Observational Study of Medium-Scale Atmospheric Disturbances During Sudden Stratosphere Warming Over Alaska

The polar vortex at high latitudes extending from the upper troposphere and into the stratosphere are known to have an effect on the thermospheric and ionospheric heights even at middle and low latitudes. Scanning Doppler Imagers (SDI) at Poker Flat and Toolik Lake measure oxygen 630 nm red emission lines over Alaska region which provides zonal and meridional wind map at 250 km altitude over 60-80 N and 130-165 W during the nighttime. We study day-to-day medium-scale atmospheric disturbances (MSTADs) in the thermosphere winds owing to gravity-wave perturbations especially during sudden stratosphere warming (SSW) event. The goal is to highlight the importance of stratosphere-ionosphere coupling at high latitudes due to modified gravity-wave activity in lower atmospheric regions during SSW event.