Dust, sand, and winds within an active Martian storm in Jezero crater

Abstract

However, in situ documentation of active lifting within storms has remained elusive. Over 5-11 January 2022 (L S 153°-156°), a dust storm passed over the Perseverance rover site. Peak visible optical depth was ∼2, and visibility across the crater was briefly reduced. Pressure amplitudes and temperatures responded to the storm. Winds up to 20 m s −1 rotated around the site before the wind sensor was damaged. The rover imaged 21 dust-lifting events-gusts and dust devils-in one 25-min period, and at least three events mobilized sediment near the rover. Rover tracks and drill cuttings were extensively modified, and debris was moved onto the rover deck. Migration of small ripples was seen, but there was no large-scale change in undisturbed areas. This work presents an overview of observations and initial results from the study of the storm.Plain Language Summary Mars commonly has local and regional dust storms, some of which grow into global dust storms. Until now, no lander or rover on Mars has observed the meteorology and processes within an active lifting storm center. The Perseverance rover experienced a large regional storm in Jezero crater over six sols (Martian days) in January 2022. It documented active dust lifting and winds reshaping the Martian sediment. Winds increased as the storm approached but were only directly monitored until the afternoon of the first sol, when the wind sensor failed during high winds. Winds, even after the loss of the wind sensor, were powerful enough to blow sand and lift dust around the rover. Rover imaging showed 21 dust devils and other dust lifting events near noon of the first sol. Images of the rover and terrain showed that there were several incidents of sediment mobilization immediately around the rover. Rover tracks were erased or heavily modified, cuttings from a recent drilling were removed, and sediment was deposited across the rover's deck. The changes wrought by the storm were concentrated on areas where the rover had previously modified the terrain, except for sand motion including the migration of small sand ripples.LEMMON ET AL.

Acoustics Reveals Short‐Term Air Temperature Fluctuations Near Mars' Surface

“…(2021). This event also matches with the timing of an excess grain motion between two consecutive SuperCam images of this target, confirming the strong atmospheric activity at this time (Lemmon et al., 2022). Therefore, microphone data could have caught shear‐driven gusts, as already observed on Mars by InSight (Chatain et al., 2021).…”

“…The agreement with both warm and climatology scenarii is excellent up to L s = 140°. Thereafter, the in situ data match better with the warm scenario (Figure 2a) which is concomitant with the increase of dust seen at Jezero (Lemmon et al., 2022), making this season warmer than the multi‐year averaged prediction. In fact, daytime atmospheric temperatures after L s = 130° remain even higher than the MCD predictions for the warm scenario, highlighting the strong impact of local dust lifting events occurring in Jezero on the near‐surface temperatures (Newman et al., 2022).…”

Lifting and Transport of Martian Dust by the Ingenuity Helicopter Rotor Downwash as Observed by High‐Speed Imaging From the Perseverance Rover

“…Third, dust lifting was easier (had a lower threshold) in disturbed material (such as rover tracks or earlier flight paths) than in undisturbed material. This is unsurprising and consistent with observations of more sediment motion in disturbed versus undisturbed material in a dust storm (Lemmon et al., 2022). Fourth, sand mobilization cannot explain all dust lifting.…”

“…The last process is least understood and in greatest need of investigation (Newman, Bertrand, et al., 2022). Dust lifting has been observed in both straight‐line winds and vortices (dust‐devils), which may be roughly equally important both outside dust storms (Newman, Hueso, et al., 2022) and during the onset of regional storms (Lemmon et al., 2022).…”

Winds at the Mars 2020 Landing Site: 1. Near‐Surface Wind Patterns at Jezero Crater

“…Summarizing what was observed regarding wind speeds during the onset of the storm at Jezero, mean winds were slightly greater during the storm than in pre‐storm conditions. On the other hand, vortex activity strongly increased during the storm, particularly in early stages (Lemmon et al., 2022) and provoked a higher probability of close encounters. One of these encounters at sol 313, 13:42, produced an intense wind gust reaching extreme wind speeds greater than 20 ms −1 that damaged the WS.…”