On the Extraordinary Katabatic Winds of Adelie Land
Gerd Wendler1, Charles Stearns2, George Weidner2, Guillaume Dargaud3, and Thomas Parish4
(1) Geophysical Institute, University of Alaska Fairbanks, Fairbanks, Alaska 99775
(2) Dept. of Atmospheric and Oceanic Sciences, University of Wisconsin, Madison, WI 53706
(3) Centre National de Recherches Meteorologiques, Toulouse, France
(4) Dept. of Atmospheric Science, University of Wyoming, Laramie, WY 82071
The winds observed in Adelie Land, Eastern Antarctica, are the strongest observed anywhere on Earth close to sea level, e.g. Cape Denison measured a mean annual wind speed of about 20 m/s. Some historical data from the area are available, however such measurements were carried out at different places for different time periods. Hence in December 1992, we placed four automatic weather stations along the coast of Adelie Land, two in the maximum wind jet (Port Martin and Cape Denison), and one on each side of this jet (D 10 close to Dumont d'Urville and Penguin Point, respectively).
We obtained about 3 months of good data, as on 25 March 1993 a strong storm destroyed 3 of the 4 wind sensors. Wind velocities are discussed as function of other meteorological parameters. Further, the interrelationship between the stations are described. Some of the findings are:
1) The very high wind speeds reported earlier this century are correct. The wind directional constancy is high.
2) Cape Denison was confirmed to be the windiest station, not only for Antarctica, but also close to sea level for planet Earth.
3) Very strong wind speeds have a more off-shore direction than weaker ones.
4) The general atmospheric pressure gradient enhanced or inhibited the gravity flow. This is especially well pronounced in summer.
In summer, above normal pressure is correlated with above normal temperatures, in fall the opposite holds true.
Funding was provided in part by a grant to the Alaska Climate Research Center by the State of Alaska.
1997, Journal of Geophysical Research, Vol 102(D4), 4463-4474.