Gravity Waves in Planetary Atmospheres: Their Effects and Parameterization in Global Circulation Models

Abstract

The dynamical and thermodynamical importance of gravity waves was initially recognized in the atmosphere of Earth. Extensive studies over recent decades demonstrated that gravity waves exist in atmospheres of other planets, similarly play a significant role in the vertical coupling of atmospheric layers and, thus, must be included in numerical general circulation models. Since the spatial scales of gravity waves are smaller than the typical spatial resolution of most models, atmospheric forcing produced by them must be parameterized. This paper presents a review of gravity waves in planetary atmospheres, outlines their main characteristics and forcing mechanisms, and summarizes approaches to capturing gravity wave effects in numerical models. The main goal of this review is to bridge research communities studying atmospheres of Earth and other planets.

Gravity Wave Activity in the Atmosphere of Mars During the 2018 Global Dust Storm: Simulations With a High‐Resolution Model

“…They transport energy and momentum from denser tropospheres to thinner upper levels (Yiğit & Medvedev, 2019). Effects produced by GWs are particularly strong in the middle and upper atmospheres of Earth and Mars (see recent reviews of Medvedev & Yiğit, 2019; Yiğit & Medvedev, 2015, correspondingly), thus making them a major dynamical mechanism that couples the lower and upper atmospheres on both planets. Being relatively small in size (from tens to hundreds of kilometers in horizontal wavelength) and short‐lived (periods from a few minutes to several hours), GWs are thought to strongly affect the Martian global circulation.…”

“…Atmospheric models with conventional resolution (i.e., horizontal grid spacing of a few degrees in latitude and longitude) do not capture GWs and have to parameterize the effects of GWs as a subgrid‐scale process instead (Lott et al., 2012; Medvedev & Yiğit, 2019; Yiğit & Medvedev, 2017). These parameterizations require a specification for the wave sources in the lower atmosphere (i.e., representative phase speed for the waves, associated momentum fluxes, and launch altitude) that are not readily constrained from observations.…”

Variability of Gravity Wave Effects on the Zonal Mean Circulation and Migrating Terdiurnal Tide as Studied With the Middle and Upper Atmosphere Model (MUAM2019) Using a Nonlinear Gravity Wave Scheme

“…Various GW parameterizations have been developed so far (see reviews by Fritts and Alexander, 2003;Kim et al, 2003;Teixeira, 2014;Medvedev and Yigit, 2019). The majority of these schemes have been designed for middle atmosphere GCMs.…”

Density Fluctuations in the Lower Thermosphere of Mars Retrieved From the ExoMars Trace Gas Orbiter (TGO) Aerobraking

“…GWs are ubiquitous in the Martian and all other planetary atmospheres studied so far [3]. They have been detected at various altitudes during all seasons: in the lower atmosphere using remote sensing techniques such as radio occultations [4], dayglow imaging [5], and infrared radiometer [6], and in the upper atmosphere by in situ measurements with mass spectrometers, e.g., in [7][8][9], and satellite aerobraking [10,11].…”

“…GWs not only continuously disturb the atmosphere, but significantly affect its large-scale dynamics and thermal state. The essential role of these waves has originally been recognized in the terrestrial atmosphere (e.g., see reviews [13,14]), and their role in the general circulation of other planetary atmospheres is increasingly appreciated [3]. The first estimates of momentum forcing created by dissipating GWs in the Martian thermosphere have been inferred from Mars Global Surveyor (MGS) and Mars Odyssey (ODY) aerobraking densities [10].…”