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bougher@umich.edu
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- Creator:
- Bougher, Stephen W. and Roeten, Kali J.
- 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 an ongoing 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 [less] 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; Roeten et al 2022). For this specialized archive (Elrod et al. 2023), one reference measurement interval during this 2018 global dust storm (30-31 August 2018) is selected for detailed study of helium distributions (Elrod et al. 2023). The Mars conditions for this last of 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. This last interval is used to provide M-GITM datacubes to explicitly extract the helium density (plus corresponding temperatures and neutral winds) along the trajectory of each orbit path between 140 and 240 km . A general README file is also provided for this Deep Blue Data archive detailing the contents of each file, while also summarizing the inputs and outputs of the M-GITM code simulations for this study.
- Keyword:
- Mars , NASA MAVEN spacecraft, Mars Thermosphere, Global Dust Strom of 2018, and Helium distribution
- Citation to related publication:
- Elrod, M. K., S. W. Bougher, K. Roeten, R. Sharrar, J. Murphy, Structural and Compositional Changes in the Upper Atmosphere related to the PEDE-2018 Dust Event on Mars as Observed by MAVEN NGIMS, Geophys. Res. Lett., (2019). doi: 10.1029/2019GL084378. and Elrod, M. K., S. W. Bougher, K. Roeten and K. Arnold, Surprising Decrease in the Martian He Bulge during PEDE-2018 and Changes in Upper Atmospheric Circulation, J. Geophysical Research, (2023), doi:XXX
- Discipline:
- Science
-
- Creator:
- Bougher, Stephen W. and Roeten, Kali J.
- Description:
- The NASA MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, which is currently in orbit around Mars, has been taking systematic measurements of the densities and deriving temperatures in the upper atmosphere of Mars between about 140 to 240 km above the surface since late 2014. Wind measurement campaigns are also conducted once per month for 5-10 orbits. These densities, temperatures and winds change with time (e.g. solar cycle, 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. For the current project, the derived temperatures and O plus CO2 densities are used to characterize the upper atmosphere dayside thermal and density structure. Presently, more than 6 years of Neutral Gas and Ion Mass Spectrometer (NGIMS) measurements of neutral densities have been obtained by the MAVEN team (e.g. Mahaffy et al. 2015; Bougher et al 2015; Elrod et al., 2017; 2021; Stone et al. 2018; Gupta et al., 2021). Measured neutral density distributions are compared to simulations from a computer model of the Mars atmosphere called M-GITM (Mars Global Ionosphere-Thermosphere Model), developed at U. of Michigan. 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 the needed context for understanding density and temperature distributions and how the atmosphere behaves as a whole system. Three dimensional M-GITM simulations for extreme Mars seasonal and solar cycle conditions were conducted for detailed comparisons with NGIMS derived temperatures and O/CO2 ratio distributions (Bougher et al. 2022). Extracted model densities and temperatures along the MAVEN inbound trajectory of each orbit path (between ~300 km and periapsis) are provided in this Deep Blue Data archive. Corresponding M-GITM heat balance terms are also provided in vertical 1-D tabulated formats. README files are included for each suite of 1-D "flythru" tables, detailing the contents of each file. In addition, a general README file is provided that summarizes the inputs and outputs of the M-GITM code simulations for this study. Finally, a basic version of the M-GITM code can be found on Github at https:/github.com/dpawlows/MGITM.
- Keyword:
- Mars, NASA MAVEN Mission, NGIMS instrument , and M-GITM numerical simulations
- Citation to related publication:
- Bougher, S. W., Benna, M., Elrod, M., Roeten, K., & Thiemann, E. (2023). MAVEN/NGIMS dayside exospheric temperatures over solar cycle and seasons: Role of dayside thermal balances in regulating temperatures. Journal of Geophysical Research: Planets, 128, e2022JE007475. https://doi.org/10.1029/2022JE007475
- Discipline:
- Science
-
- Creator:
- Bougher, S. W. and Parkinson, C. D.
- Description:
- Understanding the state and composition of an exoplanetary atmosphere depends upon several parameters such as heating, cooling, mixing and reactions between constituent chemical species. Only a few types of atmospheric species can be detected remotely spectroscopically and only if their abundance is large enough to be detectable. In this initial study, we model the atmosphere of a Venus-like planet orbiting the M-type star GJ 436 to determine the global neutral temperature structure, winds, and energy balance as the radial distance of the planet from the star decreases.
- Keyword:
- Venus-like exoplanet, upper atmospheres , and heat balances
- Citation to related publication:
- C. D. Parkinson, S. W. Bougher, F. P. Mills, R. Hu, G. Gronoff, J. Li, A. Brecht, D. Adams, and Y. L. Yung. Venus as an Exoplanet: I. An Initial Exploration of the 3-D Energy Balance for a CO2 Exoplanetary Atmosphere Around an M-Dwarf Star, J. Geophysical Research, X, (2022). doi:....
- Discipline:
- Science
-
Dynamical Heating in the Martian Thermosphere: Temperatures, Winds and Thermal Balances using M-GITM
- Creator:
- Bougher, S. W. and Pilinski, M. D.
- Description:
- The NASA MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, which is currently in orbit around Mars, has been taking systematic measurements of the densities and deriving temperatures in the upper atmosphere of Mars (between about 140 to 240 km above the surface) since late 2014. Wind measurement campaigns have also been conducted once per month for 5-10 orbits since 2016. These densities, temperatures and winds change with time (e.g. solar cycle, 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. For the current project, in-situ measured winds and corresponding argon density derived temperatures are combined to trace the circulation patterns and investigate their convergence and divergence locations and impacts throughout the Mars thermosphere. M-GITM computed thermal balance terms are subsequently extracted to investigate the processes required to maintain the temperature distribution around the planet. For this work, Mars Year #33 (MY33) Neutral Gas and Ion Mass Spectrometer (NGIMS) measurements have been obtained by the MAVEN team for this purpose (see these representative works: (Bougher et al., 2017; Stone et al., 2018; Benna et al., 2019). These temperature and wind fields are compared to simulations from a computer model of the Mars atmosphere called M-GITM (Mars Global Ionosphere-Thermosphere Model), developed at U. of Michigan. 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 the needed context for understanding temperature distributions and underlying thermal balances throughout the atmosphere. Three dimensional M-GITM simulations for three of the four Mars cardinal seasons (Ls = 0, 90, 270) for MY33 were conducted for detailed comparisons with NGIMS temperature and wind distributions (Pilinski et al. 2022). Corresponding M-GITM datacubes used to extract these temperatures (plus winds) along the trajectory of each orbit path between 140 and 240 km, are provided in this Deep Blue Data archive. A single README file is included that details the contents of each datacube file. In addition, this general README file summarizes the inputs and outputs of each M-GITM simulation interval used for this study. Finally, a basic version of the M-GITM code can be found on Github at https:/github.com/dpawlows/MGITM.
- Keyword:
- MAVEN, Mars thermosphere, global dynamics, and heat balances owing to winds
- Citation to related publication:
- Pilinski, M. D., K. J. Roeten, S. W. Bougher and M. Benna, Dynamical Heating in the Martian Thermosphere, Journal Geophysical Res., XXX, (forthcoming - 2022). doi: .....
- Discipline:
- Science
-
- Creator:
- Bougher, S. W. (University of Michigan) and Brecht, A. S. (NASA Ames Research Center)
- Description:
- This work examines the planetary wave-induced variability within the upper mesosphere/lower thermosphere of Venus by utilizing the Venus Thermospheric General Circulation Model (VTGCM). Rossby and Kelvin wave perturbations are driven by variations in the geopotential height of the VTGCM lower boundary (~70 km). A suite of simulations was conducted to examine the impact of the individual and combined waves propagating from two different lower boundary conditions (uniform and varying). The Kelvin wave is the more dominant wave which produces the most variability, as was shown in Hoshino et al., 2012. The combination of the Kelvin and Rossby waves provides a maximum temperature amplitude of 13 K at 92 km and maximum zonal wind amplitude of 23 m/s at 102 km. The combined waves overall are able to propagate up to 125 km. Most of the variation within the temperature, winds, and composition occurs between 70 km and 110 km. The varying lower boundary increases the magnitude of the wave deposition but weakly changes the propagation altitude. The thermal variation due to the planetary waves does not reproduce most observed variations. The simulated O2 IR nightglow emission is sensitive to the waves with respect to intensity and local time, but lacks latitudinal variation. The integrated intensity ranges from 1.2 MR to 1.65 MR and the local time ranges from 0.33 local time to 23.6 local time. Overall, planetary waves do affect the atmospheric structure, but there are still observed large variations that planetary waves alone cannot explain (i.e. thermal structure).
- Keyword:
- Venus, planetary waves, upper mesophere, lower thermosphere, and O2 nightglow
- Citation to related publication:
- Brecht, A. S., Bougher, S. W., Shields, D., & Liu, H.-L. (2021). Planetary-scale wave impacts on the Venusian upper mesosphere and lower thermosphere. Journal of Geophysical Research: Planets, 126, e2020JE006587. https://doi.org/10.1029/2020JE006587
- Discipline:
- Science
-
- Creator:
- Bougher, S. W. (CLaSP Department, University of Michigan)
- Description:
- The NASA MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, which is currently in orbit around Mars, has been taking systematic measurements of the densities and deriving temperatures in the upper atmosphere of Mars between about 140 to 240 km above the surface since late 2014. Wind measurement campaigns are also conducted once per month for 5-10 orbits. These densities, temperatures and winds change with time (e.g. solar cycle, 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. For the current project, the inert light species helium is used to trace the circulation patterns and constrain wind magnitudes throughout the Mars thermosphere. Presently, more than 6 years of Neutral Gas and Ion Mass Spectrometer (NGIMS) measurements of helium densities have been obtained by the MAVEN team (e.g. Elrod et al., 2017; 2021; Gupta et al., 2021). Measured helium distributions are compared to simulations from a computer model of the Mars atmosphere called M-GITM (Mars Global Ionosphere-Thermosphere Model), developed at U. of Michigan. 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 the needed context for understanding helium distributions and how the atmosphere behaves as a whole system. Three dimensional M-GITM simulations for the Mars four cardinal seasons (Ls = 0, 90, 180, 270, for Mars Year 33) were conducted for detailed comparisons with NGIMS helium and CO2 distributions (Gupta et al. 2021). The M-GITM datacubes used to extract these densities (plus winds) along the trajectory of each orbit path between 140 and 240 km, are provided in this Deep Blue Data archive. README files are also provided for each datacube, detailing the contents of each file. In addition, a general README file is provided that summarizes the inputs and outputs of the M-GITM code simulations for this study. Finally, a basic version of the M-GITM code can be found on Github at https:/github.com/dpawlows/MGITM.
- Keyword:
- Mars, MAVEN Spacecraft Mission, Mars Thermosphere, Helium Density Distributions, and Neutral Gas and Ion Mass Spectrometer (NGIMS)
- Citation to related publication:
- Gupta, N., N. V. Rao, S. W. Bougher, and M. K. Elrod, Latitudinal and Seasonal Asymmetries of the Helium Bulge in the Martian Upper Atmosphere J. Geophys. Res., 126, XXXX-XXXX. doi:10.1002/2021JEXXXXXX
- Discipline:
- Engineering and Science
-
- Creator:
- Bougher, S. W. (CLaSP Department, U. of Michigan), Roeten, K. J. (CLaSP Department, U. of Michigan), and Sharrar, R. (Astronomy Department, U. of Michigan)
- 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 and 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.
- Keyword:
- Mars, MAVEN Spacecraft, Mars Thermosphere, and Mars Global Dust Storm of 2018
- Citation to related publication:
- Elrod, M. K., S. W. Bougher, K. Roeten, R. Sharrar, J. Murphy, Structural and Compositional Changes in the Upper Atmosphere related to the PEDE-2018 Dust Event on Mars as Observed by MAVEN NGIMS, Geophys. Res. Lett., (2019). doi: 10.1029/2019GL084378. and Jain, S. K., Bougher, S. W., Deighan, J., Schneider, N. M., Gonzalez‐Galindo, F., Stewart, A. I. F., et al. ( 2020). Martian thermospheric warming associated with the Planet Encircling Dust Event of 2018. Geophysical Research Letters, 47, e2019GL085302. https://doi.org/10.1029/2019GL085302
- Discipline:
- Engineering and Science
-
- Creator:
- Bougher, Stephen W. (CLaSP Department, U. of Michigan) and Roeten, Kali J. (CLaSP Department, U. of Michigan)
- Description:
- The NASA MAVEN (Mars Atmosphere and Volatile Evolution) spacecraft, which is currently in orbit around Mars, has been taking monthly measurements of the speed and direction of the winds in the upper atmosphere of Mars between about 140 to 240 km above the surface. The observed wind speeds and directions change with time and location, and sometimes fluctuate quickly. These measurements are 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 comparison between direct measurements of the winds in the upper atmosphere of Mars and simulated winds and is important because it can help to inform us what physical processes are acting on the observed winds. Some wind measurements have similar wind speeds or directions to those predicted by the M-GITM model, but sometimes, there are large differences between the simulated and measured winds. The disagreements between wind observations and model simulations suggest that processes other than normal solar forcing may become relatively more important during these observations and alter the expected circulation pattern. 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 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 and About 30 Neutral Gas and Ion Mass Spectrometer (NGIMS) wind campaigns (of 5 to 10 orbits each) have been conducted by the MAVEN team (Benna et al., 2019). Five of these campaigns are selected for detailed study (Roeten et al. 2019). The Mars conditions for these five campaigns have been used to launch corresponding M-GITM code simulations, yielding 3-D neutral wind fields for comparison to these NGIMS wind observations. The M-GITM datacubes used to extract the zonal and meridional 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.
- Keyword:
- Mars, MAVEN spacecraft, Mars thermosphere, and Mars global upper atmosphere winds
- Citation to related publication:
- Roeten, K. J., Bougher, S. W., Benna, M., Mahaffy, P. R., Lee, Y., Pawlowski, D., et al. (2019). MAVEN/NGIMS thermospheric neutral wind observations: Interpretation using the M‐GITM general circulation model. Journal of Geophysical Research: Planets, 124, 3283– 3303. https://doi.org/10.1029/2019JE005957
- Discipline:
- Science and Engineering