MENTAT: A New Wind Model for Earth's Thermosphere. Issue 8 (11th August 2018) - Dandenault, P. B.
Abstract: A global database of ionosonde h m F 2 observations was used to develop a global database of equivalent neutral winds, which was then used to develop a new empirical horizontal neutral wind model called the Magnetic mEridional NeuTrAl Thermospheric model. In this paper, we (1) developed and optimized a technique for deriving magnetic meridional thermospheric neutral winds using the altitude of the peak ionosphere ( h m F 2 ) observations from bottomside ionospheric sounders, (2) validated these neutral winds with observations from Fabry‐Pérot interferometers (FPIs), (3) developed a new model of horizontal, magnetic meridional, equivalent neutral winds in the midlatitude regions from a global database of ionosonde observations spanning the years 1961 to 1990. Our new method for generating the winds compares well with FPI wind observations and illuminates nonphysical behavior in the horizontal thermospheric neutral wind model. Magnetic mEridional NeuTrAl Thermospheric neutral winds compare well with FPI wind observations over both short‐ and long‐time periods, and the model produces winds as a function of the year, day of year, universal time, solar flux, geographic latitude, and geographic longitude. Two major findings are (1) a distinct solar cycle wind variation that was not captured in other empirical models using other data sets and (2) global measurements of ionospheric h m F 2, which provide constraints on the global wind field that is particularly valuable considering the persistent lack of space‐based F region winds and the inability of FPIs to operate during the day, when cloudy, or under moon‐up conditions. Plain Language Summary: A new wind model for Earth's thermosphere has been developed, the Magnetic mEridional NeuTrAl Thermospheric (MENTAT) model. The model produces horizontal winds along the local magnetic meridian as a function of the year, day of year, universal time, solar flux, geographic latitude, and geographic longitude. The winds compare well with wind observations over both short‐ and long‐time periods, and the modal has advantages over similar models. Key Points: MENTAT is a new F‐region thermospheric neutral wind model The winds include hourly, diurnal, seasonal, and decadal variability The model includes solar flux (F10.7A) dependence