There ’s a mad scurry underway in the scientific community to learn everything possible about theimperiled West Antarctic shabu bed sheet , whose glaciers oblige back enough water to enkindle orbicular sea level by 10 foot or more . The latest troubling climate factor to keep an eye on ? El Niño .
A team of researchershas learnedthat the powerful 1997 - 98 El Niño outcome dramatically accelerated the thaw of the deoxyephedrine shelves buttress glaciers in West Antarctica ’s Amundsen sea sector . The finding declare oneself additional insight into the dynamics of this highly study stretch of frappe .
They also raise new questions about the succeeding stability of West Antarctica ’s monumental coastal glacier , which are presently sheddingbillions of tons of iceper year . Some mood models projectmore extreme point El Niño events in the futurity , and one possibility the novel work raises is that El Niño - driven cutting of chicken feed ledge could push glacier that were already weakened by climate change into a state of unstoppable collapse .
confidential information work source Fernando Paolo , who lead the inquiry at the Scripps Institution of Oceanography and is presently based at NASA ’s Jet Propulsion Laboratory , unearth the 1997 - 98 El Niño ’s oversized wallop in West Antarctica while he was mining satellite records to look for short - condition factors that impact the growth and thinning of ice shelf .
“ [ El Niño ] occur out while we were analyzing the data to see what we could learn about variability , ” Paolo say Earther . “ So we started delve in . ”
El Niño is a repeat climate pattern defined by above - ordinary ocean temperatures in the equatorial Pacific that affect atmospheric condition patterns around the creation , run to a slight uptick in globose temperature . To cod out its impact on the West Antarctic trash piece of paper , Paolo and his colleagues looked at 23 years of planet information collected by four European Space Agency - led satellite altimeters , which measure the height of crank shelves . The phonograph recording , span 1994 to 2017 , comprehend four El Niño events , include the two strong ones on record , the 1997 - 98 and 2015 - 2016 El Niños .
After obtaining precise ice ledge height data , the researchers used a regional mood fashion model to work out how much of the variableness on a yr - to - class basis was due to snowfall ( which induce ice shelf to acquire taller ) versus sea - driven melting ( which causes ice ledge to thin out from below ) .
The findings , publish Monday in Nature Geoscience , reveal that the 1997 - 98 El Niño top to a real loss of mass from the bottom of the chalk shelves in West Antarctica ’s Amundsen sea sector , even as the shelves appeared to grow about ten column inch taller from additional snowfall . Overall , crank shelf in the Amundsen sea sector lost about five times as much stack as they gained during the event .
accord to Paolo , the changes can be explained by El Niño force a high-pitched pressure unusual person into the low - pressure system of rules park over the Amundsen ocean , impacting wind patterns and driving more snowfall in West Antarctica . This change in the windfield also touch on ocean circulation , helping to pump warm , abstruse sea currents to the aerofoil , where they ate off at the shabu from below .
The knock-down 2015 - 2016 El Niño did n’t do a similar loss of frappe , leading Paolo to suspect that multiple climate conditions need to be touch to trigger a major melt . He ’s now gathering additional satellite data to draw out the phonograph recording further back in time and judge to better understand the effect of unretentive - term climate oscillations on these ice shelves .
Alison Banwell , a glaciologist at the Scott Polar Research Institute , University of Cambridge , who was not involve with the new research tell Earther she found the subject interesting , though “ not needfully surprising . ”
“ However , I am wondering whether surface melting was accounted for , and how significantly different Earth’s surface thawing rates were during El Nino eld , compared to other days , ” Banwell recite Earther . “ As in addition to basal thawing [ melting at the bottom of the ice ledge ] , surface melting is an of import contributor to cutting pace , particularly during the summer calendar month . ”
Peter Neff , a glaciologist at the University of Washington who also was n’t involve , say the new subject field was “ impressive work ” that “ demonstrate what many have suspected for a while”—a connection between El Niño and the Amundsen sea coastline .
“ The biggest question this bring to my mind is what part the forties El Niño had on Amundsen Sea seacoast glaciers , ” Neff state Earther . “ There are several published lines of grounds suggesting [ the 1940s El Niño ] could be the initial ‘ bump ’ that started the current ice red in this region . ”
That connexion , between light term factors like El Niño and long term , prominent exfoliation change in West Antarctica is specially important if we want to prefigure how this massive ice sheet will respond to human - driven warming .
“ When we see a dramatic collapse or retreat , it was because the glacier was already in an unstable precondition , ” Paolo said . “ And if they are in that state , any perturbation can [ be the ] initiation , like a big El Niño . Obviously , this is all suppositional , but it makes perfect sentience to think that fashion . ”
El Niño alone wo n’t trigger off anice apocalypse — but when you blend it with human carbon defilement , it might just be the crack that sets off the avalanche .
Update : This article has been updated to clarify that El Niño forces a high pressure anomaly into a persistent blue imperativeness realm over the Amundsen ocean .
AntarcticaClimate changecryosphereice on fragile ice
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