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

Abstract

The mesosphere and lower thermosphere (MLT) is the atmospheric region that couples the lower and upper parts of the terrestrial atmosphere. For this reason, knowledge of its dynamics is of great importance in order to understand the behavior of the atmosphere as a whole. The coupling is accomplished mainly via propagation of three dominant types of waves: planetary waves (PWs), tides, and gravity waves (GWs). PWs are waves with scales of thousands of kilometers and periods of up to ∼30 days. They are mainly generated in the troposphere by land-sea discontinuities, or triggered in situ by, for example, baroclinic instabilities and filtered GWs (e.g., H. L. Liu & Roble, 2002;McCormack et al., 2014;Rossby, 1939). Tides are also waves with horizontal scales of thousands of kilometers, but periods that are subharmonics of the solar and lunar days. Thermal tides are mainly a consequence of solar radiation absorption by water vapor in the troposphere and ozone in the stratosphere, while the lunar tide results from the gravitational pull of the Moon (e.g., Forbes, 1984;Lindzen & Chapman, 1969). GWs are small to medium scale waves with periods ranging from about 5 min to many hours. They can be triggered by a myriad of different sources, e.g., the orography, thunderstorms, shear instabilities, convection, etc.

Study of second-order wind statistics in the mesosphere and lower thermosphere region from multistatic specular meteor radar observations during the SIMONe 2018 campaign

“…Although we operated the systems for nearly 10 days, in this work we focused only on seven days, when the majority of links were operational. Given the success of the campaign, operational versions using the SIMONe approach were installed in central Peru and southern Argentina in September 2019 (Chau et al, 2020;Conte et al, 2020).…”