This is quite interesting. Remember the claim in on the front cover of Nature in 2009 by Steig and Mann that Antarctica was warming, thanks to that “special Mannian PCA math sauce” that was applied to air temperature data to smear surface temperature trends over the entire continent? It was dashed by climate skeptics who wrote a paper. It was accepted for publication and disproved (in my opinion) by a team of credible skeptics that wrote a counter-paper. But, there’s an interesting twist thanks to new and surprising data; Steig and Mann may have captured surface air temperature trends in the exact same areas that have been identified as geothermal hot spots.
First the press release, from the British Antarctic Survey on Nov 13th, 2017:
New Antarctic heat map reveals sub-ice hotspots
An international team of scientists, led by British Antarctic Survey (BAS), has produced a new map showing how much heat from the Earth’s interior is reaching the base of the Antarctic Ice Sheet. The map is published this week (Monday 13 November) in the journal Geophysical Research Letters.
The team has produced the most up to date, accurate and high-resolution map of the so-called ‘geothermal heat flux’ at the base of the Antarctic Ice Sheet. Of the basic information that shapes and controls ice flow, the most poorly known about is this heat.
The data used come from magnetic measurements mainly collected by aircraft flying over the continent and the results reveal the ‘hot spots’ under West Antarctica, (West Antarctic Ice Sheet WAIS) and on the Antarctic Peninsula. These areas are the most rapidly changing areas of the Antarctic Ice Sheet.
Lead author, geophysicist Dr Yasmina Martos who completed the work at BAS says:
“This new map of heat escaping from inside the Earth will help advance our understanding of the conditions at the base of the ice sheet, improving our ability to understand the past and to project future changes of the Antarctic Ice Sheet and its impact on global sea level”.
Co-author BAS geophysicist Dr Tom Jordan says:
“It is incredibly difficult to take direct measurements of heat from the Earth’s interior beneath 3-4 km of ice in extremely cold and hostile conditions. That’s why we have used magnetic data to infer the heat and we’re pleased that what we have is 30-50% more accurate than previous studies.”
The Antarctic Ice Sheet contains the largest reservoirs of fresh water on our planet – around 70% of the world’s fresh water – and is currently losing ice, which contributes to rising sea levels.
BAS Science Director and glaciologist Professor David Vaughan says:
“If we are to predict with any certainty the future response of Antarctica in a warming world, scientists need to understand the role that heat from the Earth plays. What we know is that over time, the heat flow into the ice is quite constant and so the ice sheet adjusts to it. The ice loss we’ve seen in recent decades is actually the result of changes in air and ocean temperatures. How the ice sheet will respond to these recent changes is influenced by the pattern of geothermal heat, and that’s why this new map is so important”.
###
The paper:
Heat flux distribution of Antarctica unveiled by Yasmina M. Martos, Manuel Catalan, Tom A Jordan, Alexander Golynsky, Dmitry Golynsky, Graeme Eagles, David Vaughan is published in Geophysical Research Letters here:
http://onlinelibrary.wiley.com/doi/10.1002/2017GL075609/abstract
Abstract
Antarctica is the largest reservoir of ice on Earth. Understanding its ice sheet dynamics is crucial to unraveling past global climate change and making robust climatic and sea level predictions. Of the basic parameters that shape and control ice flow, the most poorly known is geothermal heat flux. Direct observations of heat flux are difficult to obtain in Antarctica, and until now continent-wide heat flux maps have only been derived from low-resolution satellite magnetic and seismological data. We present a high resolution heat flux map and associated uncertainty derived from spectral analysis of the most advanced continental compilation of airborne magnetic data. Small-scale spatial variability and features consistent with known geology are better reproduced than in previous models, between 36% and 50%. Our high-resolution heat-flux map and its uncertainty distribution provide an important new boundary condition to be used in studies on future subglacial hydrology, ice-sheet dynamics and sea-level change.
Now some recap of what claims were made about Steig et al. in 2009:
Steig stated in the New York Times in December 2009:
“We now see warming is taking place on all seven of the earth’s continents in accord with what models predict as a response to greenhouse gases.” Source: http://www.nytimes.com/2009/01/22/science/earth/22climate.html?ref=science
Drew T. Shindell of the NASA Goddard Institute for Space Studies in New York, co-author of the paper, said:
“It’s extremely difficult to think of any physical way that you could have increasing greenhouse gases not lead to warming at the Antarctic continent.”
Ummm, well it’s not all that hard to imagine if you think that the part of Antarctica with the most volcanic activity under the ice might also have the greatest amount of heat release. 91 such volcanoes have been discovered thus far:
Wikipedia has this to say about it follow on studies to Steig et al 2009:
In early 2013, David Bromwich, a professor of polar meteorology at Ohio State University, and a team including Antarctic weather station experts from the University of Wisconsin, published a paper in Nature Geoscience showing that the warming in central West Antarctica was unambiguous—and likely about twice the magnitude estimated by Steig et al. The key to Bromwich et al.’s work was the correction for errors in the temperature sensors used in various incarnations of the Byrd Station record (the only long record in this part of Antarctica); miscalibration had previously caused the magnitude of the 1990s warmth to be underestimated, and the magnitude of the 2000s to be overestimated. The revised Byrd Station record is in very good agreement with the borehole temperature data from nearby WAIS Divide.[24] A new statistical reconstruction[25] shows significant warming over all of West Antarctic in the annual mean, driven by significant warming over most of the region in winter and spring. Summer and fall trends, are insignificant except over the Antarctic Peninsula where they are widespread only in fall. These finding are in good agreement with the 2009 study in Nature, though in general the new results show greater warming in West Antarctica and less warming over East Antarctica as a whole.
Source: https://en.wikipedia.org/wiki/Antarctica_cooling_controversy
Yes there’s warming in West Antarctica and the Peninsula, but is CO2 the cause? This new geothermal heat flux data and study from BAS throws ice water on that idea.
The new study from BAS uses over 50 years of magnetic measurements that were collected from thousands of hours flying over the continent. Warmer rocks lose their magnetic properties, and so the team was able to use the loss of magnetism in certain areas to calculate an estimate of the geothermal heat flux.
And gosh, side by side, these two maps look strikingly similar in the “hot spot” areas on the Antarctic Peninsula, and West Antarctica:
Steig and Mann, despite their failed attempt to use warming in one area of Antarctica to infer warming over the entire continent may have in fact captured an air temperature signature from that heat flux, which is completely unrelated to “climate change” or “global warming”.
I predict a new paper will correlate these two previously unconnected datasets, followed by much wailing and gnashing of teeth from climate scientists who will still insist the warming in Antarctica is a “robust” indicator of global warming.
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Reading this article prompted a few questions I don’t know enough to answer:
The red dots on the second map of Antarctica show the volcanoes are all pretty much near the coast of West Antarctica. Are all the volcanoes really near the coast, or does their method have difficulties detecting inland volcanoes where the ice is thicker? It just seems odd that they cover such a wide area but only near coastal regions.
“What we know is that over time, the heat flow into the ice is quite constant and so the ice sheet adjusts to it.”
— Professor David Vaughan
How do they know the heat flow is constant? Have they been measuring the heat flow long enough to determine that? And how does an ice sheet “adjust” to the heat flow? Can an inanimate object like ice change its melting point or adapt to its environment?
Past articles on West Antarctica expressed concerns that global warming would cause melt water to flow underneath the ice sheets, lubricate the bottom of the ice, and cause them to slide out to sea at an alarming rate. (Everything happens at an “alarming” rate when it comes to climate change.) But wouldn’t volcanic activity be more likely to create this problem by causing melt water to puddle underneath the ice sheets where they contact the heated ground?
Yes
“It just seems odd that they cover such a wide area but only near coastal regions. ”
It’s the southern rim of the Ring of Fire, so it makes sense that they occur in a coastal band like virtually everywhere else in the Pacific.
Capitols add be me.
Why are we using always “relative” instead of “absolute” numbers?
The Ice melt at 0°C or at variations of, says, -2°C?
36 to 50% of PREVIOUS has same significance than say: “I don’t see you from the last time we met!”
If the previous model was 1% accurate, the new one is 1,36 to 1,50% accurate.
And if the previous model was 90% accurate, the new one is 122,4 to 135,0% accurate. More accurate then the reality!
I beg your pardon for my bad English.
“Than” not “Then”. Sorry.
Basically geothermal heat flux can, and probably does, affect glacier dynamics since warm-based glaciers move much faster and have shallower profiles than cold-based. However it is much too small (<<1 Wm^-2) to affect air temperatures above the ice (well, possibly just a little bit in deep winter and with no wind).
However the West Antarctic “warming” is probably mythical in any case. The Wikipedia quote is significant in this regard:
“In early 2013, David Bromwich, a professor of polar meteorology at Ohio State University, and a team including Antarctic weather station experts from the University of Wisconsin, published a paper in Nature Geoscience showing that the warming in central West Antarctica was unambiguous—and likely about twice the magnitude estimated by Steig et al. The key to Bromwich et al.’s work was the correction for errors in the temperature sensors used in various incarnations of the Byrd Station record (the only long record in this part of Antarctica); miscalibration had previously caused the magnitude of the 1990s warmth to be underestimated, and the magnitude of the 2000s to be overestimated.”
The Bromwich paper is a classic case of one-sided “adjustment” to get the result you want. They found a temperature sensor error that caused a cold bias, though mostly in summer. However they did not correct for another well-known (and much larger, up to >10 degrees C) warm summer bias for this kind of unventilated sensor due to solar heating:
http://journals.ametsoc.org/doi/full/10.1175/JTECH-D-11-00095.1#
Bromwich et al argued that this was unnecessary because West Antarctica is windier and cloudier than East Antarctica. However one wonders in this case why they didn’t adopt the simple remedy recommended in the paper above and discard summer data where the wind was less than 6 ms^-1. The answer is that Byrd station isn’t that windy in summer. The average wind is actually about 6 ms^-1, suggesting that something like half the summer measurements are warm-biased. The argument about cloudiness is also weak since the effect is significant down to a solar irradiation of about 200 Wm^-2, i. e. less than 25% of full summer irradiation in Antarctica.
Solar heating doesn’t cause a warming bias (as opposed to warm bias), unless the temperature sensors and shields are replaced with new equipment that is more sensitive to solar heating.
However, the technical development usually leads to instruments that are less sensitive to spurious solar heating, which uncorrected would result in a cooling bias when instruments are updated.
This applies to both temperature sensors on the ground and radiosondes carried aloft by weather balloons, and is the simple explanation why homogenization of temperature data commonly leads to increased temperature trends
And by the way your touching faith that new sensors are always better than older ones is not supported by experience, e. g. the ASOS debacle.
It does in this case. Byrd was previously a manned station, that was abandoned and replaced by an automatic (biased) station.
Anyone with a lick of sense would know that when you have a massive heat source lying beneath part of a massive ice sheet, that part is going to be warmer. Once these facts became known, this was obvious to anyone who has a basic grasp of reality. That might be proven to be false by scientific testing at some point, but IMO it’s the ultimate in stupidity to not begin from what we know (make an assumption), and then try to disprove it, rather than assuming we can’t know anything until we do a study.
Has anyone bothered to make a comprehensive survey of offshore water temps surrounding Antarctica?
In the figure from Bingham et al.; is New Zealand being used as a scale or is has it slide further south in the last year or so? Perhaps a map projection issue? Looks wrong
The bottom line is this raises more questions about what is claimed to be “settled” science, as the above debate simply confirms. Combine the facts that much of the world is covered in water and that we understand more about the moon than the oceans and I can’t see how any scientist can claim things are “settled” at all. We’re now in a ridiculous situation where any new data, such as this, is being forced to fit with what climate ‘scientists’ want people to believe.
Any claim to proper scientific method went out of the window a long time ago where climate science is concerned. Stuff such as this just confirms it.
Real science! Real observations! Who would have thought?
Interesting, but these geothermal hot spots have nothing to do with Antarctic air temps 3-4km of ice above them. Steig was just wrong, it’s entirely coincidental.
Heat doesn’t rise?
Maybe not. The net heat-flow is nearly always upwards through an icecap so a slightly warmer bottom will possibly result in a very slightly warmer surface as well, though the effect will certainly be very small. Though more likely the additional heat will go into melting ice and a larger subglacial water flow.
My thoughts also.
Melting ice should warm the sea leading to volcanic heat rising to the surface warming the atmosphere.
The mechanism would be convective, not conductive through the insulator, ice.
“but these geothermal hot spots have nothing to do with Antarctic air temps 3-4km of ice above them. ”
Don’t let the red crayon fool you…..it’s still freezing
There isn’t 3-4 km of ice over those hotspots. Avg ice depth in western Antarctica is only about 1 km. 3-4 km ice depth is in the eastern part. The hottest of those hot spots is where the glaciers are melting.
” … and is currently losing ice, which contributes to rising sea levels.”
Seems like the requisite homage to CAGW so they could get funding.
But like so much of the BS, it’s completely wrong. The only ice that Antarctica is loosing is calving glaciers which are already floating on the oceans and will not change sea levels. Anyone who thinks that an ice sheet cantilevered miles and miles from the edge of the continent is not floating isn’t really thinking.
” The only ice that Antarctica is loosing is calving glaciers”
And what was formerly floating in the Weddell polyna, but has now melted to liquid.
As a matter of fact only calving shelf-ice was floating. Many grounded glaciers also calve into the ocean.
looks like the ground is warming causing ice to melt not cars driving down the freeway.
It looks like a red state – blue state map issue by dolt journalists. Or maybe all the Antarctic coal plants are on one side of the continent.
No, but East Antarctica and West Antarctica are very different geologically. East Antarctica is an old Precambrian shield with minimal volcanic activity, very similar to Australia (which was originally part of East Antarctica).
West Antarctica is much younger, and is tectonically quite active with a very large rift valley and lots of flanking volcanos. The Red Sea area and the East African rift is probably the best analog.
I hate the word “robust”
What sort of positional control was used for the older aeromag data? And overall what do the areomag flight tracks look like? Maybe a little positional slop built into the rest of this ‘paper’?
To quote Click and Clack “Doesn’t anyone ever screen these calls?”
“currently losing ice, which contributes to rising sea levels.”
Latest NASA study says Antarctica has been gaining ice for years.
Losing Ice On land might cause land areas to rise giving appearance of sea level going down . Melting or increasing sea ice should have zero effect on sea level. simple physics . Just need an ice cube and glass of water to prove. What am I missing?
what you’re missing is that
sea level rise from melting
land rise is almost always
greater than any rebound
of the land.
I think you have a English comprehension problem. Seems to be a problem in the MSM.
“Latest NASA study says Antarctica has been gaining ice for years.”
cite?
Why do you keep asking for studies which are common knowledge to those who follow “climate change” news?
https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-antarctic-ice-sheet-greater-than-losses
The East Antarctic Ice Sheet is the repository of most of the fresh water on earth. The West Antarctic Ice Sheet isn’t a pimple on its posterior, and if it is losing mass, it’s only because of volcanism, not CO2. If it were CO2, then the gigantic EAIS would be wasting away as well.
this link was’nt ment obiously:
https://phys.org/news/2017-05-growth-east-antarctic-ice-sheet.html