SA036-0016
Thermospheric data-model comparison using GOLD’s solar eclipse observations
Thermospheric data-model comparison using GOLD’s solar eclipse observations
Wednesday, 16 December 2020
Poster
Abstract:
Solar eclipses impulsively drive the thermosphere by briefly attenuating the high energy X-ray and UV solar radiation that heat and ionize it. Thermospheric observations of such impulsive events, thus, provide us better understanding of the thermosphere and the thermosphere-ionosphere (T-I) system. However, until recently synoptic observations of an eclipse in the thermosphere had not been made. NASA’s Global-scale Observation of Limb and Disk’s (GOLD) made such observations during the July 2, 2019 total solar eclipse. These first-of-a-kind observations show that the eclipse induced significant compositional (factor of 1.8) and neutral temperature changes (~ 150 K) near the totality when compared to the baseline observations made a couple of days prior. GOLD observations were simulated using the Thermospheric Ionospheric Electrodynamics General Circulation Model (TIE-GCM) and GLobal airglOW (GLOW) model. The simulations significantly underestimated compositional (by a factor of 1.6) and temperature (by > 100K) changes near the totality when compared to observations. These discrepancies show inadequacies in current knowledge of the Earth’s thermosphere and its modelling. Resolving these data-model disagreements has the potential to revolutionize the understanding of the thermosphere.