Climatology of the Thermospheric Neutral Wind over Arecibo Observatory based on over three decades of Fabry Perot observations and an Associated Empirical Model

We present an empirical model of the thermospheric neutral wind (TNW) meridional and zonal components based on 630.0 nm nightglow Fabry-Perot Interferometer data over the Arecibo Observatory. We show and discuss the solar and geomagnetic dependencies of the TNW components and their variation over local time and season. A main result of this study is the detection of a substantial seasonal and local time dependence of the response of the TNW to solar and geomagnetic activity. In addition, we show that there is a long-term trend in the thermospheric neutral wind, which can be of a larger magnitude than the variation found in the seasonal, solar cycle and geomagnetic activity. A major signature of this trend over the last 30 years was an increase in the meridional northward component up to 1.4 m/s per year before midnight local time during the summer.