Martian Thermospheric Warming Associated With the Planet Encircling Dust Event of 2018

We report the first observations of Martian thermospheric warming associated with the Planet Encircling Dust Event (PEDE) of 2018. We used dayglow observations made by the Imaging Ultraviolet Spectrograph instrument aboard the MAVEN spacecraft to retrieve the upper atmosphere temperature structures. Our analysis shows that the two-cell meridional circulation pattern may be operating before the PEDE-2018, which resulted in the cooling of lower/middle latitudes and warming at higher latitudes. However, after the onset, the existing circulation pattern gets dampened, resulted in a weaker latitudinal temperature structure. We saw that mean temperatures rose by about 20 K for the same local time after the onset of the dust storm. Our 3-D Mars General Ionosphere Thermosphere Model calculations were able to reproduce the temperatures during the predust and early dust storm but failed to fully capture the temperature trend during the growth phase of the PEDE of 2018. ©2020. American Geophysical Union. All Rights Reserved.This research was supported by NASA through the MAVEN project. The periapse data used in this analysis are archived (with version/revision tag v13_r01) in NASA's Planetary Data System (PDS). The side segment limb data used in the work will be archived in the FAIR-compliant CU Scholar Repository (https://scholar.colorado.edu). This work utilized the RMACC Summit supercomputer, which is supported by the National Science Foundation (Awards ACI-1532235 and ACI-1532236). The Summit supercomputer is a joint effort of the University of Colorado Boulder and Colorado State University. M-GITM calculations utilized the NASA NAS Pleiades supercomputer; subsequent model outputs used for data-model comparisons are available on the Deep Blue Data repository at the University of Michigan Library (https://doi.org/10.7302/8qkz-1z09). The work at the Jet Propulsion Laboratory, California Institute of Technology was performed under a contract with the National Aeronautics and Space Administration. Government sponsorship is acknowledged. The MCS data set used in this work is freely available from NASA's Planetary Data System (PDS). F.G.G. is funded by the Spanish Ministerio de Ciencia, Innovaci?n y Universidades, the Agencia Estatal de Investigacion and EC FEDER funds under project RTI2018-100920-J-I00, and acknowledges financial support from the State Agency for Research of the Spanish MCIU through the ?Center of Excellence Severo Ochoa? award to the Instituto de Astrof?sica de Andaluc?a (SEV-2017-0709).Peer reviewe