Convective vortices and dust devils at the MSL landing site: Annual variability. Issue 8 (29th August 2016)

• Record Type: Journal Article
• Authors: Kahanpää, H.; Newman, C.; Moores, J.; Zorzano, M.‐P.; Martín‐Torres, J.; Navarro, S.; Lepinette, A.; Cantor, B.; Lemmon, M. T.; Valentín‐Serrano, P.; Ullán, A.; Schmidt, W.
• Is Part Of: Journal of geophysical research. Volume 121:Issue 8(2016:Aug.)
• Page Start: 1514
• Page End: 1549
• Publication Date: 2016-08-29
• Subjects: Mars -- dust devils -- convective vortices -- planetary atmospheres -- numerical modeling; Planets -- Periodicals; Geophysics -- Periodicals; 559.9
• DOI: 10.1002/2016JE005027
• Languages: English
• ISSNs: 2169-9097

Abstract

Abstract: Two hundred fifty‐two transient drops in atmospheric pressure, likely caused by passing convective vortices, were detected by the Rover Environmental Monitoring Station instrument during the first Martian year of the Mars Science Laboratory (MSL) landed mission. These events resembled the vortex signatures detected by the previous Mars landers Pathfinder and Phoenix; however, the MSL observations contained fewer pressure drops greater than 1.5 Pa and none greater than 3.0 Pa. Apparently, these vortices were generally not lifting dust as only one probable dust devil has been observed visually by MSL. The obvious explanation for this is the smaller number of strong vortices with large central pressure drops since according to Arvidson et al . [2014 ] ample dust seems to be present on the surface. The annual variation in the number of detected convective vortices followed approximately the variation in Dust Devil Activity (DDA) predicted by the MarsWRF numerical climate model. This result does not prove, however, that the amount of dust lifted by dust devils would depend linearly on DDA, as is assumed in several numerical models of the Martian atmosphere, since dust devils are only the most intense fraction of all convective vortices on Mars, and the amount of dust that can be lifted by a dust devil depends on its central pressure drop. Sol‐to‐sol variations in the number of vortices were usually small. However, on 1 Martian solar day a sudden increase in vortex activity, related to a dust storm front, was detected. Key Points: Signs of 252 dustless convective vortices have been detected by Mars Science Laboratory The annual variation in vortex occurrence rate followed approximately dust devil activity predicted by a numerical climate model A transient increase in vortex activity related to a dust storm front was detected by meteorological measurements on Mars