Convergent crater circulations on Mars: Influence on the surface pressure cycle and the depth of the convective boundary layer

Abstract

Modeling of slope flow circulations in idealized axisymmetric craters is used to understand (1) the large surface pressure amplitude observed in Gale Crater by the Rover Environmental Monitoring Station and (2) the shallow convective boundary layer (CBL) suggested by Curiosity imagery. Air temperatures vary within craters with greater amplitudes than outside them, becoming warmer/colder during day/night. This crater circulation effect is most significant over the depth of the crater (key parameter). Within the idealized craters, a surface pressure cycle develops (in the real atmosphere it is enhanced). Partially caused by thermal expansion, a "surge" of mass away from the craters develops during daytime. Over crater floors, the CBL depth is inhibited by a capping inversion from the adiabatic warming of widespread daytime subsidence. For a variety of craters (radius, depth, and with or without a central mound), the results are very similar. In real-atmosphere simulations over canyons or large basins, similar circulations are seen.

MarsWRF Convective Vortex and Dust Devil Predictions for Gale Crater Over 3 Mars Years and Comparison With MSL‐REMS Observations

“…Boundary layer depth is more often presented in height coordinates (bottom row of Figure ), which displays a very similar pattern. Interestingly, this is almost the reverse of the spatial distribution noted in, e.g., Tyler and Barnes (), which focused on an earlier season: Ls~150°, the time of MSL's landing. While some observations have shown that PBL depth on Mars is larger where the pressure is lower, such as over high topography (e.g., Hinson et al, , ), the nature of the southern summer circulation at Gale Crater produces an inversion of this result.…”

“…Unlike prior landing sites where dust devils have been studied, the Gale Crater site of the MSL mission has significant mesoscale topographic relief. While direct observations of circulation are limited to the MSL instruments, the nature of the circulation has been modeled by several different groups (Tyler & Barnes, , ; Rafkin et al, ; Pla‐Garcia et al, ; Newman et al, ; Fonseca et al, ; Richardson & Newman, ). The strong relief generates complex mesoscale circulations that interact both with the large‐scale flows commonly observed at other landing sites and with the microscale (PBL) circulation and structure.…”

The Modern Near-Surface Martian Climate: A Review of In-situ Meteorological Data from Viking to Curiosity

“…However, the tides observed by Curiosity are much larger than those simulated by global models, even when accounting for these tidal interactions. As such, various researchers have suggested further enhancements at the Curiosity site by crater circulations Tyler and Barnes 2015), topographic variations in the zonal band (Rafkin et al 2016), and a hydrostatic adjustment flow . Figure 4 shows the diurnal evolution of surface pressure at each landing site at L s = 145°, a seasonal date at which there is an overlap in data collected by all missions included in this study (Fig.…”

Evolution of major sedimentary mounds on Mars: Buildup via anticompensational stacking modulated by climate change

“…We have already verified [Kite et al, 2013a], using the MarsWRF model [Toigo et al, 2012;Richardson et al, 2007], that the strongest winds are on the steepest slopes for a simulation of 1 year's winds at Gale crater. Here we use the Mars Regional Atmospheric Modeling System [Rafkin et al, 2001] to extend our earlier results through exploring a range of idealized topographies [Tyler and Barnes, 2015;. MRAMS is derived from the terrestrial RAMS model [Mahrer and Pielke, 1976].…”

“…Grid cells inside a canyon or crater are generally less windy than on the plateau surrounding the depression ( Figure B3). This is partly because the plateau is subject to the morning "surge" of air moving away from the canyon [Tyler and Barnes, 2015]. However, within the crater/canyon, wind stress is about 5 times greater for 15°slopes than for flat surfaces.…”