Satellite observations of middle atmosphere-Thermosphere vertical coupling by gravity waves
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In this paper, the authors analyzed the correlation between GW momentum fluxes observed in the middle atmosphere and GW-induced perturbations in the T/I system and found generally positive correlations between horizontal distributions at low altitudes (i.e., below 90 km ) and horizontal distributions of GW induced density fluctuations in the t/I (at ≥ 200 km and above) and concluded that two coupling mechanisms are likely responsible for these positive correlations: (1) fast GWs generated in the troposphere and lower stratosphere can propagate directly to the T /I and (2Abstract:
. Atmospheric gravity waves (GWs) are essential for the dynamics of the middle
atmosphere. Recent studies have shown that these waves are also important for
the thermosphere/ionosphere (T/I) system. Via vertical coupling, GWs can
significantly influence the mean state of the T/I system. However, the
penetration of GWs into the T/I system is not fully understood in modeling as
well as observations. In the current study, we analyze the correlation
between GW momentum fluxes observed in the middle atmosphere
(30–90 km ) and GW-induced perturbations in the T/I. In the middle
atmosphere, GW momentum fluxes are derived from temperature observations of
the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER)
satellite instrument. In the T/I, GW-induced perturbations are derived from
neutral density measured by instruments on the Gravity field and Ocean
Circulation Explorer (GOCE) and CHAllenging Minisatellite Payload (CHAMP)
satellites. We find generally positive correlations between horizontal
distributions at low altitudes (i.e., below 90 km ) and horizontal
distributions of GW-induced density fluctuations in the T/I (at
200 km and above). Two coupling mechanisms are likely responsible for
these positive correlations: (1) fast GWs generated in the troposphere and
lower stratosphere can propagate directly to the T/I and (2) primary GWs with
their origins in the lower atmosphere dissipate while propagating upwards and
generate secondary GWs, which then penetrate up to the T/I and maintain the
spatial patterns of GW distributions in the lower atmosphere. The
mountain-wave related hotspot over the Andes and Antarctic Peninsula is found
clearly in observations of all instruments used in our analysis.
Latitude–longitude variations in the summer midlatitudes are also found in
observations of all instruments. These variations and strong positive
correlations in the summer midlatitudes suggest that GWs with origins related
to convection also propagate up to the T/I. Different processes which likely
influence the vertical coupling are GW dissipation, possible generation of
secondary GWs, and horizontal propagation of GWs. Limitations of the
observations as well as of our research approach are discussed. Keywords. Ionosphere (ionosphere–atmosphere interactions)read more
Citations
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Journal ArticleDOI
Numerical Modeling of the Generation of Tertiary Gravity Waves in the Mesosphere and Thermosphere During Strong Mountain Wave Events Over the Southern Andes
Sharon L. Vadas,Erich Becker +1 more
TL;DR: In this paper, the effects on the mesosphere and thermosphere from a strong mountain wave (MW) event over the wintertime Southern Andes using a gravity wave (GW)-resolving global circulation model were investigated.
Journal ArticleDOI
Explicit global simulation of gravity waves in the thermosphere
Erich Becker,Sharon L. Vadas +1 more
TL;DR: In this article, a new version of the high-resolution Kühlungsborn Mechanistic general Circulation Model (KMCM) extended to z∼ 450 km is presented.
Journal ArticleDOI
Characteristics of the Quiet-Time Hot Spot Gravity Waves Observed by GOCE Over the Southern Andes on 5 July 2010
TL;DR: In this paper, the 20 largest traveling atmospheric disturbances from the density perturbations and cross-track winds using Fourier analysis were extracted from the satellite data using gravity wave dissipative theory that includes realistic molecular viscosity.
Journal Article
A comprehensive observational filter for satellite infrared limb sounding of gravity waves
Thai Trinh,Hye-Yeong Chun,Silvio Kalisch,Martin Riese,Stephen D. Eckermann,Manfred Ern,Peter Preusse +6 more
TL;DR: In this paper, a comprehensive observational filter for satellite infrared limb sounding of gravity waves is described, which includes four main processes: visibility filter, projection of the wavelength on the tangent-point track, aliasing effect, and calculation of the observed vertical wavelength.
Journal ArticleDOI
First Direct Observational Evidence for Secondary Gravity Waves Generated by Mountain Waves over the Andes
Masaru Kogure,Jia Yue,Jia Yue,Takuji Nakamura,Takuji Nakamura,Lars Hoffmann,Sharon L. Vadas,Yoshihiro Tomikawa,Yoshihiro Tomikawa,Mitsumu K. Ejiri,Mitsumu K. Ejiri,Diego Janches +11 more
TL;DR: In this article, the authors provided the first direct evidence for secondary gravity waves generated by momentum deposition from breaking mountain waves and support the vertical multistep coupling mechanism, which is likely important for creating ionospheric disturbances in the F region.
References
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