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Investigation of Thermospheric Response to Geomagnetic Storms Using GITM-OVATION Prime and -FTA model With Comparison to GOLD and SABER Observations
  • Atishnal Elvin Chand,
  • George William Bowden,
  • Melrose Brown
Atishnal Elvin Chand
University of New South Wales Canberra

Corresponding Author:[email protected]

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George William Bowden
University of New South Wales Canberra
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Melrose Brown
University of New South Wales Canberra
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Abstract

Global Ionosphere Thermosphere Model (GITM) results have been compared with measurements from Global-scale Observations of the Limb and Disk (GOLD) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER). For the first time, GOLD-derived exospheric temperature and column-integrated O/N$_2$ ratio measurements have been used to validate GITM model results. We examine two geomagnetic storm events for which we drive GITM with space weather conditions to understand how well the model reproduces the thermospheric responses to geomagnetic activity. In this paper, a recently developed auroral model, the Feature Tracking of Aurora (FTA) model, has been employed to calculate auroral electron precipitation in GITM (GITM w/FTA), and results are compared with the OVATION prime (OP) driven GITM model (GITM w/OP). GITM w/FTA simulated temperature, neutral density, and nitric oxide (NO) density are generally higher compared to the GITM w/OP model. During the geomagnetic storm, the GITM model and GOLD-derived exospheric temperature agree between $\sim$$0^{\circ}$ to $5^{\circ}$N latitude in the equatorial region. GOLD measurements show strong O/N$_2$ peaks and two distinct equatorial zones during the geomagnetic storm period, which is also observed in our model results. During geomagnetic storm conditions, there is an upward shift in the peak altitude profile of NO emission by up to $\approx$10 km. The NO cooling peaks estimated by GITM models are $\sim$20 km lower than SABER observations during geomagnetic storms. The SABER-derived NO emission is better reproduced by the GITM w/FTA model than by the GITM w/OP model during geomagnetic storms at high latitudes.
22 Aug 2024Submitted to ESS Open Archive
22 Aug 2024Published in ESS Open Archive