Stratospheric warming effects on thermospheric O(1S) dayglow dynamics

This study examines the effect of a sudden stratospheric warming (SSW) on the thermosphere, and in particular the response of thermospheric O(S-1) dayglow as a proxy for SSW-induced variations in the atomic oxygen volume mixing ratio. Thermospheric O(S-1) volume emission rates and temperatures observed by the WIND Imaging Interferometer on UARS in February 1993 at latitudes from 50 degrees N to 70 degrees N and from 90 km to 280 km height have shown a depletion above 140 km in the daytime O(S-1) volume emission rates, which commenced around the onset of the SSW and lasted over a period of 3-4 days before returning to and exceeding the pre-SSW values during the SSW recovery phase. Below 140 km height the effect was manifested by a fourfold enhancement in the O(S-1) volume emission rate at similar to 100 km, which correlated with the cold temperature anomaly of the SSW at and below the stratopause.