Scientists may finally have an explanation on why Antarctica just isn't warming that much.
Scientists have been mystified by a persistent coldness off Antartica that seems to defy global warming patterns — but a new study suggests a possible answer.
The chill in the ocean may be the result of cold waters rising from the deep after centuries, and it may mean that the Southern Ocean off Antarctica will be the last place on Earth to feel the impact of climate change as incredibly cold waters 5,000 meters deep replace the warmer waters up top, according to a University of Washington statement.
The study notes that warm waters in the Gulf Stream tend to cool as the flow into the North Atlantic and then sink and head south to Antarctica. This proces can take centuries to make a full transit.
Winds in the Southern Ocean blow surface waters northward and draw the frigid waters up from the bottom of the ocean, which explains why the Southern Ocean has warmed just 0.02 degree Celsius since 1950, compared to 0.08 degree worldwide.
This could potentially delay the melting of ice on Antarctica, which would greatly increase sea levels globally.
“The study resolves a scientific conundrum, and an inconsistent pattern of warming often seized on by climate deniers,” the statement reads. “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 Earth’s 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 it’s for really simple reasons, and ocean currents are the hero here.”
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