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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Robert says:
“…now can we get back to the part where you admit your analysis was faulty?”
First, I’d like to know how I can get a job like Robert’s — where I can repeatedly write, lo-o-o-o-ng, detailed critiques during my working hours.☺
This may or may not be a salient point, but, if we consider the fact that melting occurs in the antarctic primarily by sublimation into the vapour state, why is a fact of melting amounts then immediately directed to sea level rise? Water vapour in the atmosphere is not water in the ocean until it precipitates.
Robert,
GRACE shows ice loss more than 700 km from the coast. The Science Daily article says “may have begun to lose ice” which implies (unambiguously) that this is a recent event.
Now, using your estimate of 100-500 meters glacial movement per year towards the coast, it would require between 1,400 and 7,000 years to propagate a response 700 km in the interior.
In other words, if the interior of East Antarctica is losing ice, it is in response to changes in ice movement near the coast which occurred thousands of years ago.
I just proved my own point Goddard. See Extensive dynamic thinning on the margins of the Greenland and Antarctic Ice Sheets by Pritchard et al. 2009. Nature Vol 461.
“In East Antarctica, we observe dynamic thinning on some outlets,
particularly between 90u and 165u E (Supplementary Figs 8 and 9).
Thinning of Totten Glacier, the highest-flux East Antarctic outlet, is
three times greater than previously reported28. The similar behaviour
of its smaller, independent neighbours indicates a common, regional
and perhaps ocean-driven cause.”
See Figure 2. You will notice that the coverage is a little sparse in the center because it is laser altimetry but that in EVERY location on your Grace map that shows mass losses in Antarctica, there is thinning occurring in coastal glaciers. This thereby confirms my previous hypothesis that the grace mass loss data is explained by thinning outlet glaciers causing accelerations.
Case Closed.
Robert,
Can we get back to the part where you admit that ice doesn’t melt below 0C, no matter how many times Al Gore or James Hansen repeats it?
http://www.physics.utoronto.ca/news_repository/will-oceans-surge-59-centimetres-this-century-or-25-metres
Smokey says:
June 30, 2010 at 11:39 am
Robert says:
“…now can we get back to the part where you admit your analysis was faulty?”
First, I’d like to know how I can get a job like Robert’s — where I can repeatedly write, lo-o-o-o-ng, detailed critiques during my working hours.☺
Luckily, GIS analysis often takes a lot of time with background processes running and such so one gets some free time while waiting for these procedures to finish. Its nice, well that is if you don’t mind sitting at computers frequently…
JDN: June 29, 2010 at 7:43 pm & Michale Cejnar: June 29, 2010 at 11:13 pm
An interesting concept. I wonder if Anthony and Steven have any opinions on using the law against those that misrepresent the science?
“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?”
Straw man. You very well can’t melt the ice, but the ice isn’t melting at that location, and that’s not what the authors of the paper are claiming. Most of the regular, annual ice loss is due to calving, NOT melting.
“it is too cold over 99% of Antarctica’s ice mass to ever see any melt. ”
Yes, and I don’t think, barring any quibbles over an exact proportion, that the authors, or NASA, or anyone else, is arguing that.
Accelerated ice flow at the ice shelf/terminus would reduce the ice thickness at an upstream location, if accumulation remained constant. It’s like grain flowing out of an elevator and into a hopper – the grain level drops. Warmer ocean waters and terminus surface temperatures certainly can cause accelerated mass loss and accelerated flow, but so can a lot of things, like increased wave action. It’s not so much the melting as it is the mechanical stress on the ice shelf (though meltwater wedging into cracks in the Larson B ice shelf certainly were a factor in its collapse). If you’ve got compressed ice flowing into a terminus, the stress due to expansion is greater in a warmer environment, even if it’s still below freezing. That further undermines the structural integrity of the ice shelf, and can accelerate the calving rate – which controls the flow rate of the ice!
The authors of the paper did not do an attribution study, they just identified and studied the mass balance changes. The locations in East Antarctica that show a negative trend in ice thickness are upstream of their outlet to the ocean. Refer to (http://www.fas.org/irp/imint/docs/rst/Sect16/map+.jpg) for a nice map of flow rates.
“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.”
I agree. The authors of the paper also agree. They removed a number of atmospheric, oceanic, and geologic signals from the GRACE measurements, and took into account post-glacial rebound of bedrock, among other things. They are cautious in their discussion of errors and uncertainties.
I suggest reading the actual paper rather than just the Science Daily article.
Robert
You appear to understand very little about the properties of ice, particularly at extremely cold temperatures.
The viscosity of ice at -30C is extremely high. Imagine an ice cube in the deep freeze that is 700 km long and 3 km thick. Do you think that someone standing at one end of the ice cube will quickly become aware of melting at bottom of the other end?
Again, it would take thousands of years for the opposite end to see any effect.
People who make statements like “case closed” are revealing their lack of intellectual skill and their own closed mind.
“”” jorgekafkazar says:
June 29, 2010 at 8:03 pm
Johannes Rexx says: “You don’t have to melt ice to reduce its quantity. Ice will sublime directly into water vapor when it’s cold enough, the winds are strong enough, and the effect lasts long enough.”
Wrong. Cold ice temperatures reduce sublimation. “””
I believe it is also necessary to have the atmospheric relative humidity be low compared to the saturated vapor pressure at that Temperature. Th esnows of Kilimanjaro for example, are believed to sublime because changes in the forestry on the plains around the mountain; as in cutting the trees down over thousands of years; have resulted in lower levels of humidity in what used to be a tropical rain forest region. So a lack of precipitation on the mountain and low relative humidity up there is why the snows sublime.
Given that that spot in East Antarctica where they now say isce is being lost, is adjacent to a whole lot of ocean water including surface waters that are warmed by tropical currents coming south. So I would not expect that East coast to be so arid, as to promote a whole lot of sublimation from the ice; although some is possible at times, I would suspect.
These sorts of studies seem to be carried out by the same sort of researchers who report that if you cut all four legs off a frog; they are rendered stone deaf; and will not jump, no matter how loud you yell at them.
all this ice has been lost, but as the sea levels havn’t risen by 60m we must suppose it hasn’t melted , so where is it?
Nick Davis
Hansen most certainly is quarreling over that.
http://www.physics.utoronto.ca/news_repository/will-oceans-surge-59-centimetres-this-century-or-25-metres
Most of East Antarctica is considered to be desert, from wikipedia;
http://en.wikipedia.org/wiki/Climate_of_Antarctica#Precipitation
http://upload.wikimedia.org/wikipedia/en/7/7f/File-Dgv-surfbal-1.gif
The total precipitation in Antarctica, averaged over the entire continent, is about 166 mm (6.5 in) per year (Vaughan et al., J Climate, 1999). The actual rates vary widely, from high values over the Peninsula (meters/yards per year) to very low values (as little as 50 mm (2 in) per year) in the high interior. Areas that receive less than 250 mm (10 in) of precipitation per year are classified as deserts. Almost all Antarctic precipitation falls as snow. Note that the quoted precipitation is a measure of its equivalence to water, rather than being the actual depth of snow. The air in Antarctica is also very dry. The low temperatures result in a very low absolute humidity, which means that dry skin and cracked lips are a continual problem for scientists and expeditioners working in the field.”
Looks like desert to me.
Robert,
“Hopefully this helps to clarify your confusion.”
Yes, that makes sense now. Thank you.
Robert
NONE of your “evidence” is solid. All the papers you quote say”may” could” might” its possible”. That is not evidence, it’s guessing.
Can anyone see any substantial Arctic ice loss for June of 2007, 2008 and 2009?
Didn’t think so. But for those who are inclined to panic over completely natural, routine climate fluctuations…
…carry on.
stevengoddard says:
June 30, 2010 at 5:27 am
Robert
Suppose there had of been a recent increase in ice movement near the terminus of the glaciers. It would take hundreds of years for that to be expressed as changes in ice thickness 1000km away, as is claimed in the GRACE maps.
Ice at -30C is extremely high viscosity. If they dig a hole in the ground a mile away from your house, does it change the elevation of your house much?
_________________________________________________________________
Oh there is an INCREASE in ice movement…but it is CAUSED by Volcanoes
Map showing the Antarctic plate (blue) and volcanic activity (red)
“… It is no mistake to call Antarctica a land of “fire and ice,”
…In 1993, a team of geophysicists noticed a round depression, about 6 km (4 miles) wide and 50 m (160 ft) deep. The only thing that could melt so much ice in a round pattern, they reasoned, would be a volcano erupting under the ice. Sure enough, radar revealed a 650 m (2,100 ft) high volcano – sitting in the middle of a huge volcanic crater 8 km (14 miles) wide. Although erupting volcanoes don’t provide nearly enough heat to melt the icecap, they do melt the base of the sheet, providing lubricant for the rapid movement of ice streams and glaciers (see Continental Ice). “
(Thank you for the link Mr. Barry Day)
Nick Davis
The GRACE map shows ice loss 700km from the coast. Do you see any ocean 700 miles in the interior of East Antarctica?
How long do you think it takes a glacier to move 700km to the coast at temperatures ranging between -30C and -80C? You are the one creating the straw man, and it is pretty annoying.
Deal with it. There is no way that the gravity anomaly GRACE shows in the central portions of East Antarctica has anything to do with human influence on the climate or AGW or CO2.
Smokey says:
June 30, 2010 at 1:13 pm
“Can anyone see any substantial Arctic ice loss for June of 2007, 2008 and 2009?
Didn’t think so. But for those who are inclined to panic over completely natural, routine climate fluctuations…”
Funny how you show June and not the sea ice minimum in september. Cherry picking sounds like fun!
stevengoddard says:
June 30, 2010 at 3:14 pm
“How long do you think it takes a glacier to move 700km to the coast at temperatures ranging between -30C and -80C?
Deal with it. There is no way that the gravity anomaly GRACE shows in the central portions of East Antarctica has anything to do with human influence on the climate or AGW or CO2.”
Where is it you see the ice loss in the center of the EAIS. From the figure showed above it is clear that the ice losses are occurring in regions close to the coast and close to the large ice streams which propagate far inland. You still didn’t look at the Allison et al. 2009 article apparently because you would see where the major ice flows are and they correspond with all the mass loss areas on your map. Secondly, no one made the argument that these changes are instantaneous and accelerations could be responding still to the warmth of the 1990s as ice sheets tend to have slow response times. Although this theory has been challenged of late with the instance acceleration of buttressed glaciers feeding Larsen A and B (Scambos et al. 2004).
Finally, the ice at the surface may be extremely cold but don’t you realise that thicker glaciers tend to be warmer at the bottom due to the amount of ice insulating it. Oftentimes thick glaciers create their own basal lubrication because of the insulation at depth. This is also clear based upon the existence of subglacial lakes in certain regions (Glaciers and Glaciation, Benn and Evans, 1998?)
Despite what you say, inland propagation can occur very quickly, especially with grounding line retreats. Evidence for that is shown in Rignot et al. 2005, Scambos et al. 2004, Pritchard and Vaughan 2007, Schoof 2008.
“Goddard says: Can we get back to the part where you admit that ice doesn’t melt below 0C, no matter how many times Al Gore or James Hansen repeats it?”
You still don’t understand how Antarctic ice losses occur. It has nothing to do with surface melt but rather calving and glacier acceleration. Until you acknowledge this any further forays into this topic represents a lost cause on your part.
Robert
Someone says
“NONE of your “evidence” is solid. All the papers you quote say”may” could” might” its possible”. That is not evidence, it’s guessing”
Just because researchers have the foresight to not say things with absolute certainty does not make it guessing. Guessing is what Goddard did with this analysis here. What they did was a large study that gave them an answer and they presented the answer with its uncertainties included. Are they supposed to say its absolutely 100% guaranteed or something? Then you’d be complaining that they are being ridiculously cocky. Secondly, many of the papers do have words like may and such but many also have concrete numbers and detailed measurements. Funny how you choose to ignore the actual basis of the articles and just read the abstracts. Thirdly, you find a way to measure ice changes without any uncertainty! I’m waiting…
Is this a net loss after accounting for any gains?
yet!!! Is this scientific language? Is this a promise concerning Grace’s possible tweaking in future? It’s as if they know what the future will bring. Only time will tell but I think this is a non-story bearing in mind Antarctica sea ice is at a near record high.
http://tinyurl.com/iceup43-nsidc
1980 2009
Sea Ice Extent 3.5 5.0
Sea Ice Conc 2.0 2.9
Case Closed.
I have to go now, on vacation fishing for 5 days. Just gonna summarize a bit. Goddard argued that the pretty close to the coast mass losses (which he calls central? point out the central part on a map??) of ice cannot in reality be real based upon temperatures in the EAIS as a whole. I showed using Allison et al. 2009 paper that fast flowing glaciers in that region actually originate in the coast and are fed by the very regions which Goddard claims have unwarranted losses. I provide the theory that this is due to increased thinning at glacier termini’ resulting in glacier accelerations which increase the mass discharge through the ice streams and thus cause a mass loss in the region. To supplement this, I use Pritchard et al. 2009 to show that the termini for the glaciers to which I referred to and which Goddard referred to, have all showed extensive thinning on their margins. This evidence provided a mechanism through which glacier acceleration could occur. Finally I argued based upon evidence from numerous studies (look at my other posts if you want) that this thinning of glacier termini is the result of warming ocean temperatures eroding away outlet glaciers causing an inland propagation of the surging.
So you can all decide what you like in terms of this argument but it is certainly clear that the evidence supports my conclusions as per other glaciological investigators.