First studies of mesosphere and lower thermosphere dynamics using a
multistatic specular meteor radar network over southern Patagonia
Abstract
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. 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.