A systematic search of sudden pressure drops on Gale crater during two Martian years derived from MSL/REMS data

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

“…The pressure drops are also binned according to the magnitude of the detected pressure drop of each event, using four logarithmic magnitude bins that cover the range from the detection threshold of 0.6 Pa to the maximum vortex pressure drop magnitude detected over this period of just under 5.6 Pa. The results for the first 2 years are consistent with those presented in previously published work (see section ) and are also consistent with results for all 3 years obtained using a method very similar to that of Ordonez‐Exteberria et al () (see Text S1 and Figures S5 and S6).…”

“…Figure S1 shows some examples of pressure drops retained and removed during this step. In common with Kahanpää et al (), weak pressure drops appearing simultaneously with the REMS UV sensor passing into or coming out of the shadow of rover structures are removed as these events are apparently caused by the “shadow effect” of the REMS pressure sensor, first reported by Harri et al () and noted also by Ordonez‐Exteberria et al (). Nevertheless, by contrast with Kahanpää et al (), pressure drops with magnitude exceeding 0.8 Pa are retained.…”

“…After this, events with a magnitude smaller than a threshold value are discarded. In contrast to Kahanpää et al () and Ordonez‐Exteberria et al (), this study uses a threshold of 0.6 Pa instead of 0.5 Pa, the rationale being that the pressure data of MSL years 2 and 3 are sometimes noisier than those of year 1, complicating the identification of pressure drops smaller than 0.6 Pa. For completeness, the distribution of pressure drops is also found using a method very similar to that of Ordonez‐Exteberria et al () and using a threshold of 0.5 Pa. While this second method results infewer long duration, large pressure drops being discovered, the overall pattern of diurnal and seasonal variability is very similar using either method (see section ).…”

“…Steakley and Murphy (), Kahanpää et al (), and Ordonez‐Exteberria et al () have all previously examined vortex activity in Gale Crater using REMS data. In Steakley and Murphy (), the signatures of 245 convective vortices with pressure drops exceeding 0.3 Pa were found in the first 707 sols of the mission, equivalent to an average of ~1 vortex per sol after accounting for the incomplete temporal sampling of REMS measurements.…”

“…Such events appeared to be common during the second and third Martian year of the MSL mission, unlike during the first year. The second criterion enables the detection of pressure drops with durations longer than 60s, which is an advantage compared to the methods applied by Steakley and Murphy () and Ordonez‐Exteberria et al (). A visual inspection of every pressure drop is then performed to identify and remove any that do not look vortex‐like or which are “double counting” of the same vortex by the algorithm.…”