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.
Chris Noble
It doesn’t make any difference to the discussion what the timescale of glass flowing is. If you heat it up a little, it flows faster – just like ice. My comparison was a qualitative one.
http://www.nature.com/news/2005/050516/full/news050516-10.html
Isn’t it interesting that the gigantic glacier which holds 90% of the world’s freshwater is increasing in size. Did the IPCC forget to mention that?
Steve, you keep writing that the ice is too cold to melt at -30C and no one here is arguing that there is surface melting happening. Don’t know why you continue to say there is no mass loss because the temperatures are too cold to melt, no one is arguing with you about that so why continue to try to distract with such statements?
You either seem to not understand that mass loss can happen in many other ways besides melt or you are simply trying to be political. Your entire premise of this article was wrong and purposefully misleading, and a lot of folks have taken their time to point you to references that illustrate the errors in your reasoning. I’m sorry but Chris, Robert and others make a lot more sense than you do.
stevengoddard says:
June 30, 2010 at 10:09 pm
Chris Noble,
Fluid flow is driven by pressure gradients (differences.) Suppose you solve the problem numerically. Let’s say you have a ten metre length of fluid in non-turbulent flow. Break it down into one foot sections.
At steady state, the velocity is constant. (say 1m/sec) Now decrease the downstream pressure slightly. That will cause the speed over the last metre to increase slightly. After almost one second, the fluid at the nine metre mark has moved to the ten metre mark, and the drop in pressure has propagated backwards to the nine metre mark. After almost two seconds, it will propagate back to the eight metre mark, and after almost ten seconds it will propagate back to the other end.
So the time required to adjust to the new pressure gradient is going to be slightly less that the time required for the fluid to travel ten metres under the old pressure regime. If we lowered the pressure at the downstream end by 10%, then the time to propagate the new pressure gradient upstream can be estimated as 90% of the old flow time.
Regardless, it is too cold to melt in East Antarctica and satellite studies show that ice is increasing.
http://www.nature.com/news/2005/050516/full/news050516-10.html
[snip]
_____________________________________________________________
Demonstrating, once again, a total lack of understanding of fluid dynamics, fluid mechanice, and hydrodynamics.
Supercritical or subcritical flow? Pick one.
Closed conduit or open channel flow? Pick one.
I’ll go with closed conduit.
Water Hammer;
http://en.wikipedia.org/wiki/Water_hammer
Did I mention that ONE of my areas of expertise is wave mechanics.
“Regardless, it is too cold to melt in East Antarctica and satellite studies show that ice is increasing.”
Again who says that ice loss in Antarctic is determined by melting? Who? Why do you keep on rehashing this straw man.
PS. Satellite measurements show glacier acceleration and thinning despite your protestations that this is impossible.
http://www.nasa.gov/pdf/121653main_ScambosetalGRLPeninsulaAccel.pdf
Reality does not care what you believe.
Steve, you forgot some other quotes from the study you link to:
In contrast, smaller West Antarctica showed an overall thinning of 0.9 centimetres per year. “It’s amazing that they can measure such small changes,” says Vaughan.
Thick skin
The thickening of the eastern ice sheet should not be seen as a long-term protection against a rise in sea level, warns Vaughan. Glaciers in West Antarctica are accelerating, releasing more and more icebergs into the sea. And the Antarctic Peninsula, which stretches towards South America, now regularly hits temperatures above 0 °C in the summer, leading to direct melting of the ice there.
What’s more, snowfall over East Antarctica will not continue to increase indefinitely in a warming world, Vaughan adds. Conversely, every extra degree of temperature rise will continue to accelerate glaciers and cause more melting on the western side of Antarctica, swelling the world’s oceans further.
Oh and the link of Steve’s also states:
But the panel also expected that climate change would trigger an increase in snowfall over the Antarctic continent, as increased evaporation from the oceans puts more moisture into the air.
The panel being the IPCC panel, so yes Steve, scientists were aware that an increase in snowfall over Antarctica was likely to happen. Geez…why do you constantly, purposefully mis-represent everything?!?
Robert,
you say:
Funny how you choose to ignore the actual basis of the articles and just read the abstracts.
Abstracts are all that are available to us , many retired researchers far away from libraries. It is courteous in net discussions to give links to .pdf’s . Often rogue .pdfs exist on the net of the stuff behind pay walls.
So one is left with your quotes and a lot of imagination.
I will wait for a link that can explain to me, why, when the global geoids show effects as large as the ones seen over antarctica, the explanation for antarctica has to be “ice is thinning” rather than “ice plus ground are moving”. Which brings me to the point that we do not know what ice is doing (except by watching pictures of towers being buried).
To get an answer for antarctica one would have to sound the ground and get an accurate to mm outline of the ground concurrent in time with the measuring of gravity changes, in my physicist’s opinion. Has this been done? in the one paper I have seen, Velicogna,
http://thingsbreak.files.wordpress.com/2009/10/increasing-rates-of-ice-mass-loss-from-the-greenland-and-antarctic-ice-sheets-revealed-by-grace.pdf
no. The problem seems to me is under the rug, err the ice.
“It doesn’t make any difference to the discussion what the timescale of glass flowing is. If you heat it up a little, it flows faster – just like ice. My comparison was a qualitative one.”
If you can’t admit to being wrong about an urban myth then there is very little hope of convincing you of anything.
Your “solid understanding of material behaviour” told you that “In Europe you can see windows which have flowed downwards over hundreds of years.”
Is there anything any expert can say that won’t result in insults and accusation of lies from “Steven Goddard”?
I have seen no evidence of anything else.
“Steven Goddard” – you are obviously a victim of the D-K effect. I will leave you to wallow in your own ignorance, and you can (and no doubt will) insult me at your leisure – but you will be talking to empty air, I’m afraid. You are clearly not amenable to reason, so I won’t waste my time here.
@ur momisugly EFS-Junior
“Conclusion
There is no clear answer to the question “Is glass solid or liquid?”. In terms of molecular dynamics and thermodynamics it is possible to justify various different views that it is a highly viscous liquid, an amorphous solid, or simply that glass is another state of matter that is neither liquid nor solid. The difference is semantic. In terms of its material properties we can do little better. There is no clear definition of the distinction between solids and highly viscous liquids. All such phases or states of matter are idealisations of real material properties. Nevertheless, from a more common sense point of view, glass should be considered a solid since it is rigid according to everyday experience. The use of the term “supercooled liquid” to describe glass still persists, but is considered by many to be an unfortunate misnomer that should be avoided. In any case, claims that glass panes in old windows have deformed due to glass flow have never been substantiated. Examples of Roman glassware and calculations based on measurements of glass visco-properties indicate that these claims cannot be true. The observed features are more easily explained as a result of the imperfect methods used to make glass window panes before the float glass process was invented.”
This is from the link you provided. I’m puzzled that you think it is a convincing final word that supports your contention.
It’s also curious that there’s a general recognition that the bottoms of ancient panes are thicker than the tops and a concomitant willingness to believe that medieval glaziers had the perspicacity to ensure that the end that was half a millimetre thicker went down.
Furthermore, it is thought these feudal artisans oriented the glass in this way because it ensured a tighter seal in the lead cames.
Do we think the leakage through the inversely mounted panes was so apparent that this practice became the approved technique, or was it just an urban myth of the 14th. century? Or maybe it is the more recent product of febrile imaginations looking to offer an explanation for every little detail of a story they’ve written for themselves.
Are you really certain that glass doesn’t sag over the centuries? How about on a mid-summer’s day with the sun shining brightly on the window? What would it take for it to soften just a little and have some saint’s jaw droop just a bit? You have to admit some of those characters look a touch lugubrious.
Ice, of course, unlike glass, flows like honey. At very shallow angles. Flows, not slides. As soon as you remove the chocks. It’s not clear to me what the force was that was holding those chocks in place. Apparently it was greater than the tremendous pressure exerted by 500 km of flowing terrestrial ice.
David
Here is clever idea. How about staying on topic and not spewing ad homs at the author?
I wonder if Steven Goddard read the actual paper rather than just the news report.
The measurements have a spatial resolution of a few hundred kilometers. Indeed the data is passed through a 300km Gaussian filter.
His claim that “GRACE shows ice loss more than 700 km from the coast.” is not supported by the paper.
jeff brown
This article is about East Antarctica, where most of the world’s ice is located.
EFS_Small
Your response was your standard ad hom with zero substance.
The dissonance level on this thread has gone off scale. I’m done here.
It is very cold in East Antarctica. Satellite studies show ice gain. The GRACE data is suspect. Even the suspect GRACE data shows 300,000 years to melt. You trolls have not a leg to stand on, yet argue about every hair-brained idea which pops into your heads.
jeff brown
Sorry one more thing. You argued all day that ice was decreasing, and finish by saying that you and the IPCC expected ice to increase, as it has.
Un-believable. Where did you intellect vandals come from?
It might be useful if Steven looked up the meaning of ad hominem.
“This article is about East Antarctica, where most of the world’s ice is located.”
The scientific papers that you are attempting to refute are about the Antarctic as a whole.
Penal colony in New Zealand, Brad? I think it is you who need a reminder of the history. Still, this seems an appropriate thread for a comment like that.
Robert, sf this one line from Steves post is correct?
“At 100 km³ per year, it will take 300,000 years to melt.”
I only ask as it just makes me wonder why any sane person would be doing the work you do in the intense cold. It also makes me wonder, taking into account the size of Antarctica, the extremely short time so few scientists have studied the place, how you can be so single minded over your (and others) theories.
I, also, find the tone of your posts to be rude. Not something I am used to on WUWT and I have watched many others come on site with a counterpoint argument.
It seems a shame because you obviously know the area well.
Geophysical forward models involving gravimetry such as the data provided by GRACE always have an inherent ambiguity in their solution. For example, ongoing elevation of the dense land surface under the Antarctic land ice will generate an increase in amplitude and decrease in the wavelength of the gravitational potential field signal. An equivalent response could well be generated by land ice loss i.e. ice thinning. Consequently, we have to be very cautious is using GRACE data to conclude that the only cause of the annual change in the gravitational potential field over Antarctica is caused by ice loss. Note, though, I have not done any modelling here, so these statements here as they apply to GRACE data over Antarctica are assertions that require qualification; but we must be very aware that interpretation of gravitational potential field data provided by GRACE to infer ice loss is only one possible solution; it is not the only possible solution.
Everybody should calm down, no meaningful discussion can be head if people take on an aggressive and arrogant tone and call into question the expertise of others. People should be judged on their statements alone, and even then, without insulting them, even if they are claiming the Earth is flat.
As a non-expert, and as the person who first brought up GRACE is a previous thread, I would like this discussion to continue in order to understand whether GRACE measured accelerating loss of ice in the East Antarctica ice sheet is accurate. It seems to me we are all in agreement that West Antarctica is losing ice.
The point of contention seems to be: can calving at the coast bring about mass reductions far inland in reasonalby short timeframes?
Steve argues that is impossible.
He points out that for reductions to be happening via the flow of ice, they would have to be visible all the way up to the coast, not only in small patches inland.
However, it is my understanding that the underground structure of the Antarctica ice sheet is extremely complex. For example, there is a vast network of subglacial liquid lakes and rivers. So much of the movement could be happening underground, where it is not visible. This is my very ignorant take on the situation, so please do correct me if I am wrong.
So point 1): does ice flow fast enough for calving at the coast to bring about melting in the interior? Are there some studies that address this directly?
It seems to me this would be the first thing glaciologists would look into. That ice is extremely viscous and cannot flow fast enough for those reductions to take place inland would be the first thing an expert would know, I’d venture. So I think it is extremely unlikely for this objection to hold value. As a non-expert, I have to rely on experts – when I am sick, I go to a doctor, I don’t search the internet to try to understand my pathology. So on this I’d say Steve is wrong. Unless there is a substantial number of ice experts that agree with him.
I’d say his point on isostasy uncertainty is far more relevant. Fortunately Cryosat 2 just went online. That should soon put to rest any speculation on what is happening to land ice. I hope that if it points to mass losses, skeptics will be ready to accept it. The opposite obviously applies to those who place their trust with GRACE measurements.
2) “Even the suspect GRACE data shows 300,000 years to melt.” I disagree. GRACE shows an acceleration in progress. 26 additional gigatonnes of ice are being lost every year. So the timeframe is shorter than 300k years.
If stained glass windows showed any sign of viscous flow, how much more the lead that holds them in place, when lead is about a billion times less viscous than glass. (See Corning Museum of Glass).
Well Robert, “gone fishing” is a good excuse for self proclaimed experts not answering any questions. The thread will be buried by the time you come back.
Ah, well, I was looking forward to learning how underlying gravity fields could be disentangled from ice changes.
I was thinking in terms of xray lazers from the satellites. There should be reflections from the solid ground that could be mapped. Even if one established the motion in time of a few mountain tops it would be enlightening.
For the non experts, this link is interesting, showing the mountain tops.:
http://lima.nasa.gov/antarctica/ .
Now how can one argue that from such a rough terrain ice from the interior drifts to the coast is a mystery . It looks kinetically trapped by the mountain ranges, to me. Maybe from unobstructed regions it can slide right into the ocean, but most paths look uphill.
Posters seem to be talking past each other a lot here. For example, they keep making arguments appropriate to different parts of Antarctica. The Grace gravitational anomaly map shows significant reductions in Lesser (West) Antarctica. Not Greater (East) Antarctica, where, within the errors, there is no overall change (some regions slightly positive, some slightly negative); so for East Antarctica, where most of the ice is, the evidence is consistent with no change, slight loss or slight gain. For the grounded ice of the Ross Ice Shelf – which is the area Robert’s arguments would apply to – there is Grace evidence of modest net loss, presumably caused by the shelf moving towards the sea somewhat faster. The big anomaly in West Antarctica seems more likely to me to be mainly tectonic – as per Anna’s crit – but may also be consistent with increased calving into the sea, glacial movement, and wind or sublimation loss from the surface.
Steve seems to be relying upon a misunderstanding of the physical mechanism by which glaciers “flow”. Ice is a solid which can very slowly creep. But forget the creep for now; glaciers would still move even if the viscosity were infinite. Imagine a solid sheet of ice, resting on a gradiant of 1 in 100, say; the surface of the sheet has a gradient of say 1 in 200 (flatter than the underlying ground); as we go further inland the ice thickness is progressively less. The ice sheet is moving downslope as a whole at 10m/yr. Assume initially that no ice is either lost from or deposited onto the ice surface. Then, to an observer stationed at any point on the ice, the thickness of the ice shows no change. But, to an observer fixed relative to the ground, the ice thickness is gradually decreasing, by 10m/yr *(1/100 – 1/200) = 5cm/yr. For the glacier to be in equilibrium, there will have to be 5cm/yr net deposition of new ice on the surface (precipitation + frost – ablation – sublimation – melt). If that deposition rate changes, the thickness, and thus gravity anomaly, at a given location will change accordingly. The thickness will also change if the velocity of the ice changes. Let the velocity increase to 20m/yr. Then the thickness will reduce by a further 5cm/yr. The velocity could increase because the pressure at the top is increased (more ice deposited or glacier lengthened) or
the pressure at the bottom is decreased (more rapid calving or penetration of water from the sea) or the ground friction is reduced (more melt water under the glacier or the ice grinding the ground smoother). Because the ice is solid, any pressure change will propagate through the entire sheet at the velocity of sound, which for ice will be a few km/s (water 1.5km/s). For practical purposes, the change propagates instantaneously through the entire glacier; the glacier moves as a block, ever far inland. Real glaciers are more complex, with sheer fractures (crevasses) and velocity gradients, but the principle’s the same; the ice thickness can be affected quite quickly by changes a long way off.