Summary
High-resolution Fabry-Perot spectrometer observations of the OH(62) Q1(1) line, l834.46 nm, were made at Mawson, 67.6ºS 62.9ºE, and Davis, 68.6ºS 78.0ºE, Antarctica, in 1997. The observing program resulted in three sets of continuous OH observations suitable for tidal analysis: July 25–31 when the Mawson FPS observed for seven days, and August 3–7 and 10–14 when the Davis FPS observed for two five day intervals. Lomb-Scargle periodograms show a definitive 12 hour periodicity in the meridional and zonal winds at both stations. The OH emission intensity has a dominant 24 hour periodicity which may be either tidal or photochemical in nature. Superposed epoch analysis is used to determine amplitude and phase of the 12- and 24-hour periodicities. At these latitudes the semi-diurnal tide is dominant with ampltiudes of 10–30 ms-1 while the diurnal tide has amplitudes of only 0–5 m s-1. Comparison is made with MF radar measurements. Simultaneous measurements from a radar at Davis compare well with FPS measurements; amplitudes and phases agree and both instruments measure a larger amplitude for the semi-diurnal tide in the last two weeks of July than in the first two weeks of August.