Juan Federico Conte

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This paper presents for the first time results on winds, tides, gradients of horizontal winds, and momentum fluxes at mesosphere and lower thermosphere (MLT) altitudes over southern Patagonia, one of the most dynamically active regions in the world. For this purpose, measurements provided by SIMONe Argentina are investigated. SIMONe Argentina is a novel multistatic specular meteor radar system that implements a SIMONe (Spread Spectrum Interferometric Multistatic meteor radar Observing Network) approach, and that has been operating since the end of September 2019. Average counts of more than 30000 meteor detections per day result in tidal estimates with statistical uncertainties of less than 1 m/s. Thanks to the multistatic configuration, horizontal and vertical gradients of the horizontal winds are obtained, as well as vertical winds free from horizontal divergence contamination. The vertical gradients of both zonal and meridional winds exhibit strong tidal signatures. A diurnal pattern can also be observed in the vertical winds during certain days. Mean momentum fluxes are estimated after removing the effects of mean winds using a four-hour, eight-kilometer window in time and altitude, respectively. Reasonable statistical uncertainties of the momentum fluxes are obtained after applying a 28-day averaging. Therefore, the momentum flux estimates presented in this paper represent monthly mean values of waves with periods of four hours or less, vertical wavelengths shorter than eight kilometers, and horizontal scales less than 400 km.