DOI: 10.7302/8qkz-1z09
title: Mars Thermospheric Responses to a Global Dust Storm (PEDE-2018):  Mars Global Ionosphere-Thermosphere Model (M-GITM) Simulated Datasets for Comparison to MAVEN Spacecraft Measurements

description: The NASA MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, which is currently in orbit around Mars, has been taking daily (systematic) measurements of the densities and temperatures  in the upper atmosphere of Mars between about 140 to 240 km above the surface.  Wind measurement campaigns are also conducted once per month for 5-10 orbits. These densities, temperatures and winds change with time (e.g. season, local time) and location, and sometimes fluctuate quickly. Global dust storm events are also known to significantly impact these density, temperature and wind fields in the Mars thermosphere. Such global dust storm period measurements can be compared to simulations from a computer model of the Mars atmosphere called M-GITM (Mars Global Ionosphere-Thermosphere Model), developed at U. of Michigan. This is the first detailed comparison between direct  global dust storm period measurements in the upper atmosphere of Mars and simulated MGITM fields  and is important because it can help to inform us what physical processes are acting on the upper atmosphere during such large dust events.  Since the global circulation plays a role in the structure, variability, and evolution of the atmosphere, understanding the processes that drive the winds in the upper atmosphere of Mars also provides key context for understanding how the atmosphere behaves as a whole system. A basic version of the M-GITM code can be found on Github as follows: https:/github.com/dpawlows/MGITM

;About 4 months of Neutral Gas and Ion Mass Spectrometer (NGIMS) measurements of densities and winds have been made by the MAVEN team during the summer of 2018 (Elrod et al., 2019). Nine reference measurement intervals during this global dust storm (1-June through 30-August 2018) are selected for detailed study (Elrod et al. 2019). The Mars conditions for these nine intervals have been used to launch corresponding M-GITM code simulations, yielding 3-D neutral density, temperature and wind fields for comparison to these NGIMS measurements. The M-GITM datacubes used to extract the density, temperature and neutral winds, along the trajectory of each orbit path between 140 and 240 km, are provided in this Deep Blue Data archive. README files are provided for each datacube, detailing the contents of each file. A general README file is also provided that summarizes the inputs and outputs of the M-GITM code simulations for this study.
description: Simulated composition, temperatures and neutral winds of the Mars thermosphere are calculated by the 3-D numerical model called M-GITM (Mars Global Ionosphere-Thermosphere Model), developed at the U. of Michigan. This is a climate model whose domain extends from the surface to ~250 km (Bougher et al., 2015). Neutral plus ion densities, neutral temperatures and winds are calculated on a 3-D grid (latitude, longitude, altitude) for NASA MAVEN spacecraft conditions corresponding to specific instrument measurements made. These 3-D model calculations are time-marching, making use of a finite-difference code which solves the Navier-Stokes equations for temperatures, composition, and winds. Large datacubes are created of M-GITM outputs fields for deposit on this archive