Summary
A new all-sky imaging Fabry-Perot spectrometer has been installed at Mawson station (67°36' S, 62°52' E), Antarctica. This instrument is capable of recording independent spectra from many tens of locations across the sky simultaneously. Useful operation began in March 2007, with spectra recorded on a total of 186 subsequent nights. Initial analysis has focused on the large-scale daily and climatalogical behavior of winds and temperatures derived from observations of the 630.0 nm airglow line of atomic oxygen, originating from a broad layer centered around 240 km altitude, in the ionospheric F-region. The 1993 Horizontal Wind Model (HWM93) and NRLMSISE-00 atmospheric model were used for comparison. During geomagnetically quiet periods observed winds and temperatures were generally well described by the model, although observed temperatures were consistently higher than NRLMSISE-00 predicted, by up to 100 K. During periods of heightened activity both winds and temperatures show much greater variability over relatively short time-scales. Active-period winds are poorly described by HWM93, although observed mean temperatures are in closer agreement with NRLMSISE-00 during such periods. Climatalogical behavior was found to be generally consistent with previous studies of thermospheric winds above Mawson. The collected data set is representative of quiet geomagnetic and solar conditions. Eastward winds in the afternoon generally continued until around 22 UT, when winds turned equatorward. Meridional winds in the early afternoon were much weaker http://www.agu.org/cgi-bin/SFgate/SFgate?&listenv=t...ais%2Findexes%2Fwp08%2Fwp08&maxhits=200&="SP31A-02" (1 of 2)14/05/2009 4:24:28 PM "SP31A-02" in wp08 than expected from HWM93, as was the transition to equatorward flow around midnight. There was also a negligible zonal component to the postmidnight wind whereas HWM93 predicted strong westward flow. Average temperatures between 15 and 25 UT were around 100 K higher than predicted by NRLMSISE-00.