The Vertical Dust Profile over Gale Crater

S. Guzewich, C. E. Newman, M. D. Smith, J. Moores, C. L. Smith, C. Moore, M. I. Richardson, D. M. Kass, A. Kleinboehl, F. J. Martin-Torres, M. P. Zorzano, J. M. Battalio

Research output: Contribution to conferencePaper

Abstract

Regular joint observations of the atmosphere over Gale Crater from the orbiting Mars Reconnaissance Orbiter/Mars Climate Sounder (MCS) and Mars Science Laboratory (MSL) Curiosity rover allow us to create a coarse, but complete, vertical profile of dust mixing ratio from the surface to the upper atmosphere. We split the atmospheric column into three regions: the planetary boundary layer (PBL) within Gale Crater that is directly sampled by MSL (typically extending from the surface to 2-6 km in height), the region of atmosphere sampled by MCS profiles (typically 25-80 km above the surface), and the region of atmosphere between these two layers. Using atmospheric optical depth measurements from the Rover Environmental Monitoring System (REMS) ultraviolet photodiodes (in conjunction with MSL Mast Camera solar imaging), line-of-sight opacity measurements with the MSL Navigation Cameras (NavCam), and an estimate of the PBL depth from the MarsWRF general circulation model, we can directly calculate the dust mixing ratio within the Gale Crater PBL and then solve for the dust mixing ratio in the middle layer above Gale Crater but below the atmosphere sampled by MCS. Each atmospheric layer has a unique seasonal cycle of dust opacity, with Gale Crater's PBL reaching a maximum in dust mixing ratio near Ls = 270° and a minimum near Ls = 90°. The layer above Gale Crater, however, has a seasonal cycle that closely follows the global opacity cycle and reaches a maximum near Ls = 240° and exhibits a local minimum (associated with the "solsticial pauses") near Ls = 270°. Knowing the complete vertical profile also allows us to determine the frequency of high-altitude dust layers above Gale, and whether such layers truly exhibit the maximum dust mixing ratio within the entire vertical column. We find that 20% of MCS profiles contain an "absolute" high-altitude dust layer, i.e., one in which the dust mixing ratio within the high-altitude dust layer is the maximum dust mixing ratio in the vertical column of atmosphere over Gale Crater.

Original languageEnglish
Publication statusPublished - 1 Dec 2017
Event2017 American Geophysical Union Fall Meeting - New Orleans, United States
Duration: 11 Dec 201715 Nov 2018

Conference

Conference2017 American Geophysical Union Fall Meeting
CountryUnited States
CityNew Orleans
Period11/12/1715/11/18

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Keywords

  • 3346 Planetary meteorology
  • ATMOSPHERIC PROCESSES
  • 6225 Mars
  • PLANETARY SCIENCES: SOLAR SYSTEM OBJECTS
  • 5405 Atmospheres
  • PLANETARY SCIENCES: SOLID SURFACE PLANETS
  • 5445 Meteorology

Cite this

Guzewich, S., Newman, C. E., Smith, M. D., Moores, J., Smith, C. L., Moore, C., Richardson, M. I., Kass, D. M., Kleinboehl, A., Martin-Torres, F. J., Zorzano, M. P., & Battalio, J. M. (2017). The Vertical Dust Profile over Gale Crater. Paper presented at 2017 American Geophysical Union Fall Meeting, New Orleans, United States. https://ui.adsabs.harvard.edu/abs/2017AGUFM.P23D2758G