Climate of extremes - Antarctica: Global Science from a Frozen Continent - page 128

than the spacing of the points in the model, limiting the accuracy of the weather
forecasts. Another necessary ingredient for successful weather prediction is an
accurate representation of the current atmospheric state and with the limited
atmospheric observations available in the Antarctic, this is often a problem. A

nal
issue is that since some of the Antarctic atmospheric processes represented by the
equations differ from those in mid-latitude locations these models are not ideally
suited for Antarctic weather forecasting. Over the last decade modi cations to

mid-latitude numerical weather prediction models have considerably improved
numerical weather prediction in the Antarctic.
The final ingredient for successful weather forecasting is the human forecaster.

Using all of the atmospheric observations and the forecasts from one or more
numerical weather prediction models he or she then modi es it in the light of

experience and knowledge of the local weather patterns. Since no one lives in
Antarctica permanently, the weather forecasters that work there often do not
have as much experience with the local weather as a forecaster in the mid-latitudes
who lives year-round, year after year, in the location where they are forecasting.
Fortunately, many Antarctic weather forecasters return to the Antarctic for many

field seasons, and thus do gain knowledge of the local weather and experience
in forecasting for this challenging environment.
Through the addition of new automatic weather station locations around the
continent, improved satellite coverage and data processing, and advances in
numerical weather models the accuracy of Antarctic forecasts has improved
dramatically over the last 20 years. In the early 1990s forecasting beyond 8 hours was
a problem, whereas now accurate forecasts for 3 to 5 days are commonplace. This
change has had signi cant implications for those travelling to and from Antarctica

for work or for tourism, since flights to Antarctic often take 5 to 8 hours. In the early

1990s pilots flying to Antarctic would receive weather forecasts for their arrival

that were just at the edge of what weather forecasters considered reliable. As a result the
weather upon arrival would occasionally differ, sometimes quite dramatically, from
what was forecast. Aircraft operations in the Antarctic are especially susceptible to
strong crosswinds and reduced visibility due to low clouds, fog or blowing snow. If
conditions at the Antarctic landing site are too bad the incoming aircraft is unable to
land and must return to its departure airport, a situation known as a boomerang flight.

Climate change in the Antarctic

Human induced, or anthropogenic, climate change has already had a signi cant

impact on the Antarctic through the development of the ozone hole. It is also likely
that changes in the Earth s climate due to the increase of greenhouse gases in the

atmosphere will alter the Antarctic climate over the next decades to centuries.

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