Climate of the polar realms - The Global Climate System: Patterns, Processes, and Teleconnections - page 139

under such conditions is extremely difficult. Madigan, the meteorologist of
Mawson's expedition, wrote the following: ''For nine months of the year an
almost continuous blizzard rages, and for weeks on end one can only crawl
about outside the shelter of the hut, unable to see the arm's length owing to the
blinding drift snow. After some practice, the members of the expedition were
able to abandon crawling, and walked on their feet in these torrents of air,
'leaning in the wind'''. That such conditions are dangerous goes without
saying. A. Prudhomme, a meteorologist at Dumont d'Urville, a French station
120 km to the east of Cape Denison, never returned after a meteorological
observation, and it was assumed that he was carried by the wind out to sea.
Katabatic winds are quite shallow, having a maximum in speed a few
hundred meters above ground, and the onset and secession can be quite
abrupt. Parish ( 1982 ) was the first to model these. They can transport large
amounts of snow (Radok 1970 ), which can bury any exposed object
(Figure 5.3b ). The mass, which is transported from the continent to the
ocean, is also of importance for the mass balance in windy areas. While
extreme winds, like those reported here, occur in confluence zones, more
moderate winds are very common in Antarctica. They are indeed so common
that it can be stated that on no other continent does a single meteorological
parameter have such an influence on the surface climate of the whole con-
tinent as the katabatic wind for Antarctica.
Upper air data
More difficult to analyze than the surface data is the meteorology aloft due to
the paucity of radiosonde data. In addition, different radiosonde types are
being used, as stations of different nationalities use the radiosondes of their
home countries. Different radiosondes have different characteristics and are
not necessarily comparable. The coverage for the Peninsula and coastal areas
is representative; however, there are only two long-term inland stations.
Further, profile measurements from satellite data also have their problems
due to the strong surface inversion and the snow-covered surface. The
reanalyzed NCEP/NCAR data sets (Section 4.3 ), which have been carried
out for more than a decade, are a reliable data source.
Antarctica is surrounded by a pressure minimum, the so-called circumpolar
trough (Section 5.4 ). Cyclones are frequent (Section 5.5 ) and these areas are
well known for their fierce storms. Before the Suez and Panama Canals were
in existence, the rounding of Cape Horn and the Cape of Good Hope by
sailing ships was a dangerous and challenging affair, and a great number of
ships were lost. Over the continent, an anticyclone can be observed, the
reality of which has been debated, due to the problems of reducing data
from high altitude stations to sea level. This anticyclone is substantially
stronger in winter than in summer, but exists throughout the year. The coldest