A climate science bombshell: 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.
People send me stuff. Today it is a PowerPoint presentation from NASA JPL that 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:
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:
In a nutshell, JPL is saying we don’t have an accurate reference point, and therefore the data from these previous missions likely has TRF uncertainties embedded:
The TRF underlies all Measurement of the Earth
Without that stable Terrestrial Reference Frame that puts the precision of the baseline measurements well below the noise in the data, 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.
PowerPoint here: Poland 2012 – P09 Bar-Sever PR51 (PDF)
More info: http://ccar.colorado.edu/~nerem/EV-2_GRASP-final.pdf
UPDATE: Here’s an estimate of impacts:
Source: http://www.gps.gov/governance/advisory/meetings/2011-06/bar-sever.pdf
I wonder how large the error is compared to the effect being measured?
The comparison chart suggests it to be relatively small, but what if the error exceeds the effects?
I never believed it in the first place. The pretence that it could possibly be so accurate was always bogus.
Whenever you look at the post-glacial sea-level record, it is easy to see the rapid rise (punctuated by the Younger Dryas) which then peaked broadly several thousand years ago. The last thousand years or so appear to be on a slight decline. What with isostatic rebound etc. one would expect no sea-level rise if not a continuing fall with time.
We are heading back into a glacial epoch, after all…
So assuming this goes into place, don’t we have the problem of how to splice the new instrumental data on to the existing? Which means we will need some kind of correction to normalize the earlier records to the new reference. Or do we give up on an aggregated instrumental record and just say the satellite record for sea-level begins in 2013 (or whenever)?
So, we’ve been getting sea level data accurate to 0.02mm +/- 2m?
[/nonsense]
I should hope a next generation satellite is greatly improved over existing systems.We do need to get a handle on getting good measurements of the Earth’s features. Let’s hope GRASP exceeds its reach.
I have had a lot of experience with various types of space based measurements and we have always been aware of how many errors can enter the systems which ALWAYS make the data estimates. For instance, the ephemeris for the spacecraft always has some degrees of uncertainties so measurements taken from the spacecraft that depend upon time delay of arrival (and they almost do except for imagery) will be off at least somewhat. The errors are never consistent so you cannot just apply a correction factor. Other errors are occasioned because we don’t understand the geospatial aspects of the surface of the earth since the earth really isn’t round and the various kinds of relief on the surface also affect measurements as do different types of ground cover. There are many, many other factors entering into the process, none of which can be constrained.
Given all of that while we might get closer to accuracy, it can never be truly as accurate as ground based measurements. GPS is only as accurate as it because we use multiple spacecraft simultaneously. None of the data birds have that kind of multiple, overlapping measurements.
Cheers,
John
@ Alan Watt 12:42 pm
The answer one chooses depends on one’s geo-politics.
Measured with a micrometer, marked with a piece of chalk, and cut with a gas torch.
I don’t like that “3-year lifetime” thing. I realize it is an expectations game, short the useful lifetime up front and later brag about it exceeding its plan later. But this has got to stop. Taxpayers should take note of these never-ending expenditures and demand the heads of those signing off on them.
Additionally, it introduces extra variables into the long term dataset. In 3 years another bird needs to be launched which will be in a slightly different orbit and which will have different equipment, then we will stitch together their data and compare them without any regard for possible variation, much like we do now with our 30+ so-called pristine satellite record.
Whoa!
Quote:
Reinterpret satellite altimetry and tide gauge records to determine global mean sea level rise relative to the GRASP-based TRF – how sea level accelerating
Reinterpret satellite ICESat and GRACE data records to determine ice mass loss relative to the GRASP-based TRF – how is ice mass loss accelerating
Shouldn’t the be “reinterpreting” in order to see if global mean sea level either rising or falling and ice mass is either rising or falling?
Just wondering.
Still in the end… it’s only the sea level relative to land levels that are important and that is by far best measured by tide gauges on the ground. After calibration, GRASP could claim the oceans are rising at 1 meter per year and it wouldn’t mean squat. If tide gauges show 1.5mm/yr, it will still be the number that counts.
Stuart says:
October 30, 2012 at 12:53 pm
@ Alan Watt 12:42 pm
The answer one chooses depends on one’s geo-politics.
___________________
If past is prologue, the warmistas have nothing to worry about.
NASA’s James Hansen is on the job.
Anthony:
You say
I have always said I think both the tide gauge data and space based data lack adequate accuracy and lack adequate precision. And, sadly, I am not convinced that the additional satellite will correct this problem because of the rates and the changes in surface heights relative to sea level across the planet.
Richard
REPLY: You have to start somewhere and this is a good place to start to make sure the previous work is properly referenced. All measurement systems evolve. – Anthony
Seems Nils-Axel Morner may be correct.
http://www.21stcenturysciencetech.com/Articles_2011/Winter-2010/Morner.pdf
“This promises to rewrite what we know about sea level rise and acceleration, ice extent and ice volume loss measured from space.”
No, it promises to provide an excuse for rewriting what, inconveniently, aint happening.
Great comment from John Stover (12.50).
I can understand that radio telemetry/altimetry is inaccurate for transmittal reasons. What I cannot understand is how they can then ‘work’ back to a supposed accuracy of 1/10s of mm per year on a moving irregular surface! Sorry, but it just doesn’t compute……..
To my mind – it would be like estimating the surface area of a the leaves on a large tree from a mile away, with a stiff wind blowing! (at thats just in the summer!)
Reference RobUK above, there is also this PDF http://www.21stcenturysciencetech.com/Articles_2011/Winter-2010/Morner.pdf
In which Dr. Nils-Axel Mörner actually states:
“Now, back to satellite altimetry, which shows the water, not
just the coasts, but in the whole of the ocean. And you measure
it by satellite. From 1992 to 2002, [the graph of the sea level]
was a straight line, variability along a straight line, but absolutely
no trend whatsoever. We could see those spikes: a very rapid
rise, but then in half a year, they fall back again. But absolutely
no trend, and to have a sea-level rise, you need a trend.
Then, in 2003, the same data set, which in their [IPCC’s]
publications, in their website, was a straight line—suddenly it
changed, and showed a very strong line of uplift, 2.3 mm per
year, the same as from the tide gauge. And that didn’t look so
nice. It looked as though they had recorded something; but
they hadn’t recorded anything. It was the original one which
they had suddenly twisted up, because they entered a “correction
factor,” which they took from the tide gauge. So it was
not a measured thing, but a figure introduced from outside. I
accused them of this at the Academy of Sciences in Moscow—
I said you have introduced factors from outside; it’s not
a measurement. It looks like it is measured from the satellite,
but you don’t say what really happened. And they answered,
that we had to do it, because otherwise we would not have gotten
any trend!” and then he continues
“That is terrible! As a matter of fact, it is a falsification
of the data set. Why? Because they know the answer. And
there you come to the point: They “know” the answer; the
rest of us, we are searching for the answer.”
So the sooner this “introduced trend” is replaced with reality the better.
Cracking post Anthony. John Daly was saying this 16 years ago. The error range was +/- 75mm at best. That’s twice the sea level rise since 1993. Signal lost in noise indeed. I don’t see how this new gizmo is going to recover those data though. Changes in orbits due to solar wind variation etc are not steady or regular in magnitude.
There is also the human factor:
“In 2003 the satellite altimetry record was mysteriously tilted upwards to imply a sudden sea level rise rate of 2.3mm per year. When I criticised this dishonest adjustment at a global warming conference in Moscow, a British member of the IPCC delegation admitted in public the reason for this new calibration: ‘We had to do so, otherwise there would be no trend.’”
-Nils -Axel Morner-
http://tallbloke.wordpress.com/2011/12/02/sea-level-scare-stories-simply-scandalous/
I hope JPL will be telling us a lot more about their methodology than the article reveals so far. Well done for flagging up this important measurement issue.
Unsettling.
“TRF errors readily manifest as spurious sea level rise accelerations”
I feel like Captain Louis Renault in Rick’s Café Américain; now where are my winnings?
To me it sounds like the folks from JPL are looking for something to do… and funding to do it with. What better way than to say that there are problems with a satellite used to determine the effects of global warming.
I wonder how many folks would be unemployed without something new to work on.
They are simply getting desperate. Finding the appropriate kind of errors may help to hide the decline perhaps. For there is a decline indeed in satellite measured rate of sea level rise. Raw data from the CU Sea Level Research Group clearly shows that. There are 678 data points in that data file, since Dec 16 1992. The first 339 points show a rate of 3.5 mm/year, while the second half is 2.25 mm/year. That’s a 55% decrase in rate, which is huge. Especially because sea level rise is projected to accelerate.
It is not only the missing heat they should look for now, but the missing water as well.
Thanks John Stover for your insight.
I for one have always been sceptical about satellite measurements sea level rise to within a few millimeters. Sorry, that’s just the way I am.
Sorry NASA. You have hoodwinked us Taxpayers before on AGW. Your past results have been Alarmists and unscientific. And you have failed to purge yourself of the likes of Hansen.
As such, GRASP looks to be another excuse for NASA to get a Grasp on OUR money, while Grasping at the straws of Global Warming.
Answer: Just say No to GRASP
Unfortunately the US VLBI network may be forced to shut down, possibly eliminating full global VLBI coverage for GRASP
http://physicsworld.com/cws/article/news/2012/aug/22/us-telescopes-faced-with-closure
George Monbiot
Fraser Nelson makes the biggest blunder of his career by putting Nils-Axel Mörner’s, a serial promoter of nonsense, in his magazine
http://www.guardian.co.uk/environment/georgemonbiot/2011/dec/02/spectator-sea-level-claims
For me, it has always been hard to imagine that you can measure, from a platform orbiting at a constantly changing altitude, something as changeable as sea level, (waves, tides, gravity bulges), to an accuracy measured in millimetres. If they showed error bars for these calculations, would the possible errors exceed the headline figures? As “alcheson” says above, it is only the sea level relative to the coastline that matters in the real world.
Not really in my knowledge base but another way of looking at it might be in relation to GPS accuracy. GPS can accurately place to within around 0.1 or 0.2m, I believe(?) – and that is using half a dozen or more ‘geostationary’ satellites to get the best precision via cross-referencing (I think also with cross referencing to fixed land bases??) So, if they can only do that with GPS, how the heck can they better with ‘single’ satellite measurements of a moving surface?.
“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.”
-Maybe it can’t be resolved.
“Sorry, that’s just the way I am.”
-It is knowledge. If anyone has some knowledge of technology it is easy that know that all this claims of accuracy are bogus. A typical laser rangefinder has error of mm and we talking about 10km distance with both objects stationary.
Unfortunately they betray their bias and expected outcome in this presentation, they are assuming as a given that both are accelerating.
If they were unbiased, the wording would be something like “Determine if sea level is changing” and “Determine if Ice mass is changing, and the direction of those trends.”
Unfortunately this looks like a problem of confirmation bias in action they are trying to verify and increase the precision of the presumed trend and accelerations. No statement of any uncertainty of those basic assumptions.
Larry
Berényi Péter says:
It is not only the missing heat they should look for now, but the missing water as well.
Lolz, good one.
I think most of it ended up in the water table in Yorkshire, judging by the amount of rain we got this ‘summer’.
This is really poor show NASA, one minute temperature satellites aren’t recording data suiting your agenda, so claim there not good enough and use only land station data in the awful GISS, which invents data interpolated from hundreds of miles away. Now the sea levels aren’t supporting data with regards to your agenda, now want to build a satellite that apparently the same technology is not good enough for the GISS. Does hypocrite have to be included in your CV working at NASA or are people within having a disagreement?
Although this satellite is probably what we have been waiting for regarding trying to record more accurate sea level changes. Lets face it there has been two human changes in the data over recent years for no scientific reason, other to support further rises. One already quoted and the other, GIA correction is only applied to the global MSL time series, and has been estimated as approximately -0.3 mm/year [Peltier, 2006]
Spock: “It’s knowledge Jim, but not as we know it.”
Just Say NO!
To muslim outreach de-fund NASA NOW!
This is a good first step in getting our “science” on a scientific basis instead of the ego driven hubris of modelers. I would think that we should be getting more real bang for our investment buck too.
Well we’ll wait and see if the instrument needs adjusting. In any case, the error in the current sea level rise (ice thickness etc.) must be noticeable and in the direction stated or there would be no need for this new equipment. I’m impressed that when the edifice begins to collapse it takes so much with it – one thing after the other. I guess thats what happens when the whole CAGW thing has been built in secret by a group of one mind with limitless support and funds and the power to gatekeep the science. There is not much holding it all together.
If GRASP is a step to more accurate measurements, I am all for it. What we have now gives the warmists an excuse to make claims that are within the very large (relatively speaking) error range of the current instruments. Decreasing the error range will work in favor of climate realists.
As for the money…it employees educated and talented technicians and engineers, who have made good life choices to be contributing members to society. The amount we spend on this satellite would be a tiny fraction of the amount we spend enabling drug addicts to avoid getting real help for their problems (just one example). We live in a society that rewards those making bad life choices and punishes those making good life choices. Talk about being unsustainable!
American Council on Surveying and Mapping offers additional practical information on measuring sea level. A reprint of their December 2008 article is posted here:
http://tidesandcurrents.noaa.gov/publications/Understanding_Sea_Level_Change.pdf
Note that surveying practice is to measure sea level over a “tidal epoch”, which is defined as the 18.6 year lunar cycle (Metonic cycle in some references). See Figure 2 in the article. Quoting from the ACSM article (emphasis added in upper case for last sentence):
“Although current research on global sea level rise has been
focused on determining the water volume added from the melting
of glaciers and the extent of the thermal expansion of the oceans
due to global warming there is another aspect of climate and
sea-level change that needs to be considered. IT IS THE INTERANNUAL-
TO-DECADAL SEA LEVEL SIGNAL WHICH CAN BE LARGER THAN THE
ACTUAL GLOBAL SEA LEVEL TREND.”
Sorry but while Dr Doom hangs around NASA like tombstone ready to ‘adjust to death’ anything he does like like , this is not going to work.
I second what John Stover & Kev-in-UK say. The GPS systems using Continuously Operating Reference Stations (CORS) are the most cost effective and accurate way of measuring sea level. Data is collected continuously 24/7/365 from multiple satellites, which allows crustal motions to be corrected for, and therefore eliminated. The result is absolute sea level motion with sub millimeter accuracy. GPS is an under-utillized and under-rated source of valuable sea level and plate tectonic motion data.
Whatever follows on from this, I trust we’ll have some sound wayback data recorded,
Given the extraordinary statement to Mörner in 2003: ” … we had to do it, because otherwise we would not have gotten any trend!”, I anticipate further scope for adjusters and tinkerers.
I go with Kev-in-Uk’s comments on GPS. My $80 in-car GPS gets speed limit changes to within a couple of metres at 100km/hr, so I would expect fixed GPS altimetry to be more accurate than anything else.
With regard to tide gauges, I keep an eye on three locally, out of about 40+ in NQ Australia, and have only noted small cyclical changes.
Ok – there are differences between tide gauges:
Equipment: (radar, laser ranging);
Purpose: (keel clearance, storm surge calculations, sea-level change)
Also: Land changes (subsidence, uplift); Coastal topography – characteristics and changes.
All differ, none are necessarily “wrong”.
MSQ (Maritime Safety Queensland) lists 44 operational permanent tide gauges in Queensland:
Port Authorities – 11; MSQ – 2; AMSA (Australian Maritime Safety Authority) – 5; DERM (State agency) – 24; NTC (BoM – Federal agency) – 2.
Some of these are co-located, so there is some scope for detecting tinkering, use of model output instead of observations.
Mörner’s paper: “The great sea-level humbug” (covered above)
JCU paper 2008: “Mid-late Holocene sea-level variability in eastern Australia”
http://eprints.jcu.edu.au/1855/
I don’t know how much credence the NOAA has, but take a look at this link: http://tidesandcurrents.noaa.gov/sltrends/sltrends.shtml
Notice all of the little green arrows pointing up and indicating a positive rise in sea level. Well, if you look at the box below you will see that ‘green’ is for 0 to 3 mm per year. Zero. So one doesn’t know if there is really some indication of a rise. They could all be zero, for all we know.
The point being, the presentation of the data and analysis can be heavily biased in spite of showing null results.
Either that, or this is a canny way to get funding in the current environment.
The graph merges tide guage and satellite, as if the tide guage data stopped being recorded in 1990.
What is the tide guage record from 1990 to 2012?
Nasa has proven itself unworthy of funding. As long as they employ charlatans like James Hansen, they can not be trusted to objectively look at data.
The importance of finding “evidence” of sea-level rise (a preconceived expectation, based on their statement) is far outweighed by the 16+ trillion dollars in deficit that we are carrying around.
Not only “no,” but hell no.
What these NASA guys need is an excuse to tap into a budget line to ensure their pay checks into the future. It will also give them 17 years breathing space before any new trend becomes “significant.” I’m surprised they didnt ask for money to build a satellite that could travel back in time and measure sea levels retrospectively. Now that would have required a budget line that would have kept them in cream forever!
Rob UK – The Monbiot post you link to seems to be a guest post by Mark Lynas, who is among other things was “climate adviser to the [former, now deposed] President of the Maldives”. It would be interesting to look into Mark’s possible role in the staged propaganda piece of the underwater Maldives cabinet meeting (see http://news.bbc.co.uk/2/hi/8311838.stm ).
Whatever happened to Cryosat? Wasn’t that supposed to settle the questions on Arctic ice extent and volume?
What’s the next mission, STRAW? GRACE GRASP STRAW….sounds about right.
Are there any alarmists out there prepared to comment?
Grasp promises 10x better
TRUTHS promisses 10x better
Nigel Fox of NPL with the TRUTHS project is promising a similar 10 fold improvement in satellite measurements by providing on board calibration.
‘NPL in Space’ – new calibration satellite required to make accurate climate change prediction
That similarly emphasizes shows how large the uncertainties (“errors”) are with current satellite measurements. See Fox’s lecture and paper.
Context:
“Well, yes, we did promise that the old satellite would settle the question of sea level trend, but now that we need more money, er, no, the old data are no good and we really, really need a new sooper-improved satellite. And we totally promise that THIS one will do the job–until we need more money.”
After all, the first clean years from Envisat showed how the others were biased…
There is a need for a Bishop Hill-style review of the sea level adjustments to the TOPEX/Posiden record. It’s important to recognize that it’s an extremely complicated job to try to figure out actual sea level rise on short time frames. There are enormous issues of measurement error, splicing of records, adjustments and corrections that would leave any reasonable person with some doubt about the ability of the current process to determine sea level changes to 0.1 mm. (For example see the special issue on sensors at http://www.mdpi.com/1424-8220/6/6 ).
Steve Nerem is a smart guy and I think may be descibed as the “godfather” of altemetry measurement of sea level (he’s been working on it for at least 30 years). In the relatively early days of T/P (1997) he published a correction in Science on an earlier paper that had “shown” the sea level increase to be 3.9 mm/year (Science, 1995, Nerem, 5 May, p. 708-710). In the 1997 “correction” he states “The corrected value of global mean sea level rise observed since the launch of TOPEX/POSEIDON in 1992 is close to 0 millimeters per year, although there is evidence of additional instrument drift (5), suggesting a preferred value of roughly +2 millimeters per year. The corrected TOPEX/POSEIDON observations for 1993–1996 are in statistical agreement with the historical tide gauge record, which shows mean sea level rising at a rate of approximately 1.8 millimeters per year over the last 50 years (6)”.
GPS is accurate to within a few inches, even with multiple satillites.
To get an accurate record of sea level rise, it will take years of multiple satillites to establish a base verses actual ground based measurements.
I see Mark Lynas denies he arranged the Maldives underwater cabinet meeeting, and also shows some appreciation of the risk of hype in relation to sea level rise (see http://www.marklynas.org/2012/04/where-sea-level-rise-isnt-what-it-seems/ ). It’s nice to see him pay attention to the real science. His swipe at Dr. Morner is uncalled for (as Dr. Morner knows more about sea level than Lynas ever will – he been publishing in the peer reviewed literature for over 40 years, including critical papers on isostasy and eustasy).
I always scratched my head wondering how these satellites (temp, sea level, ice extent) could achieve the claimed level of precision. Turns out they can’t.
Once again its worse than I thought.This iOS modern science?So what is left to the climate crybabies?The unprecedented temperature rise is now dead, demonstrated false ,a creation of bias, by one of the original Team, welcome back Briffa. The rise of the sea’s phoney or unmeasurable.Emissions by man of CO2 are still rising, temperatures are not.Refresh my memory here, we were advised to panic because??.
This is modern science?
Actually, technically they’re correct. “Accelerating” means “changing” in physics; the direction is not specified. Could be speeding up or slowing down. In common speech, “decelerating” is used for the latter, but not in scientific parlance.
1. Knee-jerk response – why would I support funding anything at NASA? Create a new agency to oversee collection of data only. Let some other agencies and academics analyze it.
2. What will be the margin of error of the new instrument? Is it worth doing – in other words, will the new data be so accurate as to be useful in the measurement ranges we think are needed? How confident are we of those answers and who will stake their careers on those answers – let’s have some real penalties for those leading the effort if their claims turn out to be false.
Kev-in-Uk says:
October 30, 2012 at 1:38 pm
I can understand that radio telemetry/altimetry is inaccurate for transmittal reasons. What I cannot understand is how they can then ‘work’ back to a supposed accuracy of 1/10s of mm per year on a moving irregular surface! Sorry, but it just doesn’t compute……..
==========
They are averaging a LOT of observations. As I recall about a million a day give or take. Assuming that all the errors are random, that presumably cuts their measurement error by a factor of 1000. I suspect that if you are a lot better at math than I am, you might have some questions about whether the averaging procedure really produces exactly that much improvement when applied to a time series of measurements of a moving target. But intuitively, it seems like it ought to help a lot.
So let me get this straight:
They have satellites passing over land and sea without any regular initialization and measurement against – on each pass or ten – a solid reference point? What could be more simple and obvious? The satellite orbit cannot be known without that, not to the necessary precision of what is being measured. The orbit may be (and likely IS) an elliptical orbit in the first place, even if only a few millimeters. And when it passes over high gravity masses that orbit has to be continually affected. It seems to be admitted here that there is no continual re-zeroing.
But Reg, they CAN achieve the proper level of precision – but only by being as thorough as possible. And then maintaining that thoroughness. It is amazing in the extreme that they let this go this long before recognizing the failure at such a fundamental level. The entire reference framework could be drifting all over the place. If this was in engineering, heads would roll.
Steve Garcia
If the problem is “spurious” errors in current satellite based sea level and ice altimetry, why is the tide gauge data (in the simulated graph included in the Key Science Goals) adjusted to show a faster sea level rise?
Berenyi, maybe the lost heat has been used up evaporating the lost water?
I noticed a couple of mistakes in the JPL image.
1: They have “Ice Loss”. This should be ice fluctuation or change.
2: Sea Level Rise. This should be Sea Level Change or Fluctuation.
These mistakes shows that this organization is biased.
Why bother getting the baseline correct when you’re throwing in totally bogus ‘corrections’ like the glacial isostatic adjustment (GIA). It’s just a way to get around the current rate decline and get it back up to what they’ve been reporting all these years.
GIA is 0.3mm/yr, which doesn’t sound like much, but that’s an additional 10% of the real rate. They purport to throw it in to account for volume changes, but you don’t measure volume in mm unless you have a straight-sided container, which we hardly have at the seashore. You end up with a neither-fish-nor-fowl-number that is useless for what we really measure sea level for, knowing when
Dr Hansen can go fishing from his office windowwe’ll need to raise our seawalls, or the Maldives are going under.0.3mm/yr ain’t much, but it adds up –
http://i50.tinypic.com/8zfndk.jpg
They’ve also applied an ‘inverse barometer.’ Given that the barometric pressure variation over 7/10ths of the earth’s surface should average out close to zero, that’s another avenue for mischief.
Jimmy Haigh says:
October 30, 2012 at 5:51 pm
“Are there any alarmists out there prepared to comment?”
No? Thought not…
I have had the impression that the altimeter data series was regularly recalibrated to adjust the fit to match a preconceived sea level rise trend. An alternative explanation is that satellite altimetry directly affects the time rate of rise of sea levels.
Hm, I wonder if I did this right (somebody please check).
If there is any noticeable sea level rise, it should come from thermal expansion. Here’s the basic data:
average depth of oceans: 3688,4 m
volume: 1.332.000.000 km3
surface: 361.132.000 km2
specific heat capacity of water: 4181,3 J/kg*°K (average in range 5-30 °C)
expansion coefficient: 0,02315% / °K (average in range 5-30 °C)
If my calculations are at least roughly correct, the sea level rise of 3,9 mm/year should correspond to heat input of 2,2893 W/m2 (which is close to the maximum of IPCC AR4 “assessment” of anthropogenic radiative forcing of 0,6 to 2,4 – 90% probability 1,6W/m2); the 2 mm/year rise should correspond to heat input of 1,174 W/m2 – is that a oblique climbdown from previously excessive estimates of climate sensitivity?
miso
Kev-in-Uk says: “To my mind – it would be like estimating the surface area of a the leaves on a large tree from a mile away, with a stiff wind blowing! (at thats just in the summer!)”
That’s a good analogy, but it’s more like trying to calculate the average postition of all the leaves on one side of the tree from 2000 miles away, with a force 9 gale blowing.
There are so many things that have to be corrected for, the outcome is determined not by the data but by which adjustments you chose to make.
At that point the desire to get published and secure funding quickly dominates all the other “forcings”.
I do not understand what you are trying to measure when folks talk about small sea level changes. The gauges give hight above/below land land. But the hight of the land is feet/metres “above mean sea level”. Is it referenced to the earths centre of mass? You can not just use satelite orbits as they are not uniform around the earth and are continously changing. Money inflation indexs and FT index have a basket of prices but the baskets change over time and you can not really compare dollars in 1912 to dollars in 2012 using indexes.
Mike says: “They’ve also applied an ‘inverse barometer.’ Given that the barometric pressure variation over 7/10ths of the earth’s surface should average out close to zero, that’s another avenue for mischief.”
Colerado can no longer be given any credibility. As well as the GAIA [sic] adjustment the data is no longer available without the barometer adjustment. This new lack of transparency conveniently prevents anyone seeing what effect it has globally, which indeed should be neglibible. Clearly it isn’t otherwise they would not include it in the global mean sea level data they put up front for public consumption.
What they are still calling mean sea level is not such thing, it hovers phantom like, several mm above the waves. It is some kind of “sea level global warming index”. Continuing to present this as mean sea level data is dishonest and intentionally misleading.
Since public concern about rising sea levels is related to the risk of flooding, it has nothing to do with the rigged data they are calling sea level.
Mišo Alkalaj says:
October 31, 2012 at 12:32 am
I recall muddling a similar type of calculation some years ago, but the main problem is that sea temp changes occur in zones, not ‘throughout’ the volume – and some may be going down as well as up.
I am sure I have mentioned in a previous post that sea volume change is affected by multiple things too – such as crustal movements (laterally, as well as up and down) and subsea volcanism, atmospheric water content, subterranean (land) water content, sea and land ice changes, etc, etc.
People tend to forget about the full hydrological cycle when thinking about sea level. I am sure most here have had some school tuition about the water cycle? You know,- ocean water evaporates – makes clouds, then rains on the land, then slowly flows back to the sea, etc, etc. Any ‘measurement’ of sea level change (whether accurate or not) is simply a measurement of one part of the system, not the change in ALL the other parts of the water cycle – and those parts of the cycle introduce time lag effects, etc. So, in truth, what the feck are they actually measuring in terms of sea level?
DR says:
What’s the next mission, STRAW? GRACE GRASP STRAW….sounds about right
————–
I guess the STRAW mission should be Manned…..
feet2thefire says:
October 30, 2012 at 8:42 pm
So let me get this straight:
They have satellites passing over land and sea without any regular initialization and measurement against – on each pass or ten – a solid reference point?
==================
Not really. They actually do have a pretty solid Earth based (“Geocentric”) reference system. Depending on the satellite, they use GPS and/or DORIS (a sort of “backwards” GPS with fixed ground stations broadcasting reference signals) to continuously measure satellite position. The most recent satellites with Radar Altimeters claim average position uncertainties of a few cm. Beyond that, they average many measurements a second made continuously whenever they are not over land or ice to achieve what they hope to be sub mm accuracy.
Mike McMillan says:
October 30, 2012 at 9:42 pm
Why bother getting the baseline correct when you’re throwing in totally bogus ‘corrections’ like the glacial isostatic adjustment (GIA). … They purport to throw it in to account for volume changes, …
They’ve also applied an ‘inverse barometer.’ Given that the barometric pressure variation over 7/10ths of the earth’s surface should average out close to zero, that’s another avenue for mischief.
====================
I believe that there are two components to the CU GIA adjustments. One is the standard adjustment for ongoing changes in land reference elevation and the second — much smaller — is a recent addition to the handling that purports to “correct” for ongoing sinking of the ocean floor caused by the weight of water melted since the peak of the last glaciation. The first part is essential for tidal gauge measurements, but strikes me as being kind of weird for satellite measurements. The second seems to me to be even weirder since I think it will cause satellite and tidal gauge values to diverge over time unless the same “correction” is applied to the tidal gauge data.
BUT — the computations of sea level rise subtract “old” sea levels from “new” and the GIA components — whether appropriate or not — should cancel out (A+X) – (B+X) = A-B.
Inverse barometer is possibly a bit better justified. The problem is that about a third of the earth’s surface is land or ice and that average pressures over those areas may be different than average pressures over unfrozen sea surfaces. And not always by the same amount. It seems likely that without the inverse barometer correction, we’d see a seasonal affect in satellite measured sea level as the largely land Northern Hemisphere heated and cooled at a different rate than the largely water Southern Hemisphere.
Can they “adjust” the satellite data in accordance with the correct reference points, or is the entire dataset no more than junk?
Oso Politico wrote:
It is true, the green arrows are vague
But just hover the mouse on each one
If sea rise here is really a plague
This chart seems to deflate all the fun
For the stations with century scale
There’s no hockey stick giving a scare
Just a gradual trend … and they fail
To show any “accelerate” there
Looks like 2mm here is the rule
As it’s been since a hundred years back
This site serves as a useful new tool
(Look at Kodiak’s big earthquake whack!)
===|==============/ Keith DeHavelle
Can anyone tell me how they can have a ‘Terrestrial Reference Frame’ accuracy of ~1mm considering the Earths Crust is in constant movement?.
Mišo Alkalaj (Oct 31 at 12:32 am) says: “If my calculations are at least roughly correct, the sea level rise of 3,9 mm/year should correspond to heat input of 2,2893 W/m2 … expansion coefficient: 0,02315% / °K (average in range 5-30 °C)”
The thermal expansivity of sea water at average temp (~277K) and average pressure (~40MPa) is about 0.0187% / K.
A case of ”send more money”.
Greater accuracy would be good but would the alarmists believe a sea level drop?
Not that there is any meaning to this but it is strange looking at this slide:
http://wattsupwiththat.files.wordpress.com/2012/10/grasp_mission.jpg?w=640&h=492
one satellite measures “Sea Level Rise” (They don’t measure sea level lowering?)
one satellite measures “Ice Loss” (they don’t measure ice gain?)
one satellite measures “Gravity Changes”
Just strange wording
I’m curious as to just how they are going to make the system accurate to within 1 mm. I’ve been frankly enormously doubtful of this sort of precision from the beginning — humans would have a hard time achieving this precision with a really long measuring stick. Sure, interferometry has the capability of being very precise, but the atmosphere is hardly a linear propagation medium, paths are very long, the natural variability of the surfaces being measured with time is large (think ocean waves and tides and storms, think land surface tides, thermal expansion of the surface, and the fact that the surface is covered with vegetation and heat waves of the sort that create mirages and can provide false signals).
If I understand it, TFA above points out that in order to measure the true relative (to an arbitrary point deemed “the center of the Earth” as it moves through space in time) location of the surface, one has to begin by knowing the true relative location of the measuring satellite. The only way to set such a location in a satellite that itself has a constantly varying orbit as inhomogeneous drag forces act on it, many body forces act on it, and those forces themselves effectively vary in space and time (as the Earth isn’t a perfect sphere, tidal pseudoforces are constantly altering with the relative positions of sun, moon, and even planets (given a long integration baseline, even very weak perturbations can add up to millimeter sized changes in expected position) is to use positions on the Earth as reference points that triangulate the location of the satellite.
Sadly, there are no stable, stationary reference points on the surface of the Earth, and even if there were that does not completely eliminate the problem associated with uncertainties in wave propagation itself across a distance of many powers of ten of kilometers, so that 1 millimeter errors — still comparable to the “signal” one wishes to resolve, and accuracy on the order of one part in a billion — could be obtained.
To give you an idea of magnitude of the problem, let’s assume that a point on the ocean’s surface has a natural variability of one meter. The precise number won’t much matter, it is order of a meter (more some places, less others) as waves and tide operate. Statistically, in order to obtain a measurement of the mean, accurate to one millimeter, one requires many, many random samples drawn from the ensemble of possible snapshots at the point. Furthermore, one has to hold fairly precisely at the sampled point laterally as the satellite passes not directly overhead, but at an ever changing angle, through an atmosphere with ever varying moisture content, thermal profile, and hence index of refraction — even small aiming or obliquity errors cause one to sample the sides of waves over a different latitude and longitude than you think. This lateral pointwise precision needs to be reproducible — you have to hit and sample the same point, orbit after orbit, day after day.
Tidal gauges are perfectly designed for this because they can sample sea surface level at a single fixed geographical location thousands of times a day, day after day, year after year, with no holes. Even so there is clearly a lot of noise on their measured results because the systematic variation of the ocean via tides involves propagating and interfering large scale waves that are constantly being affected by things like weather events air pressure, storms, water temperature and that exhibit chaotic nonlinear properties. One cannot blithely “remove the seasonal and other periodic signals” from the data, because that presumes that you know what they are supposed to be, which begs the question of just what you are measuring. Or rather, one can remove them, but one is left with rather large and irreducible uncertainties — a single tropical storm like Sandy creates an air pressure linked storm surge that affects sea levels everywhere within a thousand miles or so over a period of weeks and creates persistent perturbations in the global sloshing of tidal waves around between the continents with a lifetime order of months. There are order of tens of tropical storms in the major oceans, and uncounted minor ones. All of this has to be averaged out to obtain 1 millimeter accuracy, and I personally don’t think even tidal gauge data can accomplish this, not even with many gauges, on a time frame less than decades.
Satellites are going to be strictly worse than gauges in nearly every respect but one. They cannot possibly sample single points as consistently. They suffer from the same problem of being unable to differentiate e.g. land subsidence, alterations of ocean volume due to a changing ocean floor and the locations of the continents (which frankly I don’t think anybody knows how to even estimate, since it would require measurements we don’t know how to make at points on the ocean floor and land surface all over the world) and so on from “true” SLR due to presumed GW. They suffer from a far worse problem in that if they were tidal gauges, they’d be tidal gauges mounted on a rod attached to a slowly sinking chaotic oscillator that swung them around all day, turned them off every few minutes for hours at a time, sampled only a handful of times when they were on, and got occasionally kicked by a drunken and irascible station keeper as he stumbled on by in the night. Finally, the samples they draw are not iid, nor are they systematic. They are too frequent to avoid autocorrelation, to sparse to be directly integrable as a continuous stream of samples damn the autocorrelation.
Consequently it is a bitch to do proper statistical analysis and return a fair estimate of the error, because you can’t use the number of samples to compute a standard deviation in the traditional way (too much autocorrelation) but if you use only the samples sufficiently separated to be able to count as iid, you have so few samples that it takes “forever” to get 0.1% accuracy in the mean from data with a natural variation of 1 meter.
One expects to need order of a million independent samples to get this sort of accuracy, and the time interval between the samples needs to be random and at least tens of autocorrelation times apart (neglecting the truly long period signals like the tides themselves). Ocean waves have a period on the order of tens of seconds, so one can sample at most once every few minutes. There are 1440 minutes in a day. One could get at most 1000 independent samples a day, which means that it takes three years to get 1 mm accuracy at any given point.
The satellite does do better in one respect that helps with this. It can perform its far, far worse sampling over many spatially separated points at the same time. It has to deal with spatial frequencies as it does so — again, if I were designing this I’d very much use random numbers to generate a monte carlo sampling with some sort of minimum distance of several correlation lengths — and it has to deal with the fact that the sampled area then becomes a curved surface, not a simple radial point — but one can imagine using this sort of thing to both get a better “global average” and to at least think that one is getting much smaller overall errors. This is clearly visible in the graphs — the satellite SLR data has very little noise — too little noise, with systematic variations too perfectly removed IMO.
In the end, though, it would be very disturbing if the satellite curves and the tidal gauge curves diverge, as they are apparently doing (although the presented graphs don’t show the extension of the tidal gauge data presumably to “hide the divergence”). Tidal gauges have their flaws, but they also are fully expected, collectively, to reflect true SLR as well as anything else, and their sources of error, as noted above, are straightforward and a simple average over the sites will almost certainly yield a highly accurate picture of SLR globally. The ocean can hardly rise “only in the middle” and not on all of the contributing coasts and gauge sites.
rgb
It’s now a race to spend money with alarmism in order to head off massive overspending by alarmism that threatens the viability of the country.
>>
Unfortunately they betray their bias and expected outcome in this presentation, they are assuming as a given that both are accelerating.
If they were unbiased, the wording would be something like “Determine if sea level is changing” and “Determine if Ice mass is changing, and the direction of those trends.”
>>
Hey man, they’re asking for big bucks, they’re not going say something silly like that in the prospectus. The fact that they put a spot light on the problem seems to say more about their intent.
Don’t image Hansen is running the whole of NASA, now.
There is nothing that prevents them from finding a negative acceleration (which is undoubtedly the case since even the bogus rise is slowing now).
Re Mišo Alkalaj says: October 31, 2012 at 12:32 am
Kev-in-Uk says: October 31, 2012 at 1:32 am
Leo G says: October 31, 2012 at 5:44 am
Assumption of an average depth, volume, and area results in a cylindrical ocean with linear depth vs. volume relationship. In actuality, the depth vs. volume relationship is nonlinear and described by the “hypsographic curve” which can be obtained from online references. Surface area vs. volume is also nonlinear. To throw some more fat into the fire, the porosity of the above-sea level soil needs to be taken into consideration as the assumed rising water must first fill in the pore spaces before the assumed increasing water volume manifests itself as an actual rise in water surface elevation.
Re rgbatduke says: October 31, 2012 at 7:23 am
Tide gages include mechanical and hydraulic damping (e.g. a stilling well) to minimize the effect of waves and rapid water movement. For example, see:
http://www.stevenswater.com/water_level_sensors/index.aspx
All this sounds a great deal like the discussions that occurred when GPS was first going up. The difference then was between the physicists who supported a system that required very precise measurement of the orbital parameters and computation of orbits based on understood physical phenomenon versus the math-statistics camp that supported orbital error determination and reduction by use of Kalman filter techniques. Everything was proposed including laser retroreflectors on GPS satellites in an attempt to identify and correct multiple sources of orbital error determination. In the end, it all came down to the problem now being discussed – precise and accurate terrestrial reference frames. GPS was highly self consistent but all that was not very useful until it was tied to a terrestrial reference frame whose position was extremely well determined.
Measuring absolute sea level from the center of the geoid is nice to know with respect to temperature versus volume calculations. But absolute sea level measurement with a highly consistent satellite system is not as useful as sea level determined relative to a terrestrial reference frame since what is really desired in terms of sea level information is the relative comparison of sea level to a terrestrial reference frame. More or less, we need the satellite equivalent of tide gauges and that depends on multiple accurate and precise measurements relative to a terrestrial reference frame.
Anthony, you say,
In point of fact, the displacement along the San Andreas fault is between 30 and 40 mm per year. In addition, the entire North American Plate is in motion at roughly 1.15 cm!! per year. There are also vertical shifts associated with both the Sierra and Coast Ranges that regularly affect altitude estimates based on the Mt Diablo datum and all the other data (datums to those who find that clearer) that are employed in the State Plane system. So, in fact correction is needed regularly. There is no such thing as a fixed point on the planet’s surface, either horizontally or vertically.
In case my previous post is a little unclear, every “motion” measured on this planet is a relative motion. Regardless of whether a geologist claims sea level changes are isostatic or eustatic, ANY measurement will contain components of both forms, plus errors introduced due to essential uncertainties about the precise position and elevation any datum used for mapping. .
Read the darn presentation, the errors that can e mitigated by the proposed system are of the order of 0.45mm/year. This is almost an order of magnitude less than the sea-level signal.
It amazes me how many comments were made out of complete ignorance that these measurement obviously have DOD implications. Let’s pretend for a change we live in the real world and not some fantasy fueled by the fossil fuel industries. In the real world our Navy has the largest Naval Base in the world next to ground that is subsiding next to an ocean having twice the amount of sea level rise as a global average. Sea level rise or fall doesn’t affect a ship at sea, but ships aren’t built at sea and they don’t spend their whole lives there. Having accurate data on future sea level changes is essential for the Navy’s future planning.
I’ve heard one person say we have NOAA, so why do we need the NSIDC, talking about sea ice. NOAA uses the NCDC to collect weather information all over the world and archives it. NOAA is a branch of the Department of Commerce, so someone figured it was a good idea to gather weather information to help commerce. The NSIDC gets it’s arctic sea ice information from the NIC, which is the Navy. The NIC is interested in daily navigation, so it is biased towards sea ice being present. The NSIDC is interested in archiving the information and will examine the data in more detail. There are obvious national security issues involved in arctic sea ice and that’s why there are satellites measuring it.
Let’s keep it simple and show me any of those NASA satellite programs that were done for alarmists, like some of you have claimed! I haven’t seen any climate program that didn’t have it’s origin for commerce or national defense reasons. Is it really such a big deal if some university gets to analyze the data for climate purposes or GISS, which is part of NASA, gets to analyze temperature data from the NCDC? Denmark manages to make arctic sea ice maps, so why shouldn’t we? These agencies are looking at data that exists with computers, so it isn’t like it involves a hugh expense.
As far as a three year lifespan for a satellite goes, that’s a normal prediction. IceSat2, which is to be launched in 2016, has such a three year lifespan and seven years of fuel. NASA tends to low ball the number, but a satellite can be taken out once it is functioning in orbit. The arctic sea ice might not even be there when it’s launched, but there are other reasons, such as ice sheets, topography and vegetation data.
From my take this JPL proposed satellite is looking for acceleration in sea level rise, which doesn’t mean increasing, but increasing at a faster rate. With 97% of Greenland melting and NYC flooded in 2012, you might want to spend some money to avoid spending much more in future expenses, if proper planning isn’t done. Remember, it isn’t just the victims of a disaster that foot the bill.
Gary Lance says:
October 31, 2012 at 12:55 pm
Wirth respect, I’m not sure I am following your logic re the Naval base/ships issue. I am assuming you are referring to dry docking of ships? and in that instance, I would agree, that if we had say a few feet of sea level rise, this could present a problem to dry docks that could be overtopped by rising seas. However, as both a yachtsman and an engineer, I fail to see how this point could remotely warrant the slight ‘alarmist’ tone in your post. (apologies if I misread that tone!).
Firstly, a general SLR of 2mm per year would equate to 300mm or about 1 foot, in 150 years. Now, I am pretty sure that all the current ships in use will have been replaced by then, probably built in bigger and newer yards!
Secondly, dry docks and harbours can be ‘raised’ relative to the adjacent sea level quite easily, I would have thought. And again, on a timescale of adding 1 foot of ground around a dry dock, and 1 foot of extra height on the dock gates every 1o0 or so years – this is hardly a majorly technical task (IMHO)
To put the same SLR in terms of the recent storm surges seen via Sandy – do you not think that the overtopping protection likely to have been ‘designed’ into dry docks from tidal and storm surges would not already more than cover the anticipated 1 foot of SLR in 100 years (or whatever)?
Just trying to inject some perspective to your naval issue…….
regards
Kev-in-Uk says:
October 31, 2012 at 1:50 pm
The information about Norfolk comes from the Navy. Perhaps you should stop the video and review the charts of the reinsurer near the end. I have found these insurance charts in google images. The charts don’t involve payouts based on claims, but are talking about increases in incidents. The insurance charts are clear evidence of more extreme weather related events.
The IPCC report claimed the arctic would be ice free around 2100. Few think it will not be ice free by 2020 and some believe it will be ice free by 2015. We don’t have experience with large ice sheets melting and there is data to support them melting faster than previously thought.
If the ships aren’t going to be around when sea level becomes a problem, then they will be replaced by ships built in Norfolk. It’s a good idea to know just how fast the past sea level rise is and what can be expected in the future. Our present trend of negative Northern Hemisphere snow cover anomalies in June is going to make those every 150 year Greenland melts a new reality. People are going to quickly catch on and realize those sea level rises by the IPCC are conservative estimates. So far, ice sheets have contributed very little to sea level rise. To put the snow cover anomaly in perspective, Greenland has an ice sheet of 1.7 square kilometers and 2012 had an anomaly of 5.8 square kilometers with nothing in the trend to suggest things will get better.
http://vortex.accuweather.com/adc2004/pub/includes/columns/climatechange/2012/590x558_07091839_figure5a.png
My point was a simple one and I asked for an example of a climate program that didn’t originate out of concerns for commerce and defense.
Sea level rise has not been accelerating. It is currently on its long term trend line. However, the more recent decadal trend has been declining. This is in line with ocean heat content (OHC). And the long term rise since the LIA has been constant, despite a large rise in CO2. This is also supported by ARGO data, which falsifies the models. Even NOAA shows that SL anomalies are very minor.
There is no empirical evidence to support the belief in catastrophic AGW, or in AGW for that matter. If the globe was warming any more than its natural global warming trend since the LIA, the warming would show up in the OHC and the sea level. But it doesn’t.
Readers may disregard all of Gary Lance’s wild-eyed arm waving. He is simply wrong. There is nothing unusual or unprecedented occurring.
D Böehm says:
October 31, 2012 at 6:59 pm
It’s amazing NASA relies on satellite data, when they could just use your mouth. Wishful thinking isn’t data to support your position. Hint: Either the ice stops melting because it stopped warming or it ran out of ice. There is nothing to suggest it should stop warming and there are only suggestions that the warming should be a certain amount over a certain period of time.
You brought up AGW here and I just said ice sheets are melting and sea level rise is going to happen faster than expected. The only evidence needed is simple observation, but that requires finding video information that actually shows you the changes in Greenland.
It isn’t that hard to calculate the amount of radiative forcing produced by Milankovitch Cycles over a time period, but that amount of radiative forcing is enough to drive us in and out of ice ages.
The unusual or unprecedented has just started, but the concept of frequency is beyond your cognitive capacity. Get used to paying for it and keep telling yourself it’s all natural! The bill for exceptional weather isn’t going to ask what you believe or care one way or the other. All the voodoo science in the world won’t protect you from that!
Gary Lance opines:
“The unusual or unprecedented has just started…”
No, it has not. There is no empirical, testable evidence for your baseless assertion. The climate Null Hypothesis has never been falsified. Get educated, puppy.
Let’s presume, for the sake of discussion, that sea levels are rising (or for that matter lowering) sufficiently to have an effect on humans. Would it be more pragmatic to direct our energies and resources to adapting ourselves to a higher (or lower) sea-level or for us to attempt to adapt the planet in order to accommodate our preferences?
Re Gary Lance says: October 31, 2012 at 6:37 pm
Kev-in-Uk says: October 31, 2012 at 1:50 pm
The National Council Marine Board “Responding to Changes in Sea Level – Engineering Implications”
http://www.nap.edu/openbook.php?isbn=0309037816
provides guidance on responding to sea level rise predicted as of the 1987 publication date. Harbor structures are addressed. See Page 107 for dry docks, wet docks, and floating dry docks. The report summary provides an overview of main points of sea level rise discussed here. Hampton Roads in Figure 1.1 shows a relative sea level rise of 3.6 mm/year, or about 1.2 ft per century, based on data before 1987.
The 1987 predictions predate recent sea level measurements, so this report would also provide a useful comparison between what was predicted and what has occurred.
Tide gages include mechanical and hydraulic damping (e.g. a stilling well) to minimize the effect of waves and rapid water movement. For example, see:
http://www.stevenswater.com/water_level_sensors/index.aspx
Sure, but in the end this is just a mechanical way to average over or filter out short period fluctuations. One might just as well not have such things, record the levels on a granularity of (say) 0.1 seconds, and apply numerical filters. At least in the latter case one would have more control over precisely what your frequency cut-off looked like, and one could ensure that it was precisely the same gauge to gauge, where mechanical devices (especially ones that have some ability to be mechanically tuned) are almost certainly all going to be slightly different in the way they damp out the short time stuff.
This isn’t intended to be critical — I’m sure that the mechanical damping mechanisms do in fact serve their purpose, and that the tide gauges are in fact pretty accurate. They are also apples to apples across a very long time series of data, which is almost more important than their accuracy or how perfectly they dampen and filter the noise relative to the signal. They are still susceptible to a wide range of sources of non-predictable “noise” — ordinary variation in the atmospheric pressure uplift or press down the ocean by amounts comparable to the annual or even decadal signal on a timescale of hours to days. One “assumes” that these effects average out, and of course in a long enough time base, and with enough independent samples they will, but in the meantime one feature of “randomness” is how surprisingly much “order” is embedded in it, how easy it is to find the fluffy little sheep, bounding along in the clouds or the big dipper outlined in the stars.
That’s why personally I’d prefer to have the microscopic data, noise and all, for a long, detailed timeseries, with damping only of effects less than order of a second or so. Then form the full fourier spectrum of the result down to the upper bound frequency cut-off. Then identify the primary structure, fit its shape, and look for the asymptotic value of the zero-frequency component that is, in fact, the best estimate of the SL. And I’d probably do this in a long time window (effectively coarse graining intervals of the series) to TRY to get the secular slow time variation of the zero-frequency component, oxymoronic as that is.
Which is, no doubt, very similar to what is actually done with a lot of the timeseries data of this sort, and is as good as it gets given the data, as long as there are no confirmation-bias thumbs on the scales or sources of long period systematic error. Which, sadly, seem to exist in abundance in climate science. It isn’t the completely automated filters applied to timeseries that bother me, in other words, it is the corrections for things like UHI or systematic measurement error in the temperature series or the difficulty of determining an absolute/reliable frame of relative reference in the SLR satellite series.
rgb
George Pennington says:
October 31, 2012 at 8:46 pm
Let’s presume, for the sake of discussion, that sea levels are rising (or for that matter lowering) sufficiently to have an effect on humans. Would it be more pragmatic to direct our energies and resources to adapting ourselves to a higher (or lower) sea-level or for us to attempt to adapt the planet in order to accommodate our preferences?
The only thing I can think of when you say adapt the planet is mitigation, such as geoengineering. If you are thinking in terms of building a sea wall, it might be a good idea to know if doing so is practical. People don’t build along the shore to look at a sea wall and you can’t wall in a country. It might be more practical to visit the shore and not live there, if being flooded becomes a problem. The key is to adapt to the planet and don’t live where you can be flooded.
For the sake of discussion, we really have to ask ourselves what evidence points to sea level rise and I’m not even going to entertain the concept of sea level lowering? The evidence for the past 2,000 years shows a stable sea level and only recent rising. A sea level rise requires additional water or heating causing thermal expansion. The evidence on glaciers is they have lost mass and are losing mass at an alarming rate. The evidence on wetlands is they were reduced where mankind has lived and increased in areas where permafrost has melted. The evidence on aquifers is they have been lowered. When you look at the amount of water added to oceans, the glaciers are what’s significant. I don’t find tundra wetlands significant, because the water was already on land, but dams are the most significant thing man has done to reduce sea level rise and warming causing more water vapor in the atmosphere is the most significant thing the planet has done. The evidence for increases in ocean temperature are what they are.
The fact that we don’t have perfect data doesn’t mean there isn’t sufficient data to alarm nations about a changing world. If nations weren’t alarmed, they wouldn’t be going to all this trouble to build satellites and things like the ARGO array. For every person who suggests the rate of sea level rise will be a linear function, history and logic shows it never is that way. Sea level rise is a time function, like a Gombert function, that starts off slowly and accelerates. The early stages look linear, but they aren’t. Now, you can down play the data slope, claiming it’s 2 mm/yr, when the best data shows 3.11mm/yr, but until there is accurate data to determine the rate of acceleration, you aren’t going to be able to calculate the rate over a time period.
Galane says:
October 31, 2012 at 11:53 pm
In laymans terms, the current methods of measuring sea level change based solely on satellite observations are akin to trying to measure things using a ruler with the first inch made of sponge rubber.
What gave you the idea sea level change is based solely on satellite observation?
Here is 4% of the sea level rise measured by a man who spent the last 31 winters living on top of it (at the time of the video, of course). Try to pay particlular attention to known facts, like how fast this glacier is moving and what is causing it!
Gary Lance says:
October 31, 2012 at 8:18 pm
[some text edited out]
It isn’t that hard to calculate the amount of radiative forcing produced by Milankovitch Cycles over a time period, but that amount of radiative forcing is enough to drive us in and out of ice ages.
Radiative forcing (TSI) is part of the Milankovich forcing, but not all – since glacial inception always occurs during falling obliquity, and since recent research has identified a bipolar “seesaw” – reciprocal warming and cooling at the two poles – it appears that decining obliquity somehow destabilises the symmetry between the hemispheres in global oceanic circulation, causing the unstable excursion leading to the bipolar seesaw. So orbital kinetics play a role, not just TSI – in fact previous inceptions have not required particularly low TSI values – orbital phase resonant effects seem to be dominant. Interestingly the polar seesaw indicating the imminent end of our current interglacial has already begun.
Your comments on SLR are curious, since SLR is currently deccellerating toward a slow turnover. This will, in future decades – and I agree with you on this point – give us all interesting times, climatically speaking.
So once again a Gary Lance claimed “fact” is shown to be false. Lance asserted upthread that some glaciers move at the speed of a fast walk. That would be 4 – 5 mph. But in the video posted above, the world’s fastest moving glacier flows at the speed of only 113 feet per day. At even one mph, the glacier would flow 24 miles in one day. That would be more than 126,000 feet per day. And at 4 mph the glacier would move more than a half million feet per day.
That is typical of Gary Lance’s comments. He is a know-nothing who cuts and pastes his misinformation from unreliable alarmist blogs like SkS. Readers would be wise to question everything that Lance posts, because most of it is flat wrong, as his glacier nonsense shows.
Gary Lance pretends to be knowledgeable about a range of subjects, from AGW to Arctic ice to sea level expertise. He is none of those things. His posts are filled with misinformation, as several commentators have repeatedly pointed out.
phlogiston says:
November 1, 2012 at 7:08 am
There is no data or observation to suggest a decelerating SLR.
The hemispheres are simply different kinds of places.
D Böehm says:
November 1, 2012 at 9:52 am
Look, Troll! If you haven’t spent the time to learn anything that’s your problem and stay stupid. I’ve seen a man trying to talk to a camera and having to walk quickly to stay in front of an advancing glacier. It was on TV years ago. You aren’t worth the trouble to find things to prove you are wrong again.
You think you have the right to behave like a forum troll simply because someone believes adding greenhouse gases causes warming. If you can’t discuss the climate subject, then there is no sense in posting anything to me. I keep telling you I’m not the subject.
Gary Lance says:
“If you can’t discuss the climate subject, then there is no sense in posting anything to me. I keep telling you I’m not the subject.”
If you will notice I was addressing the readership in my last comment, not you. However, you are the subject for the simple reason that you continue to post misinformation.
You assert: “There is no data or observation to suggest a decelerating SLR.”
Wrong again. In fact, there is ample data and observations. I posted numerous links in my 6:59 pm comment yesterday showing that the decade over decade rise is moderating. That is observational based data. Therefore your false assertion is as wrong as your ridiculous claim that glaciers flow at the speed of a fast walk.
You can label me a troll all you want, but I will not stop holding your feet to the fire when you make false assertions, which you do constantly. Most of the regular commentators here have forgotten more than you’ve learned about the subject. You are a noob here who floods the threads with pseudo-scientific narratives. I advise you to search the WUWT archives on any subject you feel compelled to comment on, and learn the facts first. Because the nonsense you write is pretty much fact-free, as I and others have repeatedly pointed out.
Stunning…. just stunning…
These are the kinds of people (lance) that I encounter regularly, and I assume many of WUWT’s readership as well. Loaded with “facts”, most of which are not only demonstrably false or incorrect, but based on conjecture and projection, not observation and not reality.
For the record, there is only one troll on this thread.
D Böehm says:
November 1, 2012 at 11:08 am
Claiming data was posted isn’t posting data.
Did cooling cause a melt on 97% of the Greenland ice sheet this year or a record minimum arctic sea ice by 4 different ways to measure volume, area and extent? Did cooling cause a record Northern Hemisphere June Snow Cover anomaly?
Water has to go somewhere besides the ocean to decelerate SLR, so where did it go? Showing where it went requires more than the hot air of just saying it, it requires proof supported by all the data available.
Lance says:
“Showing where it [water] went requires more than the hot air of just saying it, it requires proof supported by all the data available.”
Wrong: Ei incumbit probatio, qui dicit, non qui negat; cum per rerum naturam factum negantis probatio nulla sit. – The proof lies upon him who affirms, not upon him who denies; since, by the nature of things, he who denies a fact cannot produce any proof. As to the conjecture that receding Arctic ice is undesirable: the onus lies on those who say so. As to the claim that there has been an alarming late 20th century spike in global temperatures: the onus lies on those who say so. But skeptics have shown that the alarming temperature spike is an artifact of zero baseline charts. It is not reality.
You see, skeptics have nothing to prove. It is the fact-challenged alarmist crowd that insists that every natural change is a bad thing. That is their basic belief. Therefore, they have the onus of proof, so they must demonstrate global damage or harm as a result of whatever it is they are currently arm-waving about. But so far, there is no scientific evidence showing that receding ice is a problem. There is no global harm, therefore receding ice is ipso facto ‘harmless’. In fact, it can be shown that it is a net benefit.
GPS is calibrated by measuring the gap to ground based stations and as far as I know it claims vertical calibration around 1 cm not mm. The satellite to earth centre gap is not measured. So if a non-GPS satellite uses the GSP framework to measure sea height, it is sea height compared to the GPS grounds stations, ,probably on the USA plate, not the centre of the earth.
Would appear to make more sense to just look at gauges stuck on rocks 150 years ago, unless you are in the space business like NASA. .
D Böehm says:
November 1, 2012 at 12:08 pm
You said SLR was decelerating, so I’m the skeptic. You made the claim, so back it up!
Where is the proof and where did the water from observed melt go? People in Iowa were helped out by the government to dig deeper wells, because the aquifer has been lowered. People in Spain have drained an aquifer so much they think it caused an earthquake. Glaciologists have calculated mass loss on glaciers and they study glaciers before dams are built to make sure the dam will have an adequate water supply. There is plenty of evidence of mass loss of water from the land to the oceans.
If you can’t back up what you say with all the data, it’s just mouth.
I’ve long thought that my beloved NASA should be done away with. Replaced with SEA – Space Exploration Agency. No more missions looking back at Earth. If it isn’t outside of our atmosphere, it’s none of their business.
Gary Lance says:
1. Scroll to the top of this page.
2. Hover over “Reference Pages” – hover over “Ocean” – select “Ocean Page”.
3. Scroll down until you see the curves that are labelled “Sea Level Rise” or some such.
4. Learn.
TomB says: “I’ve long thought that my beloved NASA should be done away with. Replaced with SEA – Space Exploration Agency.”
Ditto!
Your beloved NASA is gone, replaced by a political activist NASA.
Only part of NASA worth saving are those working with non-Earth probes, satellites, and explorers.
Big thumbs up to Mars explorer teams.
Gary Lance: “I haven’t seen any climate program that didn’t have it’s origin for commerce or national defense reasons.”
Nothing like jumping on the Climate Change bandwagon is there?
Can’t get funding for national defense program “Alpha?” Re-submit it as evaluating the impact of AGW on program “Alpha”.
CodeTech says:
November 1, 2012 at 6:23 pm
Gary Lance says:
You said SLR was decelerating, so I’m the skeptic. You made the claim, so back it up!
1. Scroll to the top of this page.
2. Hover over “Reference Pages” – hover over “Ocean” – select “Ocean Page”.
3. Scroll down until you see the curves that are labelled “Sea Level Rise” or some such.
4. Learn.
I’m not going to learn science by ignoring the simple fact that a La NIna will remove water from the oceans and it will return about a year later. SSTs also tend to be slightly less in an La Nina. Just how can someone claim a trend by cherry picking times when all scientists know the data isn’t normal at that time? The climate isn’t going to be dominated by a La Nina and if it was it would still follow the trend to warm from a new base.
What do you think the trend will be when a strong El Nino like 1998 returns?
Another science that is not settled.
Darren Potter says:
November 1, 2012 at 8:38 pm
Gary Lance: “I haven’t seen any climate program that didn’t have it’s origin for commerce or national defense reasons.”
Nothing like jumping on the Climate Change bandwagon is there?
Can’t get funding for national defense program “Alpha?” Re-submit it as evaluating the impact of AGW on program “Alpha”.
It’s obviously went over your head that the only thing involving climate is analyzing the data already gathered for national defense reasons. The programs were started for defense reasons.
The first real operations of our nuclear submarines in the arctic involved surfacing exercises. Do you have any idea why nuclear submarines were so interested in surfacing? Do you have any idea why the conditions of arctic sea ice became such an interest to the Navy and they didn’t want to use active sonar on nuclear submarines to determine those conditions?
There was no program sold for AGW reasons and saying so is just making things up. You live in a fantasy world.
The United States Navy, with all the naval bases throughout the world is very interested in accurate data on sea level rise. It would be interested if the sea level was declining, too.
TomB says:
November 1, 2012 at 6:02 pm
I’ve long thought that my beloved NASA should be done away with. Replaced with SEA – Space Exploration Agency. No more missions looking back at Earth. If it isn’t outside of our atmosphere, it’s none of their business.
Those satellites were put in orbit for obvious defense reasons, originally back in the Cold War, but your type wants to privatize the military, too. How has that worked out in Afghanistan, Iraq and Libya?
You act like it’s a shame that a branch of our government would take meteorological data already archived and analyze temperature data with computers that are idle. You act like it’s not in the interests of our government to know if it’s warming, because such knowledge doesn’t suit your agenda. I say if they have some computer time, analyze the data for relative humidity too.
Gary Lance says:
“…your type wants to privatize the military, too. How has that worked out in Afghanistan, Iraq and Libya?”
Wrong as always. The military is not privatized. Iraq, Afghanistan and Libya were fought with a national military. Can you not get even the most basic facts correct?? Your mindless narratives are comically inaccurate.
Gary Lance says:
November 1, 2012 at 10:27 am
phlogiston says:
November 1, 2012 at 7:08 am
There is no data or observation to suggest a decelerating SLR.
The hemispheres are simply different kinds of places.
Here is a recent WUWT analysis of recent SLR. It is not rising, in the southern hemisphere especially:
http://wattsupwiththat.com/2012/05/16/is-sea-level-rise-accelerating/
Why do you need to resort to special pleading to exclude the SH? And the same also for Antarctic sea ice, record high this year? Do CO2 radiative IR effects only operate in the NH?
Also, go to http://www.climate4you.com/ and the ocean page, and scroll down to the bottom graph.
This gives the derivative of SLR, the rate of rise. This is clearly declining since 2002.
Gary Lance says:
Got it.
Here’s one of Steve Nerem’s recent papers showing a significant drop in sea level explained by La Nina (see http://www.agu.org/pubs/crossref/2012/2012GL053055.shtml )
Also consider possible oscillations over the periods being measured (see http://www.agu.org/pubs/crossref/2012/2012GL053055.shtml ).
James Houston of the US Army Corps of Engineers has been doing some interesting work on GIA, subsidence, and GPS in relation to measuring sea level. Fortunately his recent paper is open access at http://www.jcronline.org/doi/abs/10.2112/JCOASTRES-D-11-00227.1 .
BEWARE – this is just another ruse in NASA’s continuing quest for world dominance. You have been warned before…
http://climatesanity.wordpress.com/2011/06/06/deception-from-nasa-satellites-are-true-cause-of-sea-level-rise/
Tom