Exploring Thermospheric Variability and Far-Ultraviolet Airglow Sensitivity: First Results from Ensemble Modeling with the Whole Atmosphere Model | CU Experts

Earth’s thermosphere is driven by a combination of meteorological,; magnetospheric, and solar forcing that exhibits significant variation; from day-to-day. The relative importance of these drivers and their; combined affects in determining daily thermospheric variability on; global and local scales is an important science question particularly; under solar minimum conditions. Far-ultraviolet, satellite-based airglow; observations are a valuable tool to probe the thermosphere and can; provide the spatial coverage and temporal resolution required to improve; our understanding of thermospheric day-to-day variability in response to; driver variability. This paper presents first results from principal; component analysis and ensemble sensitivity analysis to quantify the; major modes of dayglow variability in both OI 135.6 nm emissions and N2; Lyman-Birge-Hopfield emissions and the sensitivity of these modes to; geomagnetic and lower atmosphere drivers. The ensemble simulations are; performed with NOAA’s Whole Atmosphere Model that extends from Earth’s; surface to the exobase and NCAR’s Global Airglow Model for a recent; period with low-to-moderate levels of geomagnetic activity and low solar; activity. The ensemble simulations are compared to thermospheric; observations over the same period by the NASA Global-scale Observations; of the Limb and Disk (GOLD) mission.

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