2 can have maximum impact as Greenhouse Gas. Thus further increases would be “trivial”. 😉 http://www.randombio.com/temperatures6.png
Feel free to keep commenting, but you are just reaffirming that pro-pundits of alleged AGW lack facts, don’t understand scientific method (or science), are technically weak (using computer to post on internet don’t count), mistakenly use information holed like Swiss cheese, jump to conclusions, repeat AGW talking points without verifying, and attempt to sell AGW by mass propaganda.
“richardscourtney says: And I notice that at December 5, 2012 at 5:30 am you admit you have abandoned your attempts to defend the paper by Shepherd et al.”
State your criticism please.
“richardscourtney says: CostCo: Yes, but ice-loss is accelerating at a rate that is not trivial, i.e. five-fold in just 20 years. The ice-stream acceleration has been witnessed further and further north and there’s still room for more acceleration in the coming years. A millimeter per year in sea-level from Greenland only is not that far away if acceleration continues.
Yes, and I would be a millionaire if I had won the Lottery. Wake me in the unlikely event that there is as sign of a problem.”
How is this not a sign of a problem? Do you want to see an even larger and more rapid change, like the one that is happening to the Arctic sea ice volume?
No, we don’t want to see ice loss in the Arctic. More ice loss up there (past today’s 82 north limit at minimum sea ice extents) causes more cooling.
Oh – by the way. Why has ice loss increased/continued if the earth has not warmed the last 16 years?
CostCo:
At December 5, 2012 at 7:42 am you ask me concerning the trivial rate of ice loss on Greenland
Care to run that by me again?
You are claiming some kind of problem, not me. In the event that you can think of one then tell me what it is.
And having failed in your distraction about Greenland ice loss, you now attempt to change the subject to Arctic sea ice which one can hope will provide the benefits of its total loss (but it won’t).
Instead of attempting to distract attention from the egregious Shepherd et al. paper which is the subject of this thread, how about returning to the subject of this thread or – since you admit you can’t defend the paper – going away?
Richard
“Darren Potter says: So sorry, the point about Drift is relevant. If you had technical knowledge you would have already known the issues of Drift (both known and unknown), and would not have needed to ask. I suggest you go read up on Instrumentation Calibration and Drift, then take a technical course dealing with both.”
I have technical knowledge in the satellite and instrument domains and that’s why i’m asking what drifts you are talking about. Inventing unknown & undetectable drifts is not an “argument”.
“So you claim, but that is not what the report’s Table-1 shows. I really love it when somebody makes a claim like “increases the confidence in these results a lot”. Fits right in with Al Gore and Hansen’s arm waving Sky is Falling GW press releases.”
Absolutely it increases confidence since the methods are largely independent. Imagine if we only had GRACE, then pundits could forever claim that the GIA-adjustment is flawed and we still don’t know zilch. Now it’s clear what is going on in Greenland and the data on Antarctica is getting clearer too. Current and planned satellites will make monitoring ice sheet mass balance a routine operation in the future. Stay tuned.
“RACookPE1978 says: Oh – by the way. Why has ice loss increased/continued if the earth has not warmed the last 16 years?”
The Arctic has warmed up quite a bit in the last 16 years and so has Greenland including the sub-surface waters around it.
“richardscourtney says: how about returning to the subject of this thread ”
That’s fine, so what is your criticism? Hopefully something more substantial than unknowable phantom drifts..
You are wrong. Dead wrong.
Arctic sea ice (in the summer is ONLY between 82 north and 90 north (the pole). Arctic sea ice (in the winter) is located between 70 north and 90 north.
the ONLY Arctic temperatures going higher recently are 1200 – 1600 kilometer INLAND between 60 north and 65 north. And they are going up because the CO2 increase is increasing plant growth by 22% to 27% everywhere globally, and THAT albedo change is increasing sunlight absorption and increasing INLAND temperatures above the ever-darker, ever greener tundra and forests.
The Denmark DMI daily MEASURED arctic temperatures at 80 north have NOT risen since 1958. And, recent DMI summertime measurements are actually going down as CO2 levels increase.
“RACookPE1978 says: The Denmark DMI daily MEASURED arctic temperatures at 80 north have NOT risen since 1958. And, recent DMI summertime measurements are actually going down as CO2 levels increase.”
That may be but the area above 80N is just a small part of total area of the Arctic. I haven’t chaked what ECMWF uses for it’s definition of the “Arctic” but the trend is very clear:
http://www.ecmwf.int/products/forecasts/d/inspect/catalog/research/eraclim/timon/timon_ana_2D!2T!anom!Arctic!195701-201212!/
CostCo:
At December 5, 2012 at 8:52 am you ask me
I have several criticisms but as a start I suggest that you address the issue first raised by Billy Liar in his post at December 3, 2012 at 2:13 pm and cited by me in my post at December 4, 2012 at 3:40 am.
This issue alone condemns the method adopted by Shepherd et al. to the garbage bin for the reason explicitly sated in my post at December 4, 2012 at 3:40 am.
Billy Liar posted it. I cited it as an example. You have not addressed it.
Richard
Well, since the sea ice (at minimum extents) is ONLY found between 82 north and the pole, what the temperature might be 600 km, 1200 km, and 2000 km further south won’t affect the local sea ice melt rate. The Denmark measurements are the ONLY ones at the same latitude where the sea ice is. They are the only ones that matter. Annual averaged artic temperatures – when the ice is already frozen – don’t matter either: The ice has frozen, the sun is below the horizon, and the winter sea ice extents across the arctic are the same as are they always have been recently measured.
And, since the exposed water around the melting sea ice has a thermal capacity 1000 times the thermal capacity of the air blowing past the sea ice, the surface temperatures 1200 km further south – where Hansen’s GISS plots a single red “blob” in the middle of the Canadian tundra – won’t affect water temperatures nor sea ice melt rates.
You are wrong.
In defense of the paper, my hope is that the authors believe that they have accounted for the various instrumentation errors and biases. If the instrumentation error is random and normally distributed, then it would tend to cancel out over numerous measurements. The real problem is discovery and management of biases.
What I find fascinating about the discussion is when Greenland ice loss eventually starts decelerating, the Arctic ice cap starts recovering, and sea levels stop rising then we will have equal and opposite alarmist reaction to climate change (this time cooling) with a set of solutions that looks suspiciously like those needed to address warming.
This all looks like a negative feedback to me. Trenberth’s missing heat is making its way to the arctic ocean where it melts ice and is eventually radiated into space.
CostCo says: “I have technical knowledge in the satellite and instrument domains and that’s why i’m asking what drifts you are talking about. Inventing unknown & undetectable drifts is not an “argument”.”
This coming from a person who makes vague, arm waving, unreferenced, or undefined statements like the following:
“Greenland is losing mass a lot faster than only 20 years ago and some areas in Antarctica are changing too.”
“Yes, but ice-loss is accelerating at a rate that is not trivial, i.e. five-fold in just 20 years”
“Heck, in some places and at some times the ice sheet surface is dropping 10+ meters per year!”
“I seriously doubt that it would change the GRACE-results either.”
“Subsidence of bedrock or what? Anyway, the surface velocity of the ice is known, which can be used to infer what is going on.”
Now assuming you really do have technical knowledge, then you tipped your hand to being dishonest. By denying there are unknown / undetectable drifts that cause inaccuracy in the satellites and instruments aboard the satellites, despite there being conflicting results coming from data collected from different platforms. You would also have to know there had been unknown calibration problems between satellites calibrated on the ground and then using those satellites internal temperatures for recalibration once in space. Along with unknown problems such as correcting for diurnal cycle drifts. Then there has been drift induced errors into satellites’ instruments/data collected because of human error in failing to take into consideration orbital changes. And you would have heard of drift errors due to non-linear calibration problems in at least one satellite used by AGWers. Yes, those drifts are known now, but those drifts/errors were originally unknowns or undetected.
A dishonesty that seems to permeate throughout the AGW community:
http://wattsupwiththat.com/2010/10/04/an-over-the-top-view-of-satellite-sensor-failure/
So there you go either you don’t know what your talking about and unknown & undetectable drifts is valid issue, (backed by errors in data as reported), or you are being dishonest in denying such drifts.
That item should be added to Anthony’s “Did You Know . . . ? series.
“Now assuming you really do have technical knowledge, then you tipped your hand to being dishonest. By denying there are unknown / undetectable drifts that cause inaccuracy in the satellites and instruments aboard the satellites, despite there being conflicting results coming from data collected from different platforms. You would also have to know there had been unknown calibration problems between satellites calibrated on the ground and then using those satellites internal temperatures for recalibration once in space. Along with unknown problems such as correcting for diurnal cycle drifts. Then there has been drift induced errors into satellites’ instruments/data collected because of human error in failing to take into consideration orbital changes. And you would have heard of drift errors due to non-linear calibration problems in at least one satellite used by AGWers. Yes, those drifts are known now, but those drifts/errors were originally unknowns or undetected.”
Error related to calibration are taken into account and they contribute to the error-bars. Satellite and inter-satellite calibration is a constant ongoing effort and large drifts will be caught. Basically you’re insinuating that the glaciological community as a whole does not know how to assess errors and neither does Nature/Science etc. Besides, considering the accuracy needed for sea-level estimation, the comparatively large changes in ice sheet elevation are much easier to detect.
“RobertInAz says: What I find fascinating about the discussion is when Greenland ice loss eventually starts decelerating, the Arctic ice cap starts recovering, and sea levels stop rising then we will have equal and opposite alarmist reaction to climate change (this time cooling) with a set of solutions that looks suspiciously like those needed to address warming.”
Considering the positive feedbacks associated with the loss of ice- and snow-cover during summer, it quite possible that won’t happen anytime soon. The sea ice volume is showing no signs of recovery.
“richardscourtney says: I have several criticisms but as a start I suggest that you address the issue first raised by Billy Liar in his post at December 3, 2012 at 2:13 pm and cited by me in my post at December 4, 2012 at 3:40 am.”
You must mean this: “Can somebody tell me how these satellite altimeters compensate for the inverse barometer effect where there are no measurements of the surface pressure?
In order to get accurate sea levels you have to have accurate simultaneous atmospheric pressure measurements.”
Several things come to mind:
1. I’m not aware of atmospheric-pressure trends over 20 years that could cause a bias in the barometric correction – are you? Also, are you postulating that there are localised atmospheric pressure anomalies over some areas (for example the Amundsen Sea) that causes an uncorrected bias that is the order of tens of meters? Does not sound credible to me.
2. In any case the barometric correction is relevant in the estimation of sea-level where the needed accuracy is 1-2 orders of magnitude higher than over ice sheets. If you believe that this correction is large enough to cause large uncertainties in Ice Sheet elevation-change estimates, please post some numbers.
3. Thanks to atmospheric reanalysis and planetary models the surface pressure is not “unknown” anywhere on the planet during the satellite era. Of course there are related uncertainties but please show that the errors resulting from this are relevant when retrieving relative ice sheet elevations.
4. The barometric correction is an issue in altimetry, while gravity and SAR-measurements are not affected by it. As discussed, the other independent techniques see the same signal.
CostCo:
Thankyou for your post addressed to me at December 6, 2012 at 2:05 am. This is my reply and it addresses each of your numbered points in turn.
You say and ask
Barometric pressure varies with temperature, and temperature has varied.
Sea level varies with barometric pressure.
Nobody knows how this has affected “a bias in barometric correction”, and that is my point.
Local temperature variations differ from the global variation.
Sea level rises one centimeter per millibar drop in air pressure. Strong storms can have 50 millibar drop in pressure, causing a 50 cm rise in water levels on top of levels due to wind and tides. Hence, the local maximum error from barometric pressure variation is of the order of 50 cm. The press release of the paper says
Hence, the possible local effect of barometric pressure variation on sea level is 5 times the magnitude of the claimed contribution to global sea level from Greenland ice loss over the measured period. Assume actual local effects are a tenth of the maximum, then barometric pressure variations are a significant effect on local sea level.
You say
Ice sheet measurements are not relevant. The barometric effect is on sea level. However, the sea level determinations are used to “reconcile” with ice sheet measurements.
You say
Models are assumptions and not measurements. Nobody can know the errors introduced by the assumptions. The issue is sea level determination errors. Again, variations in barometric pressure affect sea level and not ice elevation. However, the sea level determinations are used to “reconcile” with ice sheet measurements.
You say
The issue is variation in sea level induced by varying barometric pressure. Altimetry is not relevant. And you have “explained” nothing. Instead, and as is your usual practice, you have presented arm-waving assertions, irrelevancies and assumptions. The “other techniques” are not “independent”: they each utilise the same assumptions. (It seems that “independent” has a strange meaning for warmunists who claim, for example, that tree ring analyses of the same trees are “independent”.)
The effects of barometric pressure changes are not known. And those effects could be the cause of most of the apparent increase to sea level distant from shores which is responsible for most of the claimed increase to sea level change. If so, then the system reported by Shepherd et al. is useless as an indicator of sea level rise near shores because a change to distribution of barometric pressure changes would have severe effects on sea level near shores. Indeed, such an effect on sea level at shores would be much more rapid (although not permanent) than ice loss.
Also, without knowledge of the barometric effects on sea level any claim that the sea level determinations “reconcile” with ice changes are speculative at best and probably indicate confirmation bias.
Richard
“richardscourtney says: Ice sheet measurements are not relevant. ”
You seem to have a fundamental misunderstanding about what was measured and estimated in Shepherd et. al. This study did not measure sea-level anywhere! Instead, Ice Sheet mass-balance was estimated over a period of 20 years. The mass-gain/loss in the Ice Sheets was converted to sea-level-equivalent with a simple formula.
Do you have any criticism on the scientific content of Shepherd et. al., i.e. on Ice Sheet mass-balance estimation using the three (largely) independent spaceborne techniques?
CostCo:
re your post at December 6, 2012 at 7:27 am.
Firstly, let me apologise for an error. As you infer, I did misread the above article in that I (mis)understood the JPL work to have been incorporated in the paper by Shepherd et al.
Mea culpa
My error does make my answers to your points misplaced (although true with respect to the JPL work). And, therefore, several of my answers to your points are inappropriate. Please understand that this was a genuine mistake and not an attempt to avoid your points nor to misrepresent them. I apologise for any offence my error has caused.
I reply to your specific question asking
I do not agree that the methods are “largely independent”. This is one of the issues which my error did not distort. The techniques each use the same assumptions and there is no available independent calibration. Hence, the techniques have unknown – but probably similar – errors (the “drift” issue being one such unquantifiable error).
And this raises the ‘TRF issue’. Without a static terrestrial reference the ‘differences’ in ice height could be artifacts of the variation in TRF and there is no way to determine to what degree this is the case.
Richard
Richard: As explained by me in this thread, the TRF-error is way too small to cause any issues in ice sheet elevation measurements. It is relevant for sea-level where millimetric accuracy and stability is required over long periods of time.
The techniques are really “largely independent” bacause the measurement-principles are so different (measuring gravity, measuring height, measuring surface-movement). “Drifts” are measured continuously in satellite cal&val activities so the existence of them is known. This is why the existence of the sub-millimeter TRF-error is known. I cannot comment on gravity but I fail to see how SAR or altimetry could have unknown large drifts.
There is another dimension to establishing a reliable TRF that must not be overlooked – the undulation of the geoid we call Earth. Its shape is affected by internal phenomena (that we attempt to measure as gravimetrics) resulting in minor flexing of the crust that (due to elasticity of material) not always results in earthquakes. The wide varieties of factors like erosion deposits, variations in barometric pressure and salinity at any point on any given day all contribute to the enormous complexity of any valid mathematical solution. Has anyone presented good data showing that the current gravimetric method used by satellites actually has a resolution below centimeters ? This takes us back to one of the points in this article – that we have nothing without a good baseline, making arguments over millimeters sound truly absurd.
References:
http://kartoweb.itc.nl/geometrics/reference%20surfaces/body.htm
http://en.wikipedia.org/wiki/Geoid
http://en.wikipedia.org/wiki/Mantle_%28geology%29