Seasonal variability of horizontal neutral wind in the Baikal Region from Fabry—Perot interferometer observations and different versions of HWM

This study is based on observations of the atomic oxygen airglow emission at 630 nm obtained with a Fabry—Perot interferometer (FPI) of the National Heliogeophysical Complex. FPI is installed in the Geophysical Observatory of the Institute of Solar-Terrestrial Physics SB RAS (Tory, 52° N, 103° E). Doppler shifts of the emission line were measured and then converted into horizontal wind velocities along the zonal and meridional directions during nighttime and twilight periods. We analyze the seasonal variability of neutral wind components during 2022, using both FPI measurements and model calculations from three versions of the Horizontal Wind Model: HWM93, HWM07, and HWM14. The analysis covers local nighttime hours (10–24 UTC). The data was separated by seasons relative to solstices and equinoxes and filtered by cloud conditions. The discrepancies between modeled and observed wind components vary with both local time and season. None of the HWM versions provide acceptable agreement with the measurements, indicating that HWM outputs for the Baikal region should not be considered accurate. The results of this study can be used to develop recommendations for improving or adjusting HWM in order to better describe the dynamics of the upper atmosphere in the region. These findings are also useful when choosing the most suitable HWM version for estimating a specific wind component in a given season.