An Observational and Multi-Model Analysis of Neutral Winds in the Low-Latitude Thermosphere

Abstract:

The dynamical behaviors of the ionized and neutral particles are primarily driven by neutral winds in the low latitudes, which in turn produce coupling and electrodynamic interactions in the upper atmosphere. Measurements and understandings of thermospheric wind dynamics can address many unanswered scientific questions regarding geospace phenomena. Currently, available ground-based observations for the continual 24‐hour thermospheric winds are sparse, though they also play a decisive role in improving, validating, and developing new/existing wind models. Most of the ground-based Fabry-Perot interferometric wind measurements are limited to nighttime and cloudless sky conditions. Recently, Second‐generation, Optimized, Fabry‐Perot Doppler Imager (SOFDI), a triple‐etalon Fabry‐Perot interferometer, is designed to measure both day and nighttime thermospheric winds from OI 630‐nm emission and is currently operating at the Huancayo Geophysical Observatory in Peru near the geomagnetic equator. Here, we present a comparative analysis of the observed SOFDI winds data and several model results, including, but not limited to, Horizontal Wind Model 2014 (HWM-14), Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics (CTIPe) model, Whole Atmosphere Model (WAM), Magnetic mEridional NeuTrAl Thermospheric (MENTAT) model, and Field Line Interhemispheric Plasma (FLIP) model. Also, the performances of these models are examined by comparing their outputs to the direct-measured thermospheric winds. Finally, we investigate and discuss the sources, drivers, and effects of the wind variability in the low-latitude thermosphere from observational and modeling perspectives.