A study of vertical evolution of Mesosphere and lower thermosphere temperature anomalies during the 2002 Southern Hemisphere Stratospheric Warming Event

Kinetic temperatures, inferred from the thermalized OH (6,2) and O2 At(0,1) rotational distribution measurements at South Pole (90o S), are presented here to investigate the effects of the 2002 Sudden Stratospheric Warming (SSW) event on the polar mesosphere and lower thermosphere region (MLT). These measurements show sudden cooling in OH temperatures and warming in O2 temperatures preceding the two minor stratospheric warming events studied here. These large temperature anomalies in the MLT temperatures preceded the breakdown in the polar vortex by about three to four weeks. These results agree with the findings of Coy et al. [2005] about the limited vertical extent of the mesospheric cooling signature, albeit the model cooling being limited to within the lower mesosphere. Planetary wave activity in the OH and O2 rotational temperature data shows intensification in the amplitudes of 5-15 day period waves during the polar vortex break down.