CEDAR: The Role of Gravity Waves in Coupling Longitudinal Variations in the Troposphere to the Thermosphere and Ionosphere

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This is a data analysis and modeling effort to be undertaken as part of the Coupling, Energetics and Dynamics of Atmospheric Regions program. Atmospheric waves are one means by which energy and momentum can be transported between different layers of the atmosphere. Recent results show that the source of non-migrating tidal waves in the atmosphere -- the uneven distribution of deep cell convection zones in the troposphere associated with the land-sea contrast -- also gives rise to a varying source of atmospheric gravity waves. The main goal of this effort is to quantify this source and its potential effects, which is currently missing from models of the upper atmosphere and ionosphere and may force a revision in our understanding of how the apparent tidal signature in the ionosphere is driven by waves in the atmosphere. Global datasets of temperature and wind from satellite observations together with several advanced global atmospheric and ionospheric circulation models will be used to determine the spatial, temporal and spectral characteristics of large-scale gravity waves, their global effects on tidal variation, and the ionospheric impacts. Gravity waves are a significant forcing source on Mesosphere-Lower Thermosphere (MLT) dynamics and their effects strongly impact general circulation and climate models. In addition, numerical weather prediction models, despite their tropospheric focus, have been shown to make better predictions when the upper-atmospheric dynamics are more accurately modeled. The work will be performed mainly by a post-doctoral scholar and a graduate student, both mentored by the principal investigator (PI), and in collaboration with data-analysis and modeling experts at Berkeley and at NCAR.