tinyurl.com/4cs4fq -> wattsupwiththat.com/2008/10/03/winds-are-dominant-cause-of-greenland-and-west-antarctic-ice-sheet-losses/
Winds are Dominant Cause of Greenland and West Antarctic Ice Sheet Losses 3 10 2008 Above image is not part of original papers, but included to demonstrate teh issue. Animation of Arctic sea-ice being pushed by wind patterns Above image is not part of original papers, but included to demonstrate the issue. Animation of Arctic sea-ice being pushed by wind patterns. Note that the animation is large, about 7 MB and may take awhile to load on your computer.
Here we present hydrographic data that show a sudden increase in subsurface ocean temperature in 1997 along the entire west coast of Greenland, suggesting that the changes in Jakobshavn Isbr were instead triggered by the arrival of relatively warm water originating from the Irminger Sea near Iceland. We trace these oceanic changes back to changes in the atmospheric circulation in the North Atlantic region. We conclude that the prediction of future rapid dynamic responses of other outlet glaciers to climate change will require an improved understanding of the effect of changes in regional ocean and atmosphere circulation on the delivery of warm subsurface waters to the periphery of the ice sheets.
Modelling Circumpolar Deep Water intrusions on the Amundsen Sea continental shelf, Antarctica' by Thoma et al, published in GRL. The Abstract states: Results are presented from an isopycnic coordinate model of ocean circulation in the Amundsen Sea, focusing on the delivery of Circumpolar Deep Water (CDW) to the inner continental shelf around Pine Island Bay. The warmest waters to reach this region are channeled through a submarine trough, accessed via bathymetric irregularities along the shelf break. Temporal variability in the influx of CDW is related to regional wind forcing. Easterly winds over the shelf edge change to westerlies when the Amundsen Sea Low migrates west and south in winter/spring. This drives seasonal on-shelf flow, while inter-annual changes in the wind forcing lead to inflow variability on a decadal timescale. A modelled period of warming following low CDW influx in the late 1980's and early 1990's coincides with a period of observed thinning and acceleration of Pine Island Glacier.
sea ice 22 responses to "Winds are Dominant Cause of Greenland and West Antarctic Ice Sheet Losses" 3 10 2008 Leon Brozyna (15:42:41) : What are they doing here, actually trying to do a scientific study? They must be in the pay of big oil or big coal or big whatever. From Koberle et al: These results make connecting "global warming" to Arctic ice thinning very difficult for two reasons. First, large decadal and longer-term variability masks any trend. Second, the wind stress strongly effects the long-term development of ice volume. A long-term change in wind stress over the Arctic, possibly by an increase in the number of atmospheric circulation states that favor ice export, would effect the ice volume in a similar manner as a temperature increase. Mechanisms determining the variability of Arctic sea ice conditions and export. Two other papers: Rigor et al suggests that Arctic warming is not melting the ice, but thinner ice is warming the arctic. ice pack is thickening in some places, thinning in others, due to AO. that is, that the thinning ice has warmed SAT by increasing the heat flux from the ocean. Holloway et al suggests that shifting winds are responsible for ice thickness change.
Colin Aldridge (16:14:18) : I wonder if this change in glacier melt is caused by the AMO ( atlantic multidecadal oscillation ) which was warming during the 90's and is incidently now entering a cool phase. The AMO correlates well with global temperature variation over the past 100 years, not as well as CO2 but the two together give a pretty good fit.
Colin Aldridge (16:28:18) : The papers, now I read the full text does suggest AMO as the cause for the the Arctic and ENSO and SAO for Antarctica. Supposedly clouds covered the area so no one know if the area was open sea or warmer ice, or what. Andy Revkin knows someone who can get the photos, and I'd like some meteorologists to look at the clouds to see if they are normal Arctic clouds or the sort of clouds that would appear over open water or warmer ice. I don't think anyone knows for sure what effect the volcano of 1999 had. I submit that you can see its effect, first with the great blue spot suddenly appearing, surrounded by thicker stuff, then the dissolution of the spot as it moves south, finally flushed out in 2001 and carrying some old ice with it. the spot is right over the ridge, in the approximate area of the volcano. These authors suggest that all temperature anomalies of the 20th century can be explained by major cycles and their interactions.
it is approximately over the volcano on the Gakkel Ridge which erupted in 1999. Smurfit School of Business and the Management Institute of Paris" Have a Smurferiffic day!
I predict that in a few months we'll never even be able to see the little stumble. After all, the new carbon economy will require a very stable and trustworthy data set. You've probably heard of him but if not I thought these links may be of interest to your readers. I personally studied his stuff and found him to be accurate to what he says which took some time to glean from the forecast indexes.
As predicted by the astronomers, the North Pole has gone into 24 hours of darkness (as opposed to the warmers who have no idea this kind of thing can actually happen) for the next six months as has happened every year for the last 45 billion years and it will continue to get colder until the North pole reaches its normal middle of winter -40C to -60C. or the moon's gravity, can load up a bay with water then instead of the water relaxing back from whence it came learn it may escape down a trough to emerge at a far distance to effect a change in weather.
png I wonder if anyone would publicize a record increase, if it so happens. They found that the summer melting period for 2008 was unusual in that more first-year ice survived at the end of the 2008 summer compared to 2007. This was due to a combination of factors, such as the more northerly latitudes where the first-year ice was found, the warmer temperatures, and winds that had not compacted the ice as they had done in 2007. As a result, 2008 came second to 2007 in terms of record melting of sea ice - and the North Pole remained iced up."
|
http://csua.com/feed/