Upper atmosphere semidiurnal tides at Christchurch (44°S) and Scott Base (78°S)

Lunar and solar semidiurnal tides have been determined from winds measurements in the 82 to 100 km height range at Christchurch and Scott Base made during 1983–1984. At Christchurch, the solar tide has maximum amplitudes in April and December, while at Scott Base, only the December maximum is present at all heights. Phases at Scott base mostly agree with those measured earlier at Mawson, but vertical wavelengths are always long. The lunar tide was difficult to isolate at Christchurch, but the winter to summer phase reversal was clear. This was also seen at Scott Base.