Impacts of Gravity Wave on the thermosphere simulated by a whole atmosphere-ionosphere coupled Model
Abstract
It has been recognized that gravity wave (GW) plays an important role on the general circulation in the thermosphere. Upward propagating GW deposits energy and momentum in the thermosphere, and modifies the general circulation and composition in the thermosphere. In this study, using a whole atmosphere-ionosphere coupled model (GAIA), impacts of upward propagating GWs on the general circulation in the thermosphere are investigated. The GAIA contains the region from the ground surface to the upper thermosphere, so that we can simulate excitation of gravity waves in the lower atmosphere, their upward propagation to the thermosphere, and their impacts on the general circulation in the thermosphere. We have recently developed an atmosphere-ionosphere coupled model (GAIA) with high horizontal resolution (0.5 degree longitude by 0.5 degree latitude). In this study, we focus our attention on diurnal and latitudinal variations GW activity in the mesosphere and thermosphere. Our simulation result indicates that the GW drag in the thermosphere exceed 100 m/s/day, and has significant diurnal variations. The GW activity in the thermosphere is not uniformly distributed, and there are some GW activity "hot spots". For example, the peak of GW activity in June - August is located in 50-70ºS . This peak is closely related with the polar night jet in the stratosphere and mesosphere. On the other hand, the GW activity in December - February is active in high latitudes in the northern hemisphere, and is related with the planetary wave activity in the stratosphere and mesosphere.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2016
- Bibcode:
- 2016AGUFMSA32A..08M
- Keywords:
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- 3334 Middle atmosphere dynamics;
- ATMOSPHERIC PROCESSESDE: 3369 Thermospheric dynamics;
- ATMOSPHERIC PROCESSESDE: 3384 Acoustic-gravity waves;
- ATMOSPHERIC PROCESSESDE: 4490 Turbulence;
- NONLINEAR GEOPHYSICS