# Sea level rate of rise shown to be partially a product of adjustments

People send me stuff. Here we have another case of value added adjustments that increase the slope, much like temperature.

This email forwarded from Steve Case reads as follows:

The University of Colorado’s Sea Level Research Group just published the 2013 Release #1 of their Global Mean Sea Level Time Series.

I discovered that these periodic releases are on the net all the  way back to 2011 Release #1. So I downloaded all nine of them.

2012 release #1 has 628 entries up to January of 2011 so I had Excel’s slope function calculate  the rate of sea level rise for that time series of 628 entries across all nine releases.

What I found is that the rate of sea level rise has been bumped up twice since then, once in 2011 and the the latest in the current release.  Here’s a link to a graph  to illustrate the point:

http://oi45.tinypic.com/2vmenpv.jpg

Coupled with the GIA increase of 0.3 mm/yr that was made prior to these nine releases the rate of sea level rise has been bumped up 0.43 mm/yr in the last few years.

This sort of thing has been going on more or less regularly and it seems to go only one. way.

Here are the links to the data:

## 114 thoughts on “Sea level rate of rise shown to be partially a product of adjustments”

1. Typical. Trying to engineer an acceleration to fit the models.
The isostatic adjustment was introduced last year as far as I remember?
(Adjusting for the sinking of the sea floor).

2. matt says:

So they need to fudge sea level data too eh?

3. Ronald says:

Why be surprised?
If there is no global warming you make it.
Is there no extreme ice melt you make it.
Is there no sea level rise you make it.
If glaciers wont meld you make them meld even if you have tho use a blowtorch.

Why is this a suprice? We all know AGW or CAGW is FRAUD the only thing to figure out is how far when they and when someone comes out and say stop this is to far.

All I now is that in normal science they already where out of job and possibly in to prison now.

4. jon says:

Well earlier this was the facts?

http://www.john-daly.com/ges/msl-rept.htm
“As Fig.20 shows, the current sea level rate of rise after cycle 276 is +0.9 mm/yr, half the rate claimed for the last 100 years, and less than one fifth the rate claimed for the 21st century”

But later:

http://www.john-daly.com/altimetry/topex.htm
+2.2 mm/yr

And now its up at :
3.2mm/yr?

Great!

5. John Peter says:

Reminds me of interview with Nils Axel Morner back in 2007. Not much has changed since then. It would be interesting if the author had inserted tide gauge measurements over the same period.
http://www.climatechangefacts.info/ClimateChangeDocuments/NilsAxelMornerinterview.pdf
“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!” So we have the adjustments to sea levels and the surface temperature records and I wonder what else. What about ocean heat content?

6. Coupled with the late 2011 ARGO adjustments and the bad splice with XBT data in 2003, the indications are the measurements (which for satellite altimetry have an error of at least +/- 75mm) are being calibrated to radiative greenhouse theory, not anything real on Earth’s surface.

7. Peter says:

However, i’m sure they reference their data against known surface heights (large salt pans) then use this to correct satellite drift (the adjustment). They must give a reason / data for their correction.

Of all the adjustments in climate, height must be the least murky / easily verified or explained, surely.

8. Robertv says:

Dr. Nils-Axel Mörner

9. Pethefin says:

I wouldn’t call these value added adjustments since that presupposes agreement on the value of the end-product, rather this is yet another example of values-based-adjustments in accordance with the post-modern-science-activism

10. Byron says:

(Sigh) Why am I not surprised ? As with most things CAGW related the only acceleration seems to be in the size of adjustments

11. The story of satellite sea level adjustments is even older. The values before 2011 can be assessed via WayBackMachine.

I made an analysis of the results of the adjustments of the ESA and Colorado Sea Level data over the years a couple of month ago (Google translation).

Conclusion, Even though the sea level rise rate has decreased over the years, the rate of sea level rise was kept more ore less constant at above 3 mm/year by applying various “adjustments”. This year it seems, the data is being made fit for the next IPCC assessment report…

12. Dodgy Geezer says:

13. batheswithwhales says:

Can anyone come up with ONE instance EVER, where adjustments have resulted in less warming, less sea level rise, etc?

If not, this tells a pretty clear story. It is totally unreasonable that all adjustments, year after year in multiple datasets and in multiple scientific disciplines should all contribute in the same direction – towards “confirming” a dramatic global warming.

14. Toby says:

So excluding GIA, there has been a change of 5% in the rate. The claim is that is fraudulent … surely that is hardly worth the trouble? How so we know that it is not due to a monthly re-calculation?

15. Lawrie Ayres says:

Climate scientists, advocates and politicians following the AGW line have been shown to exagerate, fudge data and tell lies. They have shown themselves as untrustworthy so I always get suspicious when they make apparently outlandish predictions. These are supposedly educated and intelligent ( sometimes mutually exclusive I realise) people who by now should know they are wrong, wrong wrong. However whilst continuing the false PR some are acting in a way which is at odds with their public utterances. E.g Al Gore is sure sea will rise by up to six metres but buys a waterfront property in SF; Tim Flannery predicts an eight story sea rise but buys a property on the Hawkesbury river just above high tide and accessible only by boat. Tim also sprouts the urgent need for geothermal and has shares in a company that just happened to receive \$90 million in Government grants. Unfortunately for Tim the share price has all but hit zero so he doubles his efforts to promote the evils of CO2. Local government has tried to move people from areas seven metres above current sea level stating that sea level rise will inundate these properties. Some people, believing the lies, sell at reduced prices to escape the coming catastrophe and I wonder who buys; folk like Flannery and Gore??

When someone who should know better keeps a discredited scam going and starst profiting from others who believe them I start to wonder. After all our own government is doing just that with the Carbon tax.

16. DirkH says:

Looks like scientific institutions have entirely fallen prey to activist rent-seekers.

17. How does one go about measuring sea level to a tenth of a millimeter?

18. Don K says:

That’s interesting. Despite the fact that Topex/Poseidon sea level measurement technology appears to be superior to ERS and tidal gauges, I have come to mistrust the numbers coming out of CU. This doesn’t help.

Tangentially, does anyone know why they seem to be applying a Glacial Isostatic Adjustment (GIA) to satellite measurements? GIA is necessary and appropriate although not necessarily adequate for tidal gauge measurements where it (partially) corrects for tidal gauges being (slowly) moving platforms. Satellites are moving platforms also, but the satellite motion has already been corrected during orbit determination, and should not, I should think, need additional correction.

Anyway, I no longer trust these guys. I think that they are likely practicing advocacy disguised as science. For a description of how of science is properly done, see Richard Feynman’s quite remarkable “Cargo Cult Science” speech http://www.lhup.edu/~DSIMANEK/cargocul.htm

19. Bjarne Bisballe says:

Dutch scientist found that the moon has some influence on the measured sea level based on cyclic variations of the orbit of the moon. Paper here:

The moon pulls the ocean water from the southern to the northern hemisphere in cycles of 18.6 years. The oceans then get more or less the form of pear with the stalk heading north and south alternately. That should have an influence on the sea level of at least at few millimetres and that effect should not be forgotten when you monitor sea levels. You have to monitor for whole cycles of 18.6 years to get correct data. For the time being, the stalk points south.

Besides that effect, the mentioned moon cyclus should, according to this paper:

http://ansatte.hials.no/hy/climate/theClimateArticle.pdf

also have a more general influence on the climate in the northern Atlantic region.

20. jim2 says:

I’ve tried to find the sea level rise on their site that have no adjustments – just the sea level that comes out of the calculations for the “raw” sea level. It seems so dishonest not to post that chart so we can see better the effects of the “adjustments.”

21. John says:

Would someone please write a book on solely the adjustments you could call it “The adjustment burro”
Dare I say the only real hockey stick.

22. MieScatter says:

osopolitico, sea level is typical measured with a laser altimeter. An example is on the Jason satellite, and the handbook is here:
ftp://podaac.jpl.nasa.gov/allData/ostm/preview/L2/GPS-OGDR/docs/userhandbook.pdf

The error budget shows that an individual measurement expects an uncertainty of the order of cm to ~11 cm.

If I’ve got it right, then that is one measurement. But your uncertainty in measuring an average value gets smaller as you take more measurements. It crosses the equator ~25 times per day. I can’t find the sampling frequency, but the resolution is ~4 km. 12.5 full orbits in a day at ~4 km resolution is up to 10,000 measurements per day (assuming all ocean). Let’s say 6,000 to represent unfrozen ocean. The average cycle length at which they report a value is just under 10 days, so about 60,000 measurements per value.

The error in the AVERAGE value if an individual measurement has a 10 cm error and you have 60,000 independent measurements would be (in metres) 0.1 / SQRT(60000) = 0.0004 m or 0.4 mm.

Given that the error is of the order of tenths of a millimetre then standard scientific practice is to report the value to tenths of a mm. As it’s an average of many values then it is also common to extend the number of significant figures to which you report a value beyond this as well.

These are just back of the envelope calculations, you can read the altimeter papers if you want, but they illustrate that there’s no reason to suspect fraud in the precision they report.

23. evanmjones says:

If they do it NOAA-homogenization style, they’ll be measuring the naturally uplifting areas and the naturally subsiding areas and then adjusting the former data to match the latter . . .

24. Planck says:

Continental drift has been around for quite some time, causes most sea floor to move, often at millimetres, sometimes centimetres per year. Most of this movement is horizontal but some is vertical. Clearly, the shapes of sea basins are changing continuously.
Surely this movement leads to sea level changes. (Example; try gently squeezing an open plastic water bottle and observe the water level change)
Can anyone tell me just what allowance has been made for these changing shapes? Am I missing something here?

25. Kasuha says:

Come on. If this analysis shows something, then perhaps that sea level rise is accelerating, right?
Or maybe it would be good to take a little better look at the data and figure out what actually happened with them first.

26. Planck says:

I agree with Jim2.
Can anybody plot the I corrected/unadjusted data to compare?

27. James Bull says:

At this rate the earth should be significantly bigger than it was a few years ago!
As everything is rising sea land ocean floor.
James Bull

28. knr says:

Adjustments on their own are not a problem , its the need for justification, the retaining of old data and the tracking of changes that are the problem , especially in the highly politicised ‘climate science’ where often there poor of not seen at all .

But has it the old saying goes , when ‘mistakes ‘ always favour one side its unlikely there ‘mistakes ‘ in the first place .

29. Dave says:

GIA? How realistic are the models? They assume values for the viscosity of the mantle. Whereas his must be infinitely variable in time and space, not least because of the variability in its water content.

30. Ian W says:

MieScatter says:
January 25, 2013 at 3:26 am

osopolitico, sea level is typical measured with a laser altimeter. An example is on the Jason satellite, and the handbook is here:
ftp://podaac.jpl.nasa.gov/allData/ostm/preview/L2/GPS-OGDR/docs/userhandbook.pdf

The error budget shows that an individual measurement expects an uncertainty of the order of cm to ~11 cm.

If I’ve got it right, then that is one measurement. But your uncertainty in measuring an average value gets smaller as you take more measurements.

This claim is only true if the errors are random. If there is any systemic error – a very likely possibility with only one Jason Satellite – then it doesn’t matter how many measures you make the systemic error will still be present. So let us say that there is a slow millimeter a year drift in the satellite measure – that drift will appear as a sea level drift regardless of the number of times you use the laser altimeter.
As long as that drift is in the ‘sea level rise’ direction, confirmation bias will ensure that it is not corrected.

31. Elizabeth says:

I would just love someone here to check HOW NH ice extent has been adjusted over the past 30 years. Just look at those pretty sections they call Arctic Basin , Sea of Laptev sea etc.. ALL these section borders are likely to be moved around to suit the AGW agenda. I actually am convinced that most of the Arctic ice data has simply been made up to suit the data (except the 2007 and 2012 melts (which occur anyway from time to time)
http://arctic.atmos.uiuc.edu/cryosphere/
You see SH ice (Antarctica) doesn’t really change (actually going up slightly) because it does not have any boundary and CANNOT be fiddled with. Please check someone maybe Tisdale and co?

32. NikFromNYC says:

In real science, adjustments are meant to arrive at the true value of something like temperature or sea level, but it is not an “adjustment” to redefine sea level as a virtual entity that does not exist on our real planet. Adjusting for sea floor settling or for retained water in artificial reservoirs on land disallows honest use of the term “sea level” to describe the result. Yet the term is still used to label charts for policy makers.

-=NikFromNYC=-, Ph.D. in carbon chemistry (Columbia U.)

33. jaymam says:

I detest global averages. I’d rather see a global map:
http://stevengoddard.wordpress.com/2011/06/21/record-sea-level-rise-rates/

from which we can see that most of the world has almost no rise, some areas fall, and there’s one bit in the Pacific that allegedly rises a lot and bumps up the global average.
I reckon someone has adjusted the satellite readings in the Pacific where the islands are known to be sinking.

34. Steve Case says:

Thanks for posting my epistle (-:

Actually there’s more. The internet wayback machine
http://archive.org/web/web.php
Has some old pages for Colorado University’s Sea Level Research Group and the oldest is from 2004
The chart on that page shows 2.8 mm/yr. If you go to the oldest time series in the links Anthony posted above
and down load it to Excel and then run the slope you will find that rate of sea level rise 1992 – 2004 is 3.5 mm/yr. Well that includes the 0.3 mm/yr of GIA so it’s really 3.2 mm/yr or 0.4 mm/yr more than originally published. So if you add it all up, 0.4 mm/yr since 2004 plus 0.13 since 2011 and the GIA 0.3 adjustment it comes to over 0.8 mm/yr. So I regard the current 3.2 mm/yr as really less than 2.5 mm/yr which is closer to what the tide gauges tell us.

35. “The science is settled.”
This means that all outcomes of any and all empirical measurements or models made by “The Team” for “The Cause” WILL show CAGW.
Adjustments are necessary when reality defies their “science”.
If the truth comes out, they’re sunk.

36. Gail Combs says:

MieScatter says:
January 25, 2013 at 3:26 am

osopolitico, sea level is typical measured with a laser altimeter. An example is on the Jason satellite, and the handbook is here:
ftp://podaac.jpl.nasa.gov/allData/ostm/preview/L2/GPS-OGDR/docs/userhandbook.pdf

The error budget shows that an individual measurement expects an uncertainty of the order of cm to ~11 cm.
If I’ve got it right, then that is one measurement. But your uncertainty in measuring an average value gets smaller as you take more measurements. It crosses the equator ~25 times per day. I can’t find the sampling frequency, but the resolution is ~4 km. 12.5 full orbits in a day at ~4 km resolution is up to 10,000 measurements per day (assuming all ocean). Let’s say 6,000 to represent unfrozen ocean. The average cycle length at which they report a value is just under 10 days, so about 60,000 measurements per value….
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
But are you (and they) applying the statistics correctly? Are you measuring the same widget 60,000 or are you measuring 60,000 different widgets from different cavities from different molding machines in different factories owned by different corporations?

Bob Tissdale mentions, depending on the strength of the trade winds, one side of the Pacific ocean can be as much as three feet (~ 1 meter) higher than the other side. And then there are the tides. In the Bay of Fundy the difference in water level between high tide and low tide can be as much as 48 feet (14 meters). Then there are waves. In the early 1990s, Ruggiero said, a fairly typical winter might have an offshore wave maximum of a little more than 25 feet.

I really do not think that the sea level rise on a moving body of water can be measured to the degree of accuracy you calculated. The tide waves and wind are all going to introduce error that must be included along with the accuracy of the instrumentation.

37. John Peter says:

MieScatter writes January 25, 2013 at 3:26 am
“The error in the AVERAGE value if an individual measurement has a 10 cm error and you have 60,000 independent measurements would be (in metres) 0.1 / SQRT(60000) = 0.0004 m or 0.4 mm.

Given that the error is of the order of tenths of a millimetre then standard scientific practice is to report the value to tenths of a mm. As it’s an average of many values then it is also common to extend the number of significant figures to which you report a value beyond this as well.

These are just back of the envelope calculations, you can read the altimeter papers if you want, but they illustrate that there’s no reason to suspect fraud in the precision they report.”
So where is the calculation to show that the 10cm error is scattered 50/50 across the 6000 measurements to guarantee an error band of 0.4mm?

38. Another 0.1 mm/year increase in sea level rise!
At this rate UC will be underwater very soon. Is it no underwater now?
They better throw all the bad statistics overboard before their credibility sinks to the very bottom.
Thanks, Steve, Anthony. I have updated the graph in my pages.

39. JCrew says:

A commentor the other day stated WUWT is an opinion blog. For some it has degraded into opinons. And corrupt acts in their work.

40. Don K says:
January 25, 2013 at 2:53 am

Tangentially, does anyone know why they seem to be applying a Glacial Isostatic Adjustment (GIA) to satellite measurements? GIA is necessary and appropriate although not necessarily adequate for tidal gauge measurements where it (partially) corrects for tidal gauges being (slowly) moving platforms. Satellites are moving platforms also, but the satellite motion has already been corrected during orbit determination, and should not, I should think, need additional correction.

One important change in these releases is that we are now adding a correction of 0.3 mm/year due to Glacial Isostatic Adjustment (GIA), so you may notice that the rate of sea level rise is now 0.3 mm/year higher than earlier releases. This is a correction to account for the fact that the global ocean basins are getting slightly larger over time as mantle material moves from under the oceans into previously glaciated regions on land. Simply subtract 0.3 mm/year if you prefer to not include the GIA correction.

I thought I added to that post a gripe that sea level (a dimension of length) now includes an adjustment that is volume (length cubed).

41. AntonyIndia says:

I’ll see your surface temperature adjustments and raise you global mean sea level rise adjustments. Straight faces all around!

42. David L. Hagen says:

VALIDATION: Sea level budget closure
NOAA’s reports it can now close the sea level budget against data.
It evaluates sea level rise at 1.1 +/- 0.8 mm/year for 2005-2012.
The Budget of Recent Global Sea Level Rise 2005–2012
http://ibis.grdl.noaa.gov/SAT/SeaLevelRise/documents/NOAA_NESDIS_Sea_Level_Rise_Budget_Report_2012.pdf

“We apply a model [Paulson et al., 2007] that effectively increases the trend in observed SLmass by 0.9 mm/a. The ice history (ICE-5G) used to produce the GIA model has an estimated uncertainty of roughly 20%. . . .
In this analysis, the global sea level rise budget for 2005–2012 is closed when the Paulson GIA
correction is applied (Table 1). The sum of steric sea level rise and the ocean mass component
has a trend of 1.1 ± 0.8 mm/a over the period when the Paulson GIA mass correction is applied,
well overlapping total sea level rise observed by Jason-1 and Jason-2 (1.3 ± 0.9 mm/a) within a
95% confidence interval.” . . .

Contrast Univ. Colorado’s sea level rate of 3.2 +/- 0.4 mm/yr
U Colorado’s sea level rise rate is only 246% of the NOAA value.

If NOAA’s sea level model rise fits “total sea level rise observed by Jason-1 and Jason-2 (1.3 +/- mm/a) within a 95% confidence interval”, how well does the U. Colorado’s sea level rise rate fit?

Any suggestions as to how to reconcile these differences? (Or is /a only a third of /y – semantics!)

So what’s a factor of 3 between friends?
Isn’t it all in a good cause?!
Or is it only engineers that seek to land in the Sea of Tranquility?
The uncertainty in these other sea level projections might result in ending up on Mars or Venus!

43. Richard LH says:

“The error in the AVERAGE value if an individual measurement has a 10 cm error and you have 60,000 independent measurements would be (in metres) 0.1 / SQRT(60000) = 0.0004 m or 0.4 mm.”

Only really true if the target is stationary and smooth. If there is short vertical motions over time or surface roughness at the sample spacing then there will still be errors in the measurment.

They may well be distributed in a manner different to a normal distribution, so then it is likely that the errors will never truely sum to 0 or even give the precision mentioned.

44. Gary Pearse says:

Anthony, I think it would be good to display on the same chart the tide gauge and satellite data. Watch for a change in strategy soon. Like the temperature data, satellites are constraining the amount of adjustment that can be done on satellite era data so the next step will be to lower the historical data to keep the sea rising rate, or even its acceleration.

45. AFPhy6 says:

Thank you for posting this. I was at the Colorado web site just yesterday looking at this graph, and considered exactly this question. I had not time to search for historical information, but it was at the top of my mind to try doing that, Thanks for doing it and posting it, and saving me a lot of time!

46. Gary Pearse says:

Looking at the new data added to the old, it is suspiciously in 3 equal jumps with little squiggles on each peak. It doesn’t look like the pattern observable on the rest of the graph.

47. Dave says:

This to me seems like it could be a new variation of “Mike’s Nature trick”.

48. KR says:

The 2011 correction has been rehashed before – it is discussed at http://sealevel.colorado.edu/content/addressing-questions-regarding-recent-gia-correction, and was due to an updated measure of glacial isostatic adjustment (GIA). The 2013 adjustment is likely due to (as stated on their home page) “Switched to Jason-2 GDR-D release for all Jason-2 cycles. Updated through cycle 160″.

Better measurements, better sea level rise estimates. If anyone disagrees, show why the science behind the measurements is incorrect, rather than implying or directly accusing folks of fraud.

Mr. Ryan. The only person who used the word fraud was you. That’s the second time this week where a warmist uses the word where the article did did. Projection perhaps? – Anthony

49. Don K says:

“MieScatter says:
January 25, 2013 at 3:26 am

I can’t find the sampling frequency, but the resolution is ~4 km. 12.5 full orbits in a day at ~4 km resolution is up to 10,000 measurements per day (assuming all ocean). ”

————————————–
For the latest satellite, I believe that the sampling rate is 20 samples per second. I’m not sure about the earlier instruments. After allowing for land, ice, and some rejected noise, they presumably get around 1,000,000 measurements a day.

======================
“The error in the AVERAGE value if an individual measurement has a 10 cm error and you have 60,000 independent measurements would be (in metres) 0.1 / SQRT(60000) = 0.0004 m or 0.4 mm.”
—————————————
Surely more like 100 cm+ — waves, tides, water temp, winds, etc
=======================
“you can read the altimeter papers if you want, but they illustrate that there’s no reason to suspect fraud in the precision they report.”
Yes, reading them is a good idea. There are a number of potential error sources not allowed for in your calculations. Satellite orbit errors, attitude errors (the RA may not always be pointed exactly straight down, ionospheric delay modeling, etc).

I don’t think “fraud” is the right term. But “unrealistic” might be applicable.

On top which, I’m pretty sure that the user handbook — while excellent — doesn’t fully explain their methods. It’s about time I reread the thing. But that won’t happen for a few months.

50. Don K says:

Peter says:
January 25, 2013 at 1:09 am

However, i’m sure they reference their data against known surface heights (large salt pans) then use this to correct satellite drift (the adjustment). They must give a reason / data for their correction.

===============================

I’m 98% sure that they use DORIS (a sort of “inverse GPS” network of fixed ground stations) for orbit determination. I think they augment DORIS with GPS, but I may have my satellites confused. Anyway, they know the position of the satellite pretty well. Unfortunately, when you are trying to measure variations in a moving, irregular surface, to a fraction of a millimeter, even very small biases, instrument drifts, and data handling problems can cause problems unless you have VERY long timespans to average over.

51. Darren Potter says:

Is anyone keeping a list of Global Warming scientists (cough, cough) or individuals who have been involved in falsifying data, tampering with data, adjusting data; whether directly or by manipulating measurement methods or calibrations of measurement equipment?

Such a list would be beneficial to organizations looking to hire scientists or individuals of integrity. No organization wants to knowingly hire an unethical person, knowing it could lead to faulty work or litigation for incompetent work.

52. MikeP says:

Altimeters are calibrated to an “absolute” coordinate system through GPS. This was traditionally done with GPS surveyed tide gauges. Salt pans are not used (as far as I know, for sure they didn’t used to be). Even if they were, they’d need GPS measurements to see how they’re moving in an absolute coordinate system tied to the earth..

That’s one issue I have with the GIA correction. It’s taking the measurements back from an absolute reference to being referenced to the sea floor. I can understand why alarmists would be interested in this, but I don’t think it’s appropriate for a primary dataset.

I’m also concerned with recent info from the GPS community that the location of the earth center is not nearly as well known as I thought it was and even worse is not even systematically off. If you can first imagine that the Z coordinate is off, then your value for sea level will also be off because of the N-S asymmetry of the oceans. This wouldn’t matter for trends, but apparently the error is not necessarily constant. So imagine that your best location for earth center is actually drifting N. Then GPS determined locations would have a slow drift and “calibrated” sea level would appear to be rising (even if it were actually not).

The GPS community really, really needs to nail down their coordinate system. Else all precise measurements and calculations based on it will be in error.

53. Don K says:

Ric Werme says:
January 25, 2013 at 5:50 am

I thought I added to that post a gripe that sea level (a dimension of length) now includes an adjustment that is volume (length cubed).

——————————————–
You’re right about the volume correction Ric. And I think that even the CU folks have acknowledged that it’s controversial and perhaps inappropriate. It will, I’m pretty sure, cause observed and satellite measured sea levels to diverge by substantial amounts if it is applied over millennia (e.g. since Roman times). But I somehow got the idea into my head that the volume element was only about 0.03mm per year and there is an additional .27mm per year of GIA in the CU computations that isn’t accounted for. Perhaps I’ve simply made that up. I will add that to my (quite long) list of things to check.

54. Bean says:

Here’s a good review of how sea level is determined with satellites: http://sealevel.jpl.nasa.gov/technology/

Here’s a 15% systemic error that is not mentioned in any measurements: https://c3.nasa.gov/nex/projects/160/

Here’s the real problem that the satellite people must resolve: http://tidesandcurrents.noaa.gov/sltrends/MSL_global_trendtable.html
These are long term sea level trends measured by tide gauge sites around the globe. If you take the average of all 194 sites, there is no trend. These are the measurements that really count as far as coastal communities are concerned. Sea level with respect to the ITRF center of the earth is an academic debate.

55. In my limited understanding, sea level rise means higher low and high tides on every sea-shore on Earth; sea shore property goes underwater.
This depends on whether that sea shore actually is on a sinking or rising continental plate.
If a glacial isostatic adjustment (GIA) correction is used, an extra rise is added to the measurement, a rise that does not happen physically,
one that can not be measured from the ground.
As the ocean basins get larger, the sea level drops; sea shore properties get wider beaches.
Sea level is a proxy for non-floating ice extent; ice over the ground and temperature.
So, it must be kept going up, or the facade drops to the ground.
Thermometer and satellite low-level atmospheric temperatures are going slowly down for the last decade or so.
HADCRUT4 temperature trend since 2002 is now near -0.5°C (-0.9°F) per century.
What gives?

56. Louis Hooffstetter says:

I once worked for a company that built beaches for the US Army Corps of Engineers. If I knowingly submitted fraudulent data to the USACE, it was a felony punishable by loss of my job, a large fine, and possible jail time.

This is a clear example of the same thing. Fraudulent data was submitted to the federal government (NASA) as part of a tax payer funded project. It should be prosecuted exactly the same way. The person(s) who submitted the data should be terminated, fined, and possibly jailed.

57. markx says:

MieScatter says: January 25, 2013 at 3:26 am

osopolitico, sea level is typical measured with a laser altimeter. An example is on the Jason satellite, and the handbook is here:
ftp://podaac.jpl.nasa.gov/allData/ostm/preview/L2/GPS-OGDR/docs/userhandbook.pdf

The error budget shows that an individual measurement expects an uncertainty of the order of cm to ~11 cm.

If I’ve got it right, then that is one measurement. But your uncertainty in measuring an average value gets smaller as you take more measurements. It crosses the equator ~25 times per day. I can’t find the sampling frequency, but the resolution is ~4 km. 12.5 full orbits in a day at ~4 km resolution is up to 10,000 measurements per day (assuming all ocean). Let’s say 6,000 to represent unfrozen ocean. The average cycle length at which they report a value is just under 10 days, so about 60,000 measurements per value.
There are major problems calibrating satellite instruments to our un-cooperative planet, and GRASP will resolve that giving us an accuracy to 1 mm (ie, we don’t have that now):
The baselines between RF/Optical phase centers of all sensors on the supremely-calibrated GRASP spacecraft will be known to 1 mm accuracy and stable to 0.1 mm/year,….

All well and good … but besides the obvious problem pointed out by many in here that repeated measurements of something which varies on momentary, daily, monthly and multi-decadal irregualr cycles, there is also the problem that these laser satellite measurements depend on a calculated TRF (Terrestrial Reference Frame) due to variations, degradations and irregularities in satellite orbits. (as was pointed out previously in an excellent article here in WUWT).

Hence the percieved need for the proposed GRASP mission. (to solve the problem!)

As per below:

At present the TRF is defined through the loosely coordinated networks of four independent space geodetic techniques: Satellite Laser Ranging (SLR), in which ground-based lasers range to Earth satellites carrying suitable reflectors; Very Long Baseline Interferometry (VLBI), in which ground-based radio telescopes make precise angle (or differential range) measurements to distant radio sources; and Global Positioning System (GPS) geodesy, in which groundbased
(and some low orbiting) GPS receivers make precise one-way range and range rate measurements from orbiting GPS sources, and DORIS, in which ground-based beacons broadcast to receivers on Earth orbiting satellites. The current ITRF2005 reference frame has contributions from all four techniques [Altamimi et al., 2007].

Beckley et al. [2007] reprocessed all the TOPEX/Poseidon and Jason-1 SLR & DORIS data within the ITRF2005 reference frame, and found that the differences in the older CSR95 and ITRF2000 realizations and ITRF2005 caused differences of up to 1.5 mm/yr in regional rates of mean sea level rise.

Thus, we assess that current state of the art reference frame errors are at roughly the mm/yr level, making observation of global signals of this size very difficult to detect and interpret. This level of error contaminates climatological data records, such as measurements of sea level height from altimetry missions, and was appropriately recognized as a limiting error source by the NRC Decadal Report and by GGOS. (http://ilrs.gsfc.nasa.gov/docs/GRASP_COSPAR_paper.pdf)

http://ilrs.gsfc.nasa.gov/docs/GRASP_COSPAR_paper.pdf

58. KR says:

Anthony – See http://wattsupwiththat.com/2013/01/24/sea-level-rate-of-rise-shown-to-be-partially-a-product-of-adjustments/#comment-1208537 – my apologies for leaving out the specific reference to “fraud”.

Also _multiple_ comments claiming that these measures are based on manufactured data:
“…not a measured thing, but a figure introduced from outside”
“…the measurements … are being calibrated to radiative greenhouse theory, not anything real on Earth’s surface”
“This year it seems, the data is being made fit for the next IPCC assessment report…”
“Trying to engineer an acceleration to fit the models.”

These are all claims of fraud, whether or not that particular word is used.

I will note that saying “This sort of thing has been going on more or less regularly and it seems to go only one. way.”, without discussing _why_ adjustments are made, or that they might be justified, does leave unpleasant implications hanging for the reader.

59. Anthony, this is similar to your point about malleable history. The revisions to the data plots of the satellites is ongoing. The most egregious adjustments were shortly after they killed Envisat and Jason I. Since then, they’ve only had Jason II to play with, and play with it they have. They regularly change the historical plots with Jason II. If anyone wants to trip down memory lane with the satellite measurements and what they did with the Jason I plots after it quit measuring sea level, you can go here. http://suyts.wordpress.com/2012/09/01/jason-i-the-other-killed-satellite/

The conflation of the data sets is ludicrous. There is no validity to what they’re doing anyway, but, it’s fun to watch them alter history and pretend its some reflection of reality.

60. RobertInAz says:

I would not be concerned about the physics of an individual satellite. Satellite locations are known with great precision. The altimeter will take many measurements of land based locations whose altitude is very precisely known so instrument drift can me monitored and corrected.

There are so many other places between the instrument and the “global average sea level” in which a bias can be introduced. But staying close to the instrument – I would point out that every phenomena that would give an incorrect altitude reading (clouds, planes, ships) all bias the reading in the upward direction. So if there is a significant false negative rate for the rejection algorithm, then that would introduce an “instrument related” bias. And as Dr. Lindzen points out – we are talking about tiny numbers here.

61. Crispin in Waterloo says:

@Robertv

Thanks for that great link to Dr Nils-Axel Mörner’s video on sea levels.

Also ‘nearby’ was Donna Laframboise talking about the IPCC at

Both are 30 minutes long and worth the time.

62. markx says:

RobertInAz says: January 25, 2013 at 8:52 am

I would not be concerned about the physics of an individual satellite. Satellite locations are known with great precision. The altimeter will take many measurements of land based locations whose altitude is very precisely known so instrument drift can me monitored and corrected.

Nope, they don’t measure the TRF with as “great precision” as they would wish. Currently they resort to cobbling together data from 4 different systems, including the GPS satellite system which was not designed for the job. To the extent that the GRACE system has not been as useful as hoped, and to the extent they want a new launch (GRASP) to resolve the problems.

Thus, we assess that current state of the art reference frame errors are at roughly the mm/yr level, making observation of global signals of this size very difficult to detect and interpret. This level of error contaminates climatological data records, such as measurements of sea level height from altimetry missions, and was appropriately recognized as a limiting error source by the NRC Decadal Report and by GGOS. (http://ilrs.gsfc.nasa.gov/docs/GRASP_COSPAR_paper.pdf)

63. The calculation of error to +/- 0.1mm in the “60,000” seal level readings is potentially false because it’s not 1 item measured 60k times, it’s 60k different things measured once each. You cannot reduce errors in the reading by measuring lots of things once. Actually, you can’t actually reduce errors by measuring the same thing lots of times if the measurement system can only measure to +/- 75mm — you just get 60k readings with an accuracy of +/- 75mm.

And of course exactly the same applies to air temperatures. There’s no justification for averaging thousands of geographically distinct thermometer readings to come up with an average temperature quoted to hundredths of a degree. Each individual reading is unlikely to be any more accurate than +/- 1 at best (and the older ones will be worse because they weren’t being taken for the same reasons) given siting issues and UHI effects. The next day’s reading is recording a different temperature, not taking another measurement of the same one, so it cannot increase accuracy. All IPCC temperatures should be given to +/- 1 degree, but then where would they be?

64. Dr. Morners presentation in the linked Youtube video at the top of this thread is priceless…

65. Neil Jordan says:

Re Bjarne Bisballe says: January 25, 2013 at 3:14 am
The approximate 18.6-year cycle has been known for some time as the Metonic Cycle (see below). The cycle is the basis for the 19-year tidal epoch used to define the sea level datum. See American Council of Surveying and Mapping Bulletin at the NOAA website:
http://tidesandcurrents.noaa.gov/publications/Understanding_Sea_Level_Change.pdf

In particular, note Figure 2. “The variation of Mean Range of tide (1900 – 1996) at Seattle, WA, demonstrates the need for averaging the National Tidal Datum Epoch over 19 years.”

In the US, sea level is not just an academic or climate exercise. The various sea level datums, i.e. sea level with respect to adjacent land, are the basis for demarcation between public lands and private lands, historic land grants, and various land ownership boundaries. Quoting from the ACSM Bulletin:

“The importance of a uniform system of tidal datums for all tidal waters in the U.S, its territories, and trusts was recognized and established by the National Tidal Datum Convention of 1980. As a result, NOAA’s definitions of tidal datums—Mean High Water (MWH), Mean Lower Low Water (MLLW), and LMSL—were authorized as the official policy of the U.S. Federal Government.

“Local mean sea level is a term used to denote the average height of the ocean relative to land. Because the ocean surface is dynamic (being influenced by seasonal-to-decadal oceanographic and meteorological processes), we need to use a long period of observations to determine LMSL. The LMSL for the United States is determined as part of the National Tidal Datum Epoch (NTDE) which is based on 19 years.

“Nineteen years is also the length of the Metonic Cycle of recurrence of the lunar phases. This lunar cycle, first determined by Meton of Athens in 432 BC, captures a long-period change in the amplitude of the tide due to the orbital paths of the Earth and Moon relative to the Sun. The Metonic Cycle was selected because it includes daily, monthly, annual, and decadal changes in the amplitude of tides over 19 years.”

66. mpainter says:

John Peter says: January 25, 2013 at 1:08 am

So we have the adjustments to sea levels and the surface temperature records and I wonder what else. What about ocean heat content?

========================
That apparently has been rigged too; Joel Shore recently provided a link to a NOAA chart that showed OHC rising these last fifteen years while SST remained flat. This is blamed on CO2, of course.

67. James at 48 says:

There can be no doubt we are still within the long “coda” related to the Great Melt. That is by definition since we are still in the interglacial. So long as we are still in the interglacial and there is still continential ice in the usual places, this will remain the case. If we see a longer term flattening or God forbid a long term fall … be … very … worried.

68. The GIA at 0.3mm/year, ten percent of the total, is particularly galling because it makes the numbers go up by 0.3mm/year even if every tide gauge in the world stays constant. Because the ocean basins are thought to be getting larger in capacity, it takes 0.3mm/year of additional water just to keep sea level from falling. The U. of Colorado is therefor re-defining sea-level as water capacity, which is perhaps useful if you are trying to account for where all the water in the world is, but it is totally misleading if you are talking about the effect on coastlines and coastal inhabitants, upon which the climate change discussion of sea level is based.

69. gnomish says:

it’s a matter of preserving talking points:
3mm rise per year
vanishing ice caps
shrinking glaciers
drowning poley bears
completely exonerated.

of all these, the best one to take away from them is the last so it is also the best protected.

70. john robertson says:

@KR, If it walks like, talks like and looks like??
Fraud or incompetence?
These systemic adjustments with astounding claims of precision, accuracy and certainty cause you no qualms?
What happened to clearly stating what you know, the precision of this knowledge and the acknowledgement of what is not known?
Infinite adjustments = attenuation of trust.

71. The increase in the slope from 2012_4 to 2013_1 seems to be due to two reasons.

First, we seem to have a real increase in sea level after the decrease seen in 2010.

Secondly, data processing of Jason-2 data has been changed from GDR Version C to D.

2013 Release 1 (2013-01-21):
Switched to Jason-2 GDR-D release for all Jason-2 cycles. Updated through cycle 160.

This change is documented on the Aviso Homepage. We learn that version D has several data adjustments such as

Absolute bias correction
Datation bias correction
Use of GOT 4.8 global tide model instead of GOT00.2
Polar tide anomaly correction
Long period non equilibrium tide anomaly correction

and some more. More interesting is the result of these corrections. Which is, as some might have guessed, an increase in sea level rise.

I have calculated the slope of 2012_4 vs. 2013_1 in OpenOffice Calc. The results are shown in this graph. The data correction has led to an increase in the slope of 0.05 mm/year in 2012 (compared 2012_4 to 2013_1), leading to an total plus of 0,25 mm from 2008 (compared 2012_4 to 2013_1).

Strange thing that. Whatever correction is being made to climate data, it always seems to lead in only one direction.

72. The University of Colorado is remarkably forthright about their re-definition of Global Mean Sea Level (GMSL) as something other than the level of the sea. They write (emphasis added):

This means that if we measure a change in GMSL of 3 mm/yr, the volume change is actually closer to 3.3 mm/yr because of GIA. Removing known components of sea level change, such as GIA or the solid earth and ocean tides, reveals the remaining signals contained in the altimetry measurement. These can include water volume changes, steric effects, and the interannual variability caused by events such as the ENSO. We apply a correction for GIA because we want our sea level time series to reflect purely oceanographic phenomena. In essence, we would like our GMSL time series to be a proxy for ocean water volume changes. This is what is needed for comparisons to global climate models, for example, and other oceanographic datasets.

73. martin_cregg-guinan says:

The University of COLORADO has a sea level study group?

74. Gail Combs says:

martin_cregg-guinan says:
January 25, 2013 at 11:10 am

The University of COLORADO has a sea level study group?
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Yes, it is a hot bed of Climate Scientists. Colorado used to have a really good geology school, the Colorado School of Mines.

75. Peter Howd says:

Nerem reports the UC rate as 3.2 +/- .4 mm/yr in the first plot in the post. The bar chart in the second plot shows all the incremental rates well with the statistical error of that calculated rate, particularly if they are rounded to the same precision Nerem uses. While it is ALWAYS good to question adjustments made to data, they don’t seem to have made a statistically significant difference in this case.

76. Crispin in Waterloo says:

@martin_cregg-guinan
January 25, 2013 at 11:10 am
>The University of COLORADO has a sea level study group?

It is right ‘up there’ with Austria! (a reference to Dr Nils-Axel Morner’s video above).

77. Why aren’t these scammers being arrested? WTF does it take? In any other field, the cops would be all over this by now. Who has the authority to complain to the police or to the FBI or the CIA? Where are they? Is any one of them even sniffing around? Does the MSM have to push for it or something? Do they have to get public approval first? A consensus maybe? Sheesh!

78. Yes, Martin, the University of Colorado is uniquely positioned to study rising sea level because of all the United States, Colorado has the highest lowest point. Every other state will be partially inundated, and 18 states totally submerged before a rising sea pushes the first drops of brackish water up the Arikaree River from Kansas into Colorado, at a minimum elevation of about 3,315 feet. Perhaps that is why they seem so comfortable speaking about sea level as something other than the level of the sea at the shore. For a Coloradan, it is a purely theoretical consideration.

79. Tim Clark says:

{ Gail Combs says:
Yes, it is a hot bed of Climate Scientists. Colorado used to have a really good geology school, the Colorado School of Mines. }

The School of mines is still a very highly rated institution of education. My nephew graduated with a degree in engineering. As others on this site can tell you, it’s difficult to trick a Geologist or Engineer with alarmist hand-waving, but easy to trick a CU tree-hugger. I know from experience, as I attended CSU.

80. Louis Hooffstetter says:

The University of Colorado CU Sea Level Research Group says:

“In essence, we would like our Global Mean Sea Level (GMSL) time series to be a proxy for ocean water volume changes.”

Then call it “Global Mean Sea Volume” instead of “Global Mean Sea Level”, and provide empirical data demonstrating just how much the volume of the ocean basins is increasing due to glacial isostatic adjustment.

The CU Sea Level Research Group is talking out of both sides of their mouths to intentionally mislead the public. They say they want to call it ‘volume change’ but what they really want the public to see, hear, and feel is ‘dramatic sea level rise’ due to AGW.

81. Pat Moffitt says:

A Joint EPA NOAA report for Barnegat Bay (State of the Bay Report 2011) claimed NJ was experiencing “one of the of the highest rates of sea-level rise in the continental United States. The tide gauge at Atlantic City shows a sea level rise rate of increase of approximately 4 mm per year.” The report never mentioned the fact that they were well aware of that a large portion of this relative rise was over pumping of groundwater and the resulting subsidence and compaction of soils.

82. Joseph Murphy says:

It seems fairly clear that they are not measuring sea level but rather sea volume. Their graph is mislabeled and the way they are quantifying it is awkward (mm/yr).

83. Mooloo says:

As I understand it, KR, your position is that the scientists have spoken – and our job is to listen. Excuse us, but we don’t buy that position.

How about you explain why every adjustment is upwards? Even without any knowledge of a subject, that is an overwhelming sign that the answer is being “corrected”. (If you saw a series of corrections in an undergraduate experiment of that nature, it would be pretty much an automatic fail.)

84. Malcolm Miller says:

If you mewasure something with a ruler that is inaccurate, it doesn’t matter how many measurements you make, there will still be an error equal to the error of the ruler. No averaging will correct it.

85. Goldie says:

I’ve been on this planet for over half a century and I’ve always lived near the sea. To the observers eye the level hasn’t changed much at all. These people need to get out more and take a walk by the sea occasionally. Is UC a coastal university?

86. Kip Hansen says:

This shocking exaggeration adds up to: [..wait for it.. ] 0.017 extra inches per year.

If we allowed this travesty to go on for 100 years — that would be a whole 1.7 inches!

Unless dedicated scientific fraud can be proven, this is not worth worry about. Of course, neither is the whole sum of 3.2 (or 3.3) mm a year — which is a whole 0.13 inches.

Beats the heck out of me how anyone can claim to be measuring “The Sea Level” to an accuracy of 0.13 inches under any circumstances.

87. Doug Proctor says:

Since 1992 the GMSL is shown to have risen by 70mm, or 7.0cm. 7.0 cm should be noticeable on all tidal guages. And, as an average, some would have 10 cm. You can’t miss that.

Remember the 21 “high-quality” tidal guages that were used a few years ago to estimate a much slower rate of rise? I wonder that those 21 show …

88. Alcheson says:

In the meantime, all of their “adjustments” keep resulting in values that are increasingly further away from the only important ones that matter…. the tide gauges! You don’t see stories about tide gauges because they DON”T show anything alarming. Soon UoC will be claiming Manhatten is underwater and Hansen has been vindicated. Wonder what the people living in Manhatten will think when they find out they are supposedly living under water.

89. Gail Combs says:

Tim Clark says:
January 25, 2013 at 12:58 pm

The School of mines is still a very highly rated institution of education…..
>>>>>>>>>>>>>>>>>>>>>
You may have had a couple friends of mine as profs. (Graduates of Purdue University who taught at CSM back in the 1970’s) Haven’t seen them in years though.

90. ThePhysicsGuy says:

Tower: “Cesna 456, you are cleared to land on runway 2L”
Cesna 456: “Ah, Tower? There appears to be a communication beacon in our landing flight path”
Tower: “Pay no attention to that. You see, the land around here heaved up 100 feet recently. We’ve made the correct adjustments, so the top of that beacon is actually 100 feet lower than it appears and the runway is also 100 feet lower than it appears. Trust us! Ignore your instruments, we will guide you in.”
___________________________________________________

I wonder if CU consulted with The National Geodetic Survey? Professional surveyors have to be scratching their heads. CU has rendered the term “elevation”, which is a fixed vertical point, into a meaningless quantity.

91. gnomish says:

” In essence, we would like our GMSL time series to be a proxy for ocean water volume changes.”
riiiiiight…
volume is always measured in millimeters

92. john coghlan says:

martin_cregg-guinan……………….exactly

93. David says:

Re, Gail Combs says:
january 25, 2013 at 5:28 am
———————————————————————
Ditto all of your comment, plus, as others said, the tide cycles, some 18 years, some far longer, plus confirmation bias, a nice way of saying corrupted by peer pressure, ( recall how the U of Col SL was virtually flat from 2006 to 2010, then went off line for some time with no explanation, then came back on line with the “new” adjustments.)

If anyone wants to know how accurate the meaurements of the SL are, just google the “Palm Dale Bulge” Years of debate about how much a particular area of a Calif desert have risen due to the San Andreas fault. We are talking about 100s of mm of debate concerning a desert floor, not a rolling liquid surface changing by seveal feet due to atmospheric pressure alone.

94. Dave Richards says:

Not only is the slope of the 2013 rel 1 data steeper than the 2011 rel 1 data, it is also about 9.5mm higher on average. So they have ‘raised’ global mean sea level 9.5mm in two years of processing – actualy most of it (9.2mm) occurred between 2011 rel 1 and rel 2.

95. M Simon says:

MieScatter says:
January 25, 2013 at 3:26 am

You are assuming that what they measure is the “same” . But it varies with time and place. So the noise reduction is less than you estimate. When this was a hot topic a while back the accuracy was estimated in the cm range. IMO – mm range accuracy is doubtful.

Light travels at 1 ft/ns – round trip gives 2ns/ft. So the question is – can the timing be held to better than .2ns? i.e ~1″ ~ 2.5cm? Maybe. But it is difficult.

96. Bill Illis says:

Tide gauges are only showing about 1.0 mm / year of sea level rise.

On average, the tide gauges are uplifting at about 0.3 mms/year according to GPS.

So, sea level rise is only around the 1.3 mms/year rate.

The satellites numbers are adjusted up to what the global warming scientists think should be there from their estimated glacial ice loss and from their estimated steric ocean warming sea level expansion rate.

So, they have just adjusted the satellite rise up to meet the global warming theory assumptions. I’m sure, the satellites are really measuring something in the 1.0 mm/year range (and the ocean is subsiding / deepening at something like 0.3 mms/year so again we are back to the 1.3 mms / year).

Glacial ice loss have grossly overstated due to the inappropriate glacial isostatic adjustment models which have been applied to the Grace gravity satellites. In addition, steric ocean warming expansion is much, much lower than estimated because the oceans are warming much slower than was assumed in the days before the Argo bouys. The global warming scientists are still trying to use the old ocean heat content trendlines which are too high.

It will take some time before the satellite adjusters have to come clean. But in the meantime, you will know what is really happening.

97. Robert Doyle says:

I’ve gained a great deal from Colorado’s web site.
With that positive bias and optimism said, the only ethical rationale ,
[inconsiderate but ethical] for the revisions may be:

As agreement is reached by the Colorado researchers that the model has been improved,
they update the total time series to present a total perspective. Of course, that should
be boldly indicated in the university’s web site.

I’m sure this posting is causing a buzz at Colorado.

Regards,

98. Kasuha says:

I have processed all the data linked in the article. There are no significant differences between them, all the differences are perfectly negligible. The biggest difference is that the last data series is a bit longer than the second to last, and that it shows certain rise in sea levels after several years of stagnation where the second to last series ended.
These data do not show any signs of tampering.

The only problem I can see is lack of scientific approach and a bit too wild imagination of certain people here.

99. John M says:

Pat Moffitt says:
January 25, 2013 at 1:14 pm

A Joint EPA NOAA report for Barnegat Bay (State of the Bay Report 2011) claimed NJ was experiencing “one of the of the highest rates of sea-level rise in the continental United States. The tide gauge at Atlantic City shows a sea level rise rate of increase of approximately 4 mm per year.” The report never mentioned the fact that they were well aware of that a large portion of this relative rise was over pumping of groundwater and the resulting subsidence and compaction of soils.

Not to mention that the rate of rise has been essentially constant for a hundred years.

http://tidesandcurrents.noaa.gov/sltrends/sltrends_station.shtml?stnid=8534720

100. MieScatter says:

Wow, I got a lot of answers to that! I’ll try and get round to some of the points.

M Simon, that level of time measurement should not be a problem. The best atomic clocks are accurate to within something like 0.01 ns per day, and DEMs regularly report precision of well less than a centimetre. My field experience with (much cheaper) terrestrial lidar doesn’t give me any reason to doubt this.

M Simon & Gail Combs; you question whether the statistics of the errors I used are appropriate because the thing changes. I think they are as we’re considering the average sea level height here.

The errors are affected by wave height etc, but that seems to be included in the error budget. The absolute value of sea level at each point isn’t relevant, only the error. The measurement error is typically independent for each sampling, so these are the correct stats to use assuming normal distribution of errors, which I didn’t check. Even if it differs from Gaussian, it would have to be pretty extreme to change my estimate by the two+ orders of magnitude suggested by some on here.

It’s fun to accuse scientists of fraud/stupidity/confirmation bias, but until I see the evidence before me showing that the peer reviewed work on sea level estimation from satellites is grossly wrong then I’m not buying it.

101. M Simon says:

The best atomic clocks are accurate to within something like 0.01 ns per day, and DEMs regularly report precision of well less than a centimetre. My field experience with (much cheaper) terrestrial lidar doesn’t give me any reason to doubt this.

Yes. On the ground. In space? Doubtful. And it is not the accuracy of the clocks I’m questioning. It is their resolution. And the 10 pS per day you mention is not measured. It is computed. What is the RMS noise? It could be as bad as 1 ns for a given measurement although several 100s of ps variation is more likely.

So you have a noisy measurement of 60,000 different samples per day of ocean height. Now just exactly where was the zero crossing? How accurately are the tides accounted for? There are a LOT of things that can confound that height measurement.

My understanding is that it takes 10 years to see a significant difference in height at the current rate of rise.

Making accurate measurements of time is not easy. I discuss this every day on a list.

M Simon & Gail Combs; you question whether the statistics of the errors I used are appropriate because the thing changes. I think they are as we’re considering the average sea level height here.

You don’t measure an average. You compute it.

102. markx says:

Doug Proctor says: January 25, 2013 at 3:34 pm

” ….Remember the 21 “high-quality” tidal guages that were used a few years ago to estimate a much slower rate of rise? I wonder that those 21 show …..”

About 2 mm/year over 100 years, including the 0.3 mm/year GIA adjustment.

The original 24 sites were published as Douglas etal 1997, but it does not seem to be available anywhere … here those24 sites are plotted up to about 2005 on shown on Wikipedia …

103. markx says:

Sorry – mathematical errors below … about 27.5 cm over 200 years (NOT 100 years) = 1.4 mm/year … including 0.3 GIA … so real rise is more like 1.1 mm/year……

Doug Proctor says: January 25, 2013 at 3:34 pm

” ….Remember the 21 “high-quality” tidal gauges that were used a few years ago to estimate a much slower rate of rise? I wonder that those 21 show …..”

About 2 mm/year over 100 years, including the 0.3 mm/year GIA adjustment.

The original 24 sites were published as Douglas etal 1997, but it does not seem to be available anywhere … here those24 sites are plotted up to about 2005 on shown on Wikipedia …

104. Neil Jordan says:

Re Doug Proctor says: January 25, 2013 at 3:34 pm and markx says: January 27, 2013 at 6:52 am
Sea level rise acceleration was covered in WUWT in July 2011 (The battle over sea level in JCR | Watts Up With That?) and again in May of last year:
http://wattsupwiththat.com/2012/05/16/is-sea-level-rise-accelerating/
Two references using tide gauge measurements:
Is There Evidence Yet of Acceleration in Mean Sea Level Rise around Mainland Australia? P. J. Watson
http://www.jcronline.org/doi/abs/10.2112/JCOASTRES-D-10-00141.1
and
Sea-Level Acceleration Based on U.S. Tide Gauges and Extensions of Previous Global-Gauge Analyses J.R. Houston{ and R.G. Dean
http://www.jcronline.org/doi/pdf/10.2112/JCOASTRES-D-10-00157.1

105. David A. Evans says:

MieScatter says:
January 25, 2013 at 3:26 am

Your assumptions are wrong! There is only one measurement a day taken at any given location!
Model away but you can’t eradicate that 11cm potential error.

DaveE.

106. stacase says:

Dodgy Geezer said:
_____________________________

January 25, 2013 at 1:29 am
_____________________________

Yes I did. A while back I asked about the +0.4 mm/.yr variation between their 2004 Release #1 that you can find on the internet wayback machine and that same 1993 – 2004 time series in the current release. I got an answer back that said that they “… cannot point to any specific update that is the main cause of the differences between the 2004 and the current release. But a partial list of the more influential updates include:

– updated orbits
– updated tide models
– updated sea state bias models
– updated dynamic atmosphere

A review of the release notes (http://sealevel.colorado.edu/content/release-notes) shows how we continually apply what the altimeter science community considers to be the most up-to-date set of processing parameters. In fact, the Jason-2 data is currently being re-released and updated to the GDR-D standard, and this will most likely affect the altimeter time series due to these improvements.”

Well what did I expect them to say?

107. Jon says:

It’s obvious that adjustments have been made and that UNFCCC(politics) is to blame?

108. Martin says:

who is Steve Case?

109. Martin says:

nobody knows Steve Case?

110. daveburton says:

markx wrote on January 27, 2013 at 6:52 am, “…= 1.4 mm/year … including 0.3 GIA … so real rise is more like 1.1 mm/year”

That 1.1 mm/year rate of sea-level rise is exactly what I calcuated as both the median and the geographically-weighted average of the sea-level trends at 159 NOAA-selected GLOSS-LTT tide gauges (average record duration of ~85 years).

Dave Burton
webmaster, sealevel.info

111. Neil Jordan says:

NOAA Climate Program Office released “Global Sea Level Rise Scenarios for the United States National Climate Assessment” in December 2012:
http://www.cpo.noaa.gov/Home/Home/AllNews/TabId/315/ArtMID/668/ArticleID/80/Global-Sea-Level-Rise-Scenarios-for-the-United-States-National-Climate-Assessment.aspx
Summary:
“Published December 6, 2012
“Global sea level rise has been a persistent trend for decades. It is expected to continue beyond the end of this century, which will cause significant impacts in the United States. Scientists have very high confidence (greater than 90% chance) that global mean sea level will rise at least 8 inches (0.2 meter) and no more than 6.6 feet (2.0 meters) by 2100.”
[End quote]
Table ES-1 provides the range of the four scenarios of global sea level rise by 2100, from 0.2 m (0.7 ft) to 2.0 m (6.6 ft). From Figure ES-1, the lowest scenario is an extrapolation of measured sea level rise. The other three scenarios presume varying degrees of acceleration of sea level rise assumed to have begin in 1992. The calculated rate for the lowest scenario would be 200 mm in 108 years, or about 1.9 mm per year.