Antarctic peninsula likely to warm over next two decades
Precipitation increases also likely, study shows

Date:
March 15, 2021
Source:
Ohio State University
Summary:
An analysis of historic and projected simulations from 19
global climate models shows that, because of climate change,
the temperature in the Antarctic peninsula -- long a canary in
the coal mine for the rest of the continent -- will increase by
0.5 to 1.5 degrees Celsius by 2044.



FULL STORY ==========================================================================
An analysis of historic and projected simulations from 19 global climate
models shows that, because of climate change, the temperature in the
Antarctic peninsula will increase by 0.5 to 1.5 degrees Celsius by 2044.


==========================================================================
The projections also showed that precipitation -- a threat to ice if it manifests as rain -- will likely increase on the peninsula by about 5%
to 10% over that same time period.

The estimates were published recently in the journal Climate Dynamics.

"We are concerned about these findings. We've been seeing overall quite
big changes on the peninsula, generally getting warmer and ice shelves
and glaciers discharging into the ocean," said David Bromwich, a leading
author of the study and a research professor at The Ohio State University
Byrd Polar and Climate Research Center and department of geography.

The peninsula sticks up like a tail off the northwest side of Antarctica, curving near the southernmost part of South America and Chile.

Since the 1950s, the peninsula, along with the rest of the western part
of Antarctica, has been one of the fastest-warming regions on Earth. And because it is covered in mountains -- the highest peak is just over
10,600 feet - - standard climate models overlook some of the nuances of
how climate change affects the peninsula, Bromwich said.



==========================================================================
"The issue for the Antarctic peninsula is that it's this narrow but high mountain range, and these big models spanning the whole continent don't
take that into account. Our goal was to provide more detail in those projections," he said.

The analysis found that the greatest increases in temperature -- about 2 degrees Celsius -- were likely to happen in the Antarctic fall and winter,
but warmer temperatures projected for summer would cause the most trouble.

That could create a double threat to the ice on the peninsula, Bromwich
said: Warmer temperatures also mean that some precipitation that might
have previously fallen as snow will likely fall as rain.

More rain means less snow on top of the ice, which protects ice from
the sun's rays by reflecting them back into the sky.

"But now, if you have bare ice, or ice that's a little bit melting,
and the sun beats down on it, a good fraction of that energy goes into melting," Bromwich said. "And we've seen this in the past with other ice shelves -- it's like a hammer, it just shatters." The study's authors
also found that, to truly predict what might happen on the peninsula,
better, more nuanced climate models are needed.

Big climate models -- those that cover the surface of the Earth --
often do not consider other factors specific to smaller regions. In
the Antarctic peninsula, Bromwich said, an overlooked factor is the modification of the westerlies, winds that blow from west to east near
either pole. The westerlies blow directly over the Antarctic peninsula, creating a sort of micro-climate that big climate models often miss.

Those nuances are especially important in the Antarctic peninsula, which
has since the late 1970s been considered an important vanguard of what
might happen throughout the rest of Antarctica. The peninsula, climate scientists have come to understand, is more susceptible to the effects
of climate change. The first person to predict that changes throughout Antarctica would first be seen on the peninsula was another Ohio State researcher, John Mercer, who was known around the world for his work on
climate change in Antarctica.

========================================================================== Story Source: Materials provided by Ohio_State_University. Original
written by Laura Arenschield. Note: Content may be edited for style
and length.


========================================================================== Journal Reference:
1. Deniz Bozkurt, David H. Bromwich, Jorge Carrasco, Roberto
Rondanelli.

Temperature and precipitation projections for the Antarctic
Peninsula over the next two decades: contrasting global and
regional climate model simulations. Climate Dynamics, 2021; DOI:
10.1007/s00382-021-05667-2 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2021/03/210315110229.htm

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