Deep, old water explains why Antarctic Ocean hasn’t warmed
https://www.washington.edu/news/2016/05/30/deep-old-water-explains-why-antarctic-ocean-hasnt-warmed/[font face=Serif]May 30, 2016
[font size=5]Deep, old water explains why Antarctic Ocean hasnt warmed[/font]
Hannah Hickey
[font size=3]The waters surrounding Antarctica may be one of the last places to experience human-driven climate change. New research from the University of Washington and the Massachusetts Institute of Technology finds that ocean currents explain why the seawater has stayed at roughly the same temperature while most of the rest of the planet has warmed.
The study resolves a scientific conundrum, and an inconsistent pattern of warming often seized on by climate deniers. Observations and climate models show that the unique currents around Antarctica continually pull deep, centuries-old water up to the surface seawater that last touched Earths atmosphere before the machine age, and has never experienced fossil fuel-related climate change. The paper is published May 30 in
Nature Geoscience.
With rising carbon dioxide you would expect more warming at both poles, but we only see it at one of the poles, so something else must be going on, said lead author Kyle Armour, a UW assistant professor of oceanography and of atmospheric sciences. We show that its for really simple reasons, and ocean currents are the hero here.
[font size=1]Observed warming over the past 50 years (in degrees Celsius per decade) shows rapid warming in the Arctic, while the Southern Ocean around Antarctica has warmed little, if at all.Kyle Armour/University of Washington
Kyle Armour/University of Washington[/font]
Gale-force westerly winds that constantly whip around Antarctica act to push surface water north, continually drawing up water from below. The Southern Oceans water comes from such great depths, and from sources that are so distant, that it will take centuries before the water reaching the surface has experienced modern global warming.
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