Longitudinally Varying Thermospheric Composition and Its Connection to the Extraordinary 2019 SSW

Abstract:

We are in an era of unprecedented opportunities for using cross-platform observations to elucidate the complex dynamics of the thermosphere and ionosphere. TIMED/GUVI observations of O/N2 suggest that there is a persistent longitudinal variability during quiet periods. However, because of the observational geometry of the LEO based TIMED satellite, it is difficult to impossible to separate temporal and spatial variability. By combining TIMED/GUVI observations with GOLD observations, we can conclusively show that there is, in fact, a very distinct longitudinal variability in O/N2. O/N2 is generally higher over the South American sector than it is over the Eastern Atlantic sector during geomagnetically and geophysically quiet conditions. This longitudinal variability persisted during geophysical events, including the extraordinary minor Sudden Stratospheric Warming of 2019 that occurred in the Antarctic. Here we will show results from both TIMED/GUVI and GOLD observations of O/N2 that shows this remarkable longitudinal variability and its connection to the ionosphere through TEC measurements.