Thursday, March 19, 2015

Re: [Geology2] East Antarctica melting could be explained by oceanic gateways



What is significant on this story was that the IPCC harrumphed  with no uncertainty that they had identified EVERY and ALL possible climate drivers so anything left over must be human caused.  Every week we have several non-human-related climate-drivers are published. The western-zone glacier melt was said to be human caused for years by the IPCC but they failed to identify the nearly dozen or so active subterranean  volcanoes under the shelf nor the 60± year cycle of warm southern Pacific (easterly) wind oscillation which is still moving easterly about to start its swing back westerly.

I recently reviewed a report which said all 180(?) models of climate change "worked" when historical data was run through them 1000's of times.  What they did not mention was their variability was so wide as the margin of error was always outside the prediction zone, such that  high temperatures could also just as well be trending low temperatures in 50-100 years of the timeframe used--Ergo no predictive value-- a coin toss. The normal margin of error( moe) in the calculated average, was larger than the possible range of temperatures that the model said would exist. " We predict that they temperature could rise 3-5° but it could just as well go up 6 or down 8 according to our model". Anytime your margin of error exceeds you prediction then your prediction is worse than a coin toss.  That said...

They also didn't address that most(?) of the models at least the IPCC models, tested by some other researchers, showed higher global temperatures regardless of whether the values used were all "high" or all  "low" or anywhere  between-- he got the same results as the historical data "aka model validation runs)--again in statistics-- no predictive value. In reality, the models were tweaked until they matched the IPCCs three models success was claimed and more research money was to be had.  Wannabee models that didn't fit the "message" didn't get funded. 

Models/Simulations and statistical processing for reliability:
Statistically, a researcher repeats the runs with fixed input values (e.g. yearly temperatures) to check for intra-model run-to-run consistency / then add a variables such as carbon dioxide levels to check for sensitivity.  They do this 1000s of times to find a consistency which they can analyze with different statistical treatments ( modes, means, averages,  standard deviations, etc.).  Bottom line is that none of the 180(?) including the 3 (?) used by the IPCC public domain models, had remotely narrow outcomes(e.g. high-sloped bell curves: a narrow spread of std.dev.), indicating that the models are not even consistent with themselves.

 Are there no intellectually honest researchers which will let the science fall where it may and give us the data and statistical treatments and see if they data can be replicated by other scientist on both sides of the debate?  And how would we know if we found them?
Eman


From: "Lin Kerns linkerns@gmail.com [geology2]" <geology2@yahoogroups.com>
To: Geology2 <geology2@yahoogroups.com>
Sent: Tuesday, March 17, 2015 9:39 PM
Subject: [Geology2] East Antarctica melting could be explained by oceanic gateways

 

East Antarctica melting could be explained by oceanic gateways

Date:
March 16, 2015
Source:
University of Texas at Austin
Summary:
Researchers have discovered two seafloor gateways that could allow warm ocean water to reach the base of Totten Glacier, East Antarctica's largest and most rapidly thinning glacier. The discovery probably explains the glacier's extreme thinning and raises concerns about how it will affect sea level rise.











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The Totten Glacier catchment (blue outline) is a collection basin for ice and snow that flows through the glacier. It's estimated to contain enough material to raise sea levels by at least 11 feet.
Credit: Australian Antarctic Division


Researchers at The University of Texas at Austin's Institute for Geophysics (UTIG) in the Jackson School of Geosciences have discovered two seafloor gateways that could allow warm ocean water to reach the base of Totten Glacier, East Antarctica's largest and most rapidly thinning glacier. The discovery, reported in the March 16 edition of the journal Nature Geoscience, probably explains the glacier's extreme thinning and raises concerns about how it will affect sea level rise.
Totten Glacier is East Antarctica's largest outlet of ice to the ocean and has been thinning rapidly for many years. Although deep, warm water has been observed seaward of the glacier, until now there was no evidence that it could compromise coastal ice. The result is of global importance because the ice flowing through Totten Glacier alone is sufficient to raise global sea level by at least 11 feet, equivalent to the contribution of the West Antarctic Ice Sheet if it were to completely collapse.
"We now know there are avenues for the warmest waters in East Antarctica to access the most sensitive areas of Totten Glacier," said lead author Jamin Greenbaum, a UTIG Ph.D. candidate.
The ice loss to the ocean may soon be irreversible unless atmospheric and oceanic conditions change so that snowfall outpaces coastal melting. The potential for irreversible ice loss is due to the broadly deepening shape of Totten Glacier's catchment, the large collection of ice and snow that flows from a deep interior basin to the coastline.
"The catchment of Totten Glacier is covered by nearly 2½ miles of ice, filling a sub-ice basin reaching depths of at least one mile below sea level," said UTIG researcher Donald Blankenship.
Greenbaum and Blankenship collaborated with an international team from the United States, Australia, the United Kingdom and France.
Because much of the California-sized interior basin lies below sea level, its overlying thicker ice is susceptible to rapid loss if warm ocean currents sufficiently thin coastal ice. Given that previous work has shown that the basin has drained its ice to the ocean and filled again many times in the past, this study uncovers a means for how that process may be starting again.
"We've basically shown that the submarine basins of East Antarctica have similar configurations and coastal vulnerabilities to the submarine basins of West Antarctica that we're so worried about, and that warm ocean water, which is having a huge impact in West Antarctica, is affecting East Antarctica, as well," Blankenship said.
The deeper of the two gateways identified in the study is a three-mile-wide seafloor valley extending from the ocean to beneath Totten Glacier in an area not previously known to be floating. Identifying the valley was unexpected because satellite analyses conducted by other teams had indicated the ice above it was resting on solid ground. Special analysis of ice-penetrating radar data shows the bottom of the ice over the valley is smoother and brighter than elsewhere in the area -- tell-tale signs that the ice is floating and being eroded by the ocean.
"Now we know the ocean is melting ice in an area of the glacier that we thought was totally cut off before," Greenbaum said. "Knowing this will improve predictions of ice melt and the timing of future glacier retreat."
In some areas of the ocean surrounding Antarctica, warm water can be found below cooler water if it is saltier and, therefore, heavier than the shallower water. As a result, seafloor valleys that connect this deep, warm water to the coast can especially compromise glaciers, a process previously known to be occurring along the coast of the West Antarctic Ice Sheet. Although glaciers in West Antarctica have received more attention in previous Antarctic studies, this work shows that similar processes are underway in East Antarctica where there is also the possibility for retreat into an interior basin. As in the West Antarctic Ice Sheet, complete collapse of the Totten Glacier catchment may take many centuries, although the timing of retreat in both places is the subject of intensive research.
The UTIG team collected the data during five Antarctic field campaigns using aircraft loaded with equipment to analyze the ice and seafloor in regions that even icebreakers are unable to reach. The airplane was outfitted with radar that can measure ice several miles thick, lasers to measure the shape and elevation of the ice surface, and equipment that senses the Earth's gravity and magnetic field strengths, which are used to infer seafloor shape.
The data for this study were gathered as part of the UTIG-led ICECAP (International Collaboration for Exploration of the Cryosphere through Aerogeophysical Profiling) project with support from the U.K.'s Natural Environment Research Council, the U.S. National Science Foundation, the Australian Antarctic Division, as well as NASA's Operation IceBridge, the G. Unger Vetlesen Foundation, and the University of Texas at Austin's Jackson School of Geosciences. The ICECAP aircraft was operated under contract to the University of Texas Institute for Geophysics by Kenn Borek Air LTD., Calgary, Alberta, Canada.

Story Source:
The above story is based on materials provided by University of Texas at Austin. Note: Materials may be edited for content and length.

Journal Reference:
  1. J. S. Greenbaum, D. D. Blankenship, D. A. Young, T. G. Richter, J. L. Roberts, A. R. A. Aitken, B. Legresy, D. M. Schroeder, R. C. Warner, T. D. van Ommen, M. J. Siegert. Ocean access to a cavity beneath Totten Glacier in East Antarctica. Nature Geoscience, 2015; DOI: 10.1038/ngeo2388

Cite This Page:
University of Texas at Austin. "East Antarctica melting could be explained by oceanic gateways." ScienceDaily. ScienceDaily, 16 March 2015. <www.sciencedaily.com/releases/2015/03/150316183935.htm>.

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