Nighttime and Early Morning Atmospheric Waves and Transient Turbulence at Jezero Crater, Mars, Observed by the Perseverance Rover

Abstract

We study atmospheric oscillations in Jezero crater, Mars, that occur at night and dawn over stable conditions of the planetary boundary layer. These atmospheric oscillations are sporadic and can have large amplitudes, resulting in important variations in the dynamic conditions of the atmosphere. We analyze simultaneous measurements of atmospheric pressure and temperature data obtained in situ by the Mars Environmental Dynamics Analyzer (MEDA) instrument onboard the Mars2020/Perseverance rover. The observations span two Martian years of data at the crater floor and in the delta. We separate the wavelike and turbulent components of the oscillations, and use spectral analysis to examine the spectral slopes associated with different types of pressure oscillations. We identify four types of atmospheric transient oscillations: gravity waves (GW), solitary wavelike pulses (SoW), a nighttime pressure dip consistent with a solitary wave of depression, and possible Kelvin-Helmholtz (K-H) waves associated with high local turbulence. We examine diurnal and seasonal trends associated with the frequency of occurrence of these events. All the oscillations are less intense and less frequent around the aphelion season. The diurnal and seasonal trends in GW and SoW are consistent with previous studies at other locations on Mars, which may support a forcing by the large-scale atmospheric circulation. Potential K-H waves were observed during periods of relatively high dust opacity and in complex terrains, suggesting an origin near the surface when compared with similar observations on Earth. These waves had periods of 3.0–11.1 min and induced high-frequency turbulence.