The Vertical Dust Profile Over Gale Crater, Mars. Issue 12 (19th December 2017)

• Record Type: Journal Article
• Authors: Guzewich, Scott D.; Newman, C. E.; Smith, M. D.; Moores, J. E.; Smith, C. L.; Moore, C.; Richardson, M. I.; Kass, D.; Kleinböhl, A.; Mischna, M.; Martín‐Torres, F. J.; Zorzano‐Mier, M.‐P.; Battalio, M.
• Is Part Of: Journal of geophysical research. Volume 122:Issue 12(2017)
• Page Start: 2779
• Page End: 2792
• Publication Date: 2017-12-19
• Subjects: Mars -- atmosphere -- dust -- Curiosity -- MSL -- Gale Crater; Planets -- Periodicals; Geophysics -- Periodicals; 559.9
• DOI: 10.1002/2017JE005420
• Languages: English
• ISSNs: 2169-9097

Abstract

Abstract: We create a vertically coarse, but complete, profile of dust mixing ratio from the surface to the upper atmosphere over Gale Crater, Mars, using the frequent joint atmospheric observations of the orbiting Mars Climate Sounder (MCS) and the Mars Science Laboratory Curiosity rover. Using these data and an estimate of planetary boundary layer (PBL) depth from the MarsWRF general circulation model, we divide the vertical column into three regions. The first region is the Gale Crater PBL, the second is the MCS‐sampled region, and the third is between these first two. We solve for a well‐mixed dust mixing ratio within this third (middle) layer of atmosphere to complete the profile. We identify a unique seasonal cycle of dust within each atmospheric layer. Within the Gale PBL, dust mixing ratio maximizes near southern hemisphere summer solstice ( L s = 270°) and minimizes near winter solstice ( L s = 90–100°) with a smooth sinusoidal transition between them. However, the layer above Gale Crater and below the MCS‐sampled region more closely follows the global opacity cycle and has a maximum in opacity near L s = 240° and exhibits a local minimum (associated with the "solsticial pause" in dust storm activity) near L s = 270°. With knowledge of the complete vertical dust profile, we can also assess the frequency of high‐altitude dust layers over Gale. We determine that 36% of MCS profiles near Gale Crater contain an "absolute" high‐altitude dust layer wherein the dust mixing ratio is the maximum in the entire vertical column. Key Points: We calculate a complete vertical profile of dust above Gale Crater from the surface to upper atmosphere Each of the three atmospheric layers exhibits a unique seasonal cycle in dust opacity and mixing ratio The 36% of MCS profiles over Gale Crater contain a high‐altitude dust layer