The Annual Behavior of the Semidiurnal and Diurnal Pressure Variations in East Antarctica

A 15-year (1980-95) three-hourly record of surface pressure from the automatic weather station Dome Concordia (123.00„aE, 74.30„aS, 3280 m a.s.l.) in East Antarctica was analyzed to study the annual behavior of the semidiurnal and diurnal variation associated with atmospheric tides excited by heating due to insolation absorption by ozone and water vapor. The mean daily behavior of the pressure variation shows maxima around 0900 LT and 2100 LT. This variation is more intense during the austral winter. The time series of a Total Ozone Mapping Spectrometer (TOMS) were analyzed to study the correlation between the local pressure tidal oscillations and the annual behavior of total ozone over the globe. A clear correlation between the intensity of the pressure semidiurnal variation and global total ozone in both the annual and long-term trends was found. The mean annual behavior of the semidiurnal tides and global total ozone is quite similar with two maxima and one deep minimum. Maxima in semidiurnal tides occur in May and September-October, in ozone they are observed in April-May and September. A deep minimum in semidiurnal tides occurs in December-February, and a minimum of ozone is observed in December.