Climatology of short-period mesospheric gravity waves over Halley, Antarctica (76 S, 27 W)
We present a first detailed climatological study of individual quasi-monochromatic mesospheric, shortperiod
gravity-wave events observed over Antarctica. The measurements were made using an all-sky
airglow imager located at Halley Station (76S, 27W) and encompass the 2000 and 2001 austral winter
seasons. Distributions of wave parameters were found to be similar to findings at other latitudes. The
wave headings exhibited unusually strong anisotropy with a dominant preference for motion towards
the Antarctic continent and a rotation from westward during fall, to poleward in mid-winter, to
eastward in spring. This rotation was accompanied by a systematic increase of 50% in the magnitudes
of the horizontal wavelengths and observed phase speeds. It is postulated that the observed wave
anisotropy was due to a succession of wave sources of different characteristics lying equatorward of
Halley, or a dominant source mechanism evolving with time during the winter months.
Authors: Nielsen, K, Taylor, M. J., Hibbins, R. E., Jarvis, M. J.
1 January, 2009
Journal of Atmospheric and Solar-Terrestrial Physics / 71