By Steven Goddard,
The headline reads “NASA Satellites Detect Unexpected Ice Loss in East Antarctica”
ScienceDaily (Nov. 26, 2009) — Using gravity measurement data from the NASA/German Aerospace Center’s Gravity Recovery and Climate Experiment (GRACE) mission, a team of scientists from the University of Texas at Austin has found that the East Antarctic ice sheet-home to about 90 percent of Earth’s solid fresh water and previously considered stable-may have begun to lose ice.
Better move to higher ground! NASA also reported :
In 2007, NASA generated this map (below) of Antarctica showing just how hot it is getting down there in the land of Penguins.
Now I am really worried! But wait……. There are a few minor problems.
Assume for a minute that we accept the GRACE numbers. The first problem is Antarctica contains a lot of ice : 30 × 10^6 km³. At 100 km³ per year, it will take 300,000 years to melt.
The next problem is with the NASA temperature map. From the NASA article “The scientists estimate the level of uncertainty in the measurements is between 2-3 degrees Celsius.” They are claiming precision of better than 0.05°C, with an error more than an order of magnitude larger than their 25 year trend. The error bar is large enough that the same data could just as easily indicate rapid cooling and blue colors. That will get you an F in any high school science class.
And that is exactly what happened. The hot red map above was preceded by a cold blue map which showed Antarctica getting cooler. What motivation could NASA have had to change colors without mathematical justification?
NASA justified their heating up Antarctica with this comment :
This image was first published on April 27, 2006, and it was based on data from 1981-2004. A more recent version was published on November 21, 2007. The new version extended the data range through 2007, and was based on a revised analysis that included better inter-calibration among all the satellite records that are part of the time series.
As I have already pointed out, this is absurd. Their error bar is so large that they could have painted the map any color they wanted. Apparently someone at NASA wanted red.
But why are we looking at temperature trends anyway? The real issue is absolute temperatures. Some of the regions in which GRACE claims ice loss in East Antarctica average colder than -30°C during the summer, and never, ever get above freezing. How can you melt ice at those temperatures?
http://en.wikipedia.org/wiki/File:Antarctic_surface_temperature.png
I overlaid the Antarctica summer temperature map on the GRACE “melt” map, below. As you can see, GRACE is showing ice loss in places that stay incredibly cold, all year round.
The problem with GRACE is that it measures gravity, not ice. Changes in gravity can be due to a lot of different things beneath the surface of the ice. Antarctica has active magma chambers. Plate tectonics and isostasy also cause gravity changes.
We should be clever enough not to be blinded by technology. The claims that ice is melting in East Antarctica don’t have a lot of justification.
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http://www.wunderground.com/global/stations/89009.html
goddard says,
“Published online 19 May 2005 | Nature
East Antarctica puts on weight
Increased snowfall over a large area of Antarctica is thickening the ice sheet and slowing the rise in sea level caused by melting ice.
A satellite survey shows that between 1992 and 2003, the East Antarctic ice sheet gained about 45 billion tonnes of ice ”
Oh come on Goddard, that’s an old paper which uses an old method that has been shown to overestimate mass changes. Since that time there has been a plethora of studies which show clearly that Antarctica is losing ice. These studies include, Chen et al. 2006, Rignot et al. 2008a,b, Cazenave et al. 2009, Velicogna 2009, Chen et al. 2008, Allison et al. 2009, Pritchard et al. 2009, Gunter et al .2009… the list goes on. Do you know there hasn’t been a single study using laser altimetry, grace or radar interferometry that has put a positive mass balance on Antarctica. There’s a reason for that.
Your example is using radar altimetry which has a bias towards overestimation of ice gains in regions which are sloped or on smaller glaciers cause of its low resolution.
“Radar altimeter signals
penetrate the near-surface snow and ice layer, and the
results can be affected by the internal structure.
Satellite-borne radar altimeters have a relatively large
footprint (2–3 km), which can lead to a bias over
rough or sloping terrain, and challenge measurement
accuracy in narrower outlet glaciers.”
Allison et al. 2009
People always drag out that study and yet its so easy to refute because laser altimetry is MUCH MORE ACCURATE and show losses. Radar interferometry shows accelerations leading to more losses and GRACE shows a mass loss. Your point is moot and without scientific merit. The glaciological community does not even use old radar altimetry anymore because of these biases. We have been waiting for the new cryosat-2 to start gathering data because of its higher resolution radar altimeter.
Now please, don’t drag out that study anymore unless you have a means of defending the results. Notice the authors of that study have since been collaborators in my previously mentioned studies…
Last winter, temperature at the South Pole hit -106 degrees and the last time I looked, the average annual temperature in Antarctica was -58 degrees. That means in order to melt any ice, the temperature must rise 58 + 32 degrees = 90 degrees just to get to the melting point of ice. I don’t think the Antarctic ice sheet, which is well over 10,000′ thick, is going to melt at these temperatures.
West Antarctica is surrounded by ocean water, which has warmed during the 1977-1998 warm period, and has caused minor melting, but that’s a totally different story than the main continental ice sheet which lies well to the east and shows no signs of melting.
We know there is liquid water beneath the Antarctic ice: Lake Vostok for example. So, the whole premise of this post is wrong.
The very NASA article that “Steven Goddard” links to explains how ice can be lost without surface melting. The very question that so confuses him is answered already!
Secondly, uncertainty in absolute measurement isn’t the same as uncertainty in relative changes. This is a well-known situation in measuring temperature, where we can’t be sure of the exact temperature, but we can measure changes (or anomalies) with great precision.
Anthony Watts, this isn’t the first post by “Steven Goddard” displaying a woeful lack of regard for basic research or fact-checking. Continuing to post his “insights” will damage your credibility. Does this concern you?
“this is astonishing”, “this is incredible”, “it’s absolutely criminal”, “where do these people come from”, “lies, lies, lies”, “NASA’s a joke”, “this isn’t science”, “this is political, it’s NOT science”…….
Sure sounds like people are beginning to wake up. Wonder what’s going to happen when we realize the truth of what was going on while we were asleep in bed with visions of sugar plums dancing in our heads? The bigger government becomes, the harder it is to keep it in check. Eventually it reaches a critical mass and becomes a runaway, out of control, no stopping it, etc., etc., …. (the more we want, the more we’re going to pay –or– the less we watch, the more we’re going to lose –or– there is no autopilot for life, liberty, and the persuit of happiness).
To Robert & David,
It’s comfortable taking pot shots against Steve Goddard from the sidelines, isn’t it? So let’s see you both man up and write your own articles like Steve does. Show us how either of you withstand drive-by criticism.
Robert,
You used an interesting phrase in your last post – “is using radar altimetry which has a bias towards overestimation of ice gains in regions which are sloped”
You do understand the difference between “gaining” ice and losing ice?
Robert,
Again, you wrote “overestimate mass changes”
Overestimation is a completely different concept from having the wrong polarity.
Methinks you are being extremely intellectually dishonest.
Robert,
One more point re your dishonest posting.
This article is about East Antarctica, and you are referencing studies and data which include West Antarctica.
anna v,
Thanks (again) for your contribution and insight here. I’ve learned much truth/facts from you. Noticed you were missing for a period of time back a few months ago and were hoping you were okay, what with all the “problems” there in Greece.
Your observation – Seems to me there must be a policy decision to push the AGW panic button on all fronts. is spot on. The Obama administrations Department of Politics & Propaganda is burning the mid-night oil – (well, they have to do something with all that oil gushing up in the Gulf) and they are damn good at it. Unfortunately, it’s 1 of ONLY 2 things the administration is good at. The other is being TOTALLY inept at everything else – – well, there is 1 other thingthey’re great at, but let’s not get into personality disorders.
@ur momisugly Robert “Lets see your evidence countering mine?”
I don’t see he has to provide any evidence countering yours – the “evidence” you provide is merely conjecture.
Firstly, if the ice is reaching the ocean faster, why would the absolute temperature make any real difference? The ocean is significantly warmer then the melting point of the ice and therefore ANY ice at ANY time reaching the ocean will be forced to melt – this is always going to be the case regardless of its absolute temperature. Secondly, even if the ice in glaciers close to the ocean were to melt entirely the ice further inland will not readily reach the sea since it is effectively locked to the terrain beneath it. Finally, if the ice on the glaciers has been flowing to the sea for some considerable time then you need to explain why the glaciers are still there at all given that actual precipitation is very low in Antartica (of course you don’t actually need precipitation for ice to form).
Realistically, how can there at once be glaciers in the Alps whilst simultaneously claiming that glaciers in Antartica are melting at a dramatic rate.
Robert,
you make some interesting technical points. However, I’ve always taken ice extents from cryosphere today, and they show a positive anomaly for the SH. Yet you seem to be claiming the opposite.
David
A claimed trend of 0.03-0.05C per year with an error of 0.12C per year is meaningless. Particularly when the same organisation was previously showing a trend of -0.1C per year in the same region.
In fact, it is complete nonsense.
David
Does it concern you that you are defending unsupportable positions?
Is the paper claiming accelerated melting? No, it’s claiming accelerated mass loss.
Ice loss in Antarctica is primarily due to calving at the terminus of the ice flows – on the order of 95%+ of all ice mass is lost by ice breaking off and forming icebergs. Very little of the annual ice loss in the Antarctic is due to melting, and this occurs in only a few locations.
Temperature does influence this process. Warmer water can undermine the integrity of the ice tongue, and cause accelerated calving. Warming temperatures in the accumulation zone of the glacier, as long as they are still below freezing, can increase the annual accumulation rate – which can go into accelerating the ice flow, or increasing the ice sheet thickness, or a bit of both. So temperature anomalies, depending upon location, can lead to increases or decreases in ice mass.
Please understand that glaciers and ice sheets lose mass in below freezing temperatures – tidewater glaciers like Columbia Glacier still lose ice in the winter, as do the Greenland and Antarctic ice sheets.
I would urge readers of this blog to pick up or rent a copy of The Physics of Glaciers if they are interested in an in-depth discussion of glacier processes. This video (http://courses.washington.edu/ess431/Pictures/VG83_main_stream_arrival_Mpeg4_u1.mov) of Variegated Glacier will give you an idea of how fast these rivers of ice can move. Granted, Variegated Glacier is a surge glacier, but ice moves on the order of kilometers per year in some flows on these ice sheets. Jakobshavn Isbræ comes to mind.
stevengoddard says:
June 30, 2010 at 6:58 am
Robert,
One more point re your dishonest posting.
This article is about East Antarctica, and you are referencing studies and data which include West Antarctica.
Perhaps the original poster should have confined his discussion to East Antarctica then?
Goddard,
i made a mistake in the way I wrote that statement. Radar altimetry has a bias towards more positive mass balance measurements is the correct way it should have been written. Once again, I refer you to Allison et al. 2009 for confirmation that it was just an error in sentence structure. Radar Altimetry does in fact have a bias towards more positive values because altimeter mode is downward facing which results in a lower resolution swath. Angled radar such as used in radar interferometry, counterintuitively has a much greater resolution all to do with the way the signal reaches the ground and so on.
The result is that radar altimetry overestimates positive mass changes on sloped regions such as the Antarctic Peninsula. And the other result is that radar altimetry’s low resolution (2-3 km) doesn’t identify individual basin level changes. For example a small glacier can lose much more ice than its surroundings but because of the low resolution data, the glacier losses are smoothed out. Once again, you can look this up yourself if you think i’m being “intellectually dishonest” but the truth of the matter is that you were nitpicking my own sentence errors because you could not refute the overwhelming science I presented.
Smokey says:
June 30, 2010 at 6:39 am
“To Robert & David,
It’s comfortable taking pot shots against Steve Goddard from the sidelines, isn’t it? So let’s see you both man up and write your own articles like Steve does. Show us how either of you withstand drive-by criticism.”
Look, I don’t step into the fray a whole lot here because there are some articles I really enjoy but it was clear from the outset of this article that Goddard did not adequately research the literature or understand how Antarctic mass changes are occurring and what are the primary drivers behind these changes. It is not hard to find the accurate information pertaining to the region but yet it is clear that he did not attempt to do so.
He essentially questions Grace mass anomalys based upon the idea that no melting is occurring but yet ignores that the overwhelming majority of ice changes in Antarctica are due to accelerations of glaciers and increased ice discharge. That doesn’t fly with. If you’re going to make a post, you have to take the time to research the subject.
David Smith says:
June 29, 2010 at 7:56 pm
When the time comes to cut American government spending, and that time is coming, I know a bureau and a university which are deserving candidates for cuts.
__________________________________________________________________
How about the WWF who recieves 20% of its funding from government
“World Wildlife Fund financial condition June 30 2001: Government Grants $24,589,994 “
I would like to see most government spending cut to the bone and most of the bureaucracy and pork cut. I would also like to sef lobbying and campaign contributions by activist groups, corporations or foreigners made illegal. I thought we were supposed to have a government by the people for the people not a government by the corporation for the corporation.
I would also like to see the “read the bill law” passed.
Goddard,
pertaining to your criticisms of those studies being on Antarctica as a whole, Rignot et al. 2008a calculated ice losses for both the EAIS and WAIS and conclude that the EAIS is slightly negative. Velicogna 2007 concludes that it is in balance, but Chen 2009 (another one i forgot to mention) is the most recent study and shows that since 2006 the EAIS has been losing ice extensively at -57 Gt per year. Based upon my assessment of the literature, the EAIS was in balance or slightly positive during the 1990s, balance or slightly negative during the early 2000s and extremely negative since the early 2000s. This goes hand in hand with thinning occurring on cook and totten glaciers in EAIS according to Shepherd and Wingham 2008…
You can accuse me of intellectual dishonesty all you want but I have made a legitimate effort to prove my case and to show that the literature and evidence supports my conclusions. Where is your evidence? I think that until you research a little bit more into this subject you should stick more to your specialties.
David says:
June 30, 2010 at 6:12 am
“Secondly, uncertainty in absolute measurement isn’t the same as uncertainty in relative changes. This is a well-known situation in measuring temperature, where we can’t be sure of the exact temperature, but we can measure changes (or anomalies) with great precision.”
David: It is also true that the variation of changes can range all the way from zero (the best case for precision) to being equal to the pooled estimate of the variation of the original measures which gave rise to the computed change. Also, in any statistical comparison, the sample size associated with the test statistic, which is used to calculate degrees of freedom for the comparison, is 2xn for the raw data and only n for the change data. One must have all of the raw data in hand before any conclusion about “precision” and the effects of using “changes” can be reached.
Robert,
Looking at the mass component of sea level rise as determined from Grace, I assume that the effect is primarily due to ice loss from Antarctica where 90% of the land ice is.
http://www.argo.ucsd.edu/global_change_analysis.html#temp
However, the graph from the above ARGO site clearly shows that sea level rise from positive mass gain is in the fall when I assume that the glaciers in antarctica are likely surging after gaining weight from the polar winter. In the spring at the end of the polar summer there appears to be a drop in sea level or a mass gain on the continent?
It seems to me that surging glaciers is not a sign of retreat due to warming seas but rather due to increased mass developed over the polar winter. Can you explain?
Robert and David,
Do you have a link of a study/proof of the stability ind time of the underlying planetary gravitational fields?
This is my third post where I stress that measuring differences in height and accelerations of these differences may have a gravitational input G1 from diminishing ice, and G2 from isostatic changes because of diminishing ice, but what is being quoted ignores G3, which is the field coming from the bulk planet, huge in mass with respect to the surface effects measured, and where we know there are tectonic and magma motions that move masses and change densities that are much higher than the density of H2O as ice.
I have not seen anybody addressing this problem, of too many unknowns for the data given. What is coming out of the fits is G1+G3, and I see no way of disentangling them except hand waving.
That G3 is large is evident in the geoid given by GRACE, http://earthobservatory.nasa.gov/Features/GRACE/page3.php where changes are not isolated on the antarctic.
A truthful analysis would be to give the maps for the whole globe, not interpreted as ice, but as gravitational changes. There is no physics reason that gravitational changes will be isolated in the other tectonic plates and leave the antarctic plate to play with the ice only.
So before flooding us with more of the same behind pay wall references, why don’t you give a link where this gravitational question is explained?
This is outright falsehood, FTA:
“..that the East Antarctic ice sheet-home to about 90 percent of Earth’s solid fresh water and…”
Uh, no. Antarctica as a whole is home to about 90 percent of Earths’ solid fresh water, not just the east side. The way this was phrased it cannot be excused as bad wording, that’s a lie.
Steve, I’m afraid you are the one who did the dishonest reporting in this article. David and Robert are correct.
I also believe you understand the factors behind changes in mass balance of glaciers and ice sheets but purposely chose to ignore those in order to once again try to discredit any science showing loss in the mass of ice on the planet. From your incessant use of PIPS2.0 it is clear that you only believe in science or models when it suits the point you are trying to make. The reality is there are declines being observed in ice on the planet no matter how hard you try to mislead others less well read on the subject.