Planetary waves and intraseasonal oscillations at Davis, Antarctica, from undersampled time series

Abstract

Nine years (1997 to 2005) of nighttime hydroxyl (6‐2) band rotational temperatures were measured with a scanning spectrometer over Davis station, Antarctica (68.6°S, 78.0°E). A novel time series analysis technique is employed to create continuous long‐term time series, and local spectral analysis of these temperature time series was performed to search for planetary wave and intraseasonal oscillations. Many significant wave signatures were observed. Coincident observations are found in a comparison between these temperature wave signatures and horizontal wind measurements made from a collocated MF radar. Several very long term wave signatures (30 to 50 days) are seen in the OH temperatures which are absent from the MF radar winds. An increase in wave activity is seen in the late winter season. Interannual variations are also shown indicating a peak in 2002; the year of the Southern Hemisphere Stratospheric Warming Event.