Characterization of the Thermospheric Mean Winds and Circulation During Solstice Using ICON/MIGHTI Observations

Using the horizontal neutral wind observations from the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument onboard NASA's Ionospheric Connection Explorer (ICON) spacecraft with continuous coverage, we determine the climatology of the mean zonal and meridional winds and the associated mean circulation at low-to middle latitudes (10 degrees S-40 degrees N) for Northern Hemisphere summer solstice conditions between 90 and 200 km altitudes, specifically on 20 June 2020 solstice as well as for a one-month period from 8 June-7 July 2020 and for Northern winter season from 16 December 2019-31 January 2020, which spans a 47-day period, providing full local time coverage.

The data are averaged within appropriate altitude, longitude, latitude, solar zenith angle, and local time bins to produce mean wind distributions. The geographical distributions and local time variations of the mean horizontal circulation are evaluated. The instantaneous horizontal winds exhibit a significant degree of spatiotemporal variability often exceeding +/- 150 m s(-1).