Climate, weather and tides at Mawson

Moon shining on East Bay
A beautiful evening with full moon over East Bay (Photo D McVeigh)

Mawson’s climate is typical of much of the coast of East Antarctica where the ice cap falls steeply to sea level.  The main feature is the 'katabatic', or gravity wind which results from the 'drainage' of cold air down the steep slopes of the ice sheet from the high interior of the continent. 

Winds are predominantly from the east and south, the mean annual speed being 21 knots (almost 40 km/h.). Not infrequently prolonged periods of strong wind occur averaging over 50 knots, with maximum gusts during these times often exceeding 130-140 knots. Mean wind speed decreases seaward with distance from the icecap as the cold air loses its speed across the fast ice or sea off-shore.

As it lies south of the Antarctic Circle, the sun does not rise at Mawson for approximately six weeks from the first week in June and does not set for the same period from early December. During those six weeks in June and July, the day consists of a few hours of twilight.

Tidal predictions 

Tides are measured for many different research and operational purposes. Such measurements have a practical value in determining sea level for mapping elevations and ocean depths, tidal predictions for shipping, and in the calibration of satellite altimeters.

Tide measurements also have a research value. Sea level data helps us understand long-term climate change as well as continental readjustment, heat transfer across the continental shelf, and other oceanographic phenomena including observation of Southern Ocean oscillation.