Climate of extremes - Antarctica: Global Science from a Frozen Continent - page 102

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Climate of extremes

JOHN J. CASSANO

We had discovered an accursed country. We had found the
home of the blizzard.
Sir Douglas Mawson, Australasian Antarctic Expedition, 1911 - 14

Antarctica is the coldest, windiest and driest continent on Earth. Temperatures
at the surface of the continent have fallen to 89ºC, the coldest surface temperature

ever observed on Earth, and monthly mean wind speeds have been recorded in
excess of hurricane strength. Antarctica can be considered a desert, yet 99% of the
continent is covered in ice. What is it about the Antarctic continent that causes such
extreme weather and how does Antarctic weather affect the rest of the planet?
Scientists have been fascinated by Antarctica

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s weather since the earliest
explorers returned with unbelievable descriptions of storms, cold and wind. We
now know much more about the processes that create this unique, harsh and
dramatic climate and how this distant polar climate impacts those of us who live
in more hospitable locations. While it may be dif

cult to see how Antarctica, a
continent at the bottom of our planet and far distant from where most of us live,
can impact our lives, Antarctica plays a central role in shaping and driving our
global climate and the changes that occur there can have far reaching impacts on
the rest of the planet.

The Earth ' s radiation budget

At the simplest level the climate and weather of Earth is driven by an imbalance in
the amount of energy gained in the tropics and the amount of energy lost at the
poles. We need to know where this energy comes from and why there is an