The MATS satellite mission – gravity wave studies by Mesospheric Airglow/Aerosol Tomography and Spectroscopy

Abstract

Abstract. Global three-dimensional data are a key to understanding gravity waves in the mesosphere and lower thermosphere. MATS (Mesospheric Airglow/Aerosol Tomography and Spectroscopy) is a new Swedish satellite mission that addresses this need. It applies space-borne limb imaging in combination with tomographic and spectroscopic analysis to obtain gravity wave data on relevant spatial scales. Primary measurement targets are O2 atmospheric band dayglow and nightglow in the near infrared, and sunlight scattered from noctilucent clouds in the ultraviolet. While tomography provides horizontally and vertically resolved data, spectroscopy allows analysis in terms of mesospheric temperature, composition, and cloud properties. Based on these dynamical tracers, MATS will produce a climatology on wave spectra during a 2-year mission. Major scientific objectives include a characterization of gravity waves and their interaction with larger-scale waves and mean flow in the mesosphere and lower thermosphere, as well as their relationship to dynamical conditions in the lower and upper atmosphere. MATS is currently being prepared to be ready for a launch in 2020. This paper provides an overview of scientific goals, measurement concepts, instruments, and analysis ideas.

The semiannual oscillation (SAO) in the tropical middle atmosphere and its gravity wave driving in reanalyses and satellite observations

“…Indeed, in a recent model intercomparison Smith et al (2020) concluded that in free-running general circulation models too weak gravity wave forcing would be one of the main reasons for misrepresentations of the SSAO. Still, because our gravity wave observations do not provide any directional information, the magnitudes of net gravity wave momentum flux and of net gravity wave drag remain an open issue that needs to be addressed by better global observations providing information about the full 3D structure of gravity waves (see also, for example, Preusse et al, 2014;Ern et al, 2017;Gumbel et al, 2020).…”

“…First observations of the SAO winds were made by rocketsondes and radars at single stations in the tropics (e.g., Reed, 1966;Groves, 1972;Hirota, 1978;Dunkerton, 1982;Hamilton, 1982;Palo and Avery, 1993), and observations at tropical stations are still continued (e.g., Gurubaran and Rajaram, 2001;Venkateswara Rao et al, 2012;Day and Mitchell, 2013;Kishore Kumar et al, 2014). Direct observations of the SAO winds from satellite were made, for example, by the High Resolution Doppler Imager (HRDI) aboard the Upper Atmosphere Research Satellite (UARS) (e.g., Lieberman et al, 1993;Burrage et al, 1996) or by the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) instrument aboard the International Space Station (e.g., Baron et al, 2013).…”

Comment on acp-2021-190 -- tidal forces

“…Further, the SABER observations in the stratopause region are roughly in agreement with lidar observations (e.g., Deepa et al, 2006;Antonita et al, 2007) that also cover only a certain part of the whole spectrum of gravity waves. Still, because our gravity wave observations do not provide any directional information, the magnitudes of net gravity wave momentum flux and of net gravity wave drag remain an open issue that needs to be addressed by better global observations providing information about the full 3D structure of gravity waves (see also, for example Preusse et al, 2014;Ern et al, 2017;Gumbel et al, 2020). Swinbank and Ortland, 2003;Randel et al, 2002Randel et al, , 2004.…”

Lower-thermosphere–ionosphere (LTI) quantities: current status of measuring techniques and models

“…While all global MHD simulations provide the ionospheric plasma drift pattern and the electric field, often the resulting polar cap potential can be overestimated (e.g. Haiducek et al, 2017), or underestimated (e.g. Palmroth et al, 2005) compared to best available measurements.…”