The whirlwinds of Elysium: A catalog and meteorological characteristics of “dust devil” vortices observed by InSight on Mars

Abstract

A catalog of convective vortex encounters recorded by InSight on the Martian surface is presented, through Sol 390 of the mission. The catalog summarizes key meteorological parameters such as wind speed and direction before the event, peak wind, the duration and magnitude of the pressure excursion, temperatures and solar array data where present. Additional seismic parameters are also provided on seismometer-detected ground acceleration. The catalog is intended as a resource for vortex population studies, and as an index for examining these meteorological events in detail and to assess possible geophysical (seismic or magnetic) signatures. Whereas it is difficult to evaluate 'anecdotal' results in small surveys, the large number of events (853 with a pressure drop exceeding 0.8 Pa) in this work permits robust statistical evaluation. For example, it is found that three times as many pressure profiles have slower onsets than decays than vice versa, indicating an asymmetry in the surface pressure field due to the tilted advection of the vortex by ambient wind. A vortex area fraction of 0.07% during the most active six hours of the day is deduced.

A Study of Daytime Convective Vortices and Turbulence in the Martian Planetary Boundary Layer Based on Half‐a‐Year of InSight Atmospheric Measurements and Large‐Eddy Simulations

“…A particularly clear example is provided in Figure 19. On all atmospheric measurements (pressure, wind speed, wind direction, and atmospheric temperature), quasi‐periodic variations with periods 1,500–2,000 s are observed (a similar signal is also found on the solar array data, see Lorenz et al., 2020). This is also observed in the field on Earth (Lorenz, 2012) and predicted by LES (Spiga, 2012; Spiga et al., 2018).…”

“…The topics related to PBL dynamics left out of the current study are detailed in the other papers of this issue: notable individual dust devil events (Lorenz et al., 2020), seismic signatures of vortices (Murdoch et al., in revision, Kenda et al., 2020), orbital observations of vortex tracks (Perrin et al., 2020), and aeolian science with InSight (Baker et al., 2020; Charalambous et al. in revision for this issue).…”

Constraining Martian Regolith and Vortex Parameters From Combined Seismic and Meteorological Measurements

“…For the rest of this study, for each vortex, the maximum pressure deficit of the vortex pressure profile measured during the vortex encounter (ΔP obs ), and the FWHM of the pressure profile in the time series (τ) are found using the "Ellehoj" function fit to the (filtered) pressure data. It should, however, be noted that Lorenz et al (2021) show that many vortex pressure traces measured by InSight are skewed (the attack time is longer than the decay time) implying that the surface pressure field around a vortex being advected in the wind is not strictly circularly symmetric, as we assume in this paper.…”

“…(2020) and discussed briefly in Lorenz et al. (2021) (Table 2, entry for Event # 00368). A dust devil track in the close vicinity of the InSight lander was identified in both in situ InSight Context Camera images and orbital HiRISE images.…”

“…The encounter durations are nonetheless similar to the encounter durations reported for the Phoenix Mars mission (mostly in the range of 5-15 s; Ellehoj et al, 2010), Mars Pathfinder (full durations of 15-51 s; Ferri et al, 2003), and MSL (1.4-20.3 s; . Lorenz et al (2021) present a catalog of 853 vortex events with ΔP obs ≥ 0.8 Pa, detected by InSight over sols 0-390, which may be consulted for statistical properties of a wider set of InSight vortices, although many events discussed in the present paper are not included in that catalog since they have ΔP obs less than this threshold. A histogram of all of the miss distances is provided in Figure 7b, assuming that x ≫ D. The miss distances of the encounters studied here range from 3 to 45 m. As τ and x are proportionally related (Equation 23), the filtering we apply to the data that removes the longest period events also removes the events with the largest miss distances.…”