Monthly climatologies of zonal-mean and tidal winds in the thermosphere
as observed by ICON/MIGHTI during April 2020-March 2022
Abstract
Version 5 (v05) of the thermospheric wind data from the Michelson
Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI)
instrument on the Ionospheric CONnections (ICON) mission has been
recently released, which largely avoids local-time dependent artificial
baseline drifts that are found in previous versions of the ICON/MIGHTI
wind data. This paper describes monthly climatologies of zonal-mean
winds and tides based on the v05 ICON/MIGHTI data under geomagnetically
quiet conditions (Hp30 < 3o) during April 2020-March 2022.
Green-line winds in the lower thermosphere (90-110 km) and red-line
winds in the middle thermosphere (200-300 km) are analyzed, as these
data cover both daytime and nighttime. The altitude and latitude
structures of zonal-mean winds and tides are presented for each month,
and the results are compared with the widely-used empirical model,
Horizontal Wind Model 2014 (HWM14). The v05 wind retrieval algorithm
does not involve HWM14. The ICON/MIGHTI and HWM14 results are in general
agreement, providing a validation of the v05 ICON/MIGHTI data. The
agreement is especially good for the zonal-mean winds. The tidal
amplitudes in HWM14 are often too small compared with those from
ICON/MIGHTI as well as previous studies. A more accurate description of
tides in the thermosphere is key to the future improvement of HWM.