Near Surface Atmospheric Temperatures at Jezero From Mars 2020 MEDA Measurements

Abstract

The Mars Environmental Dynamics Analyzer instrument on Mars 2020 has five Atmospheric Temperature Sensors at two altitudes (0.84 and 1.45 m) plus a Thermal InfraRed Sensor that measures temperatures on the surface and at ∼40 m. We analyze the measurements from these sensors to describe the evolution of temperatures in Jezero up to mission sol 400 (solar longitude LS = 13°–203°). The diurnal thermal cycle is characterized by a daytime convective period and a nocturnal stable atmosphere with a variable thermal inversion. We find a linear relationship between the daytime temperature fluctuations and the vertical thermal gradient with temperature fluctuations that peak at noon with typical values of 2.5 K at 1.45 m. In the late afternoon (∼17:00 Local True Solar Time), the atmosphere becomes vertically isothermal with vanishing fluctuations. We observe very small seasonal changes in air temperatures during the period analyzed. This is related to small changes in solar irradiation and dust opacity. However, we find significant changes in surface temperatures that are related to the variety of thermal inertias of the terrains explored along the traverse of Perseverance. These changes strongly influence the vertical thermal gradient, breaking the nighttime thermal inversion over terrains of high thermal inertia. We explore possible detections of atmospheric tides on near‐surface temperatures and we examine variations in temperatures over timescales of a few sols that could be indicative of atmospheric waves affecting near‐surface temperatures. We also discuss temperatures during a regional dust storm at LS = 153°–156° that simultaneously warmed the near surface atmosphere while cooling the surface.

Convective Vortices and Dust Devils Detected and Characterized by Mars 2020

“…A regional dust storm passed over Jezero from sols 312 to 318 (Ls = 153°-156°). The storm brought significant changes in atmospheric opacity (Lemmon et al, 2022), temperatures (Munguira et al, 2023), and behavior of pressure (Sánchez-Lavega et al, 2022), and also mobilized large amounts of dust and sand that caused a decrease in surface albedo. Lemmon et al (2022) present a detailed study of the dust storm.…”

“…MEDA measurements in Jezero show that variations in the values of TI over the rover's traverse correlate with strong variations in the vertical thermal gradient of the atmospheric surface layer (Munguira et al., 2023; Rodriguez‐Manfredi et al., 2023). This is the expected behavior in Mars, because terrains with low values of TI favor higher near‐noon surface temperatures and higher vertical thermal gradients, which is a key element in producing convective vortices (Rennó et al., 1998).…”

“…The Radiation and Dust Sensors (RDSs) on MEDA are a set of photodiodes oriented at different directions including a panchromatic sensor pointing to the vertical (RDS Top 7) with a 90° Field of View (Apestigue et al., 2022). In addition, MEDA measures the ground and air temperatures at different altitudes using the Thermal InfraRed Sensors (TIRSs) and Air Temperature Sensors (ATSs) packages (Munguira et al., 2023; Rodriguez‐Manfredi et al., 2021, 2023), therefore, obtaining the near surface temperature lapse rate, which is a key element in determining the frequency, intensity, horizontal size, and vertical extension of the vortices (Ordóñez‐Etxeberria et al., 2020; Rennó et al., 1998; Ryan, 1972; Spiga et al., 2021). Thus, multi‐sensorial investigations of convective vortices and DDs, and the properties of the environment in which they develop are possible with MEDA.…”

Surface Energy Fluxes and Temperatures at Jezero Crater, Mars

“…Figure 7 shows the hourly air temperatures ( T a ) for sol 143 as measured by ATS1, ATS2, ATS3, and HS at about 1.45 m height (The ATS1‐5 and HS observations are described and discussed in detail in Munguira et al. (2023) and Polkko et al. (2023)).…”

“…Figure7shows the hourly air temperatures (T a ) for sol 143 as measured by ATS1, ATS2, ATS3, and HS at about 1.45 m height (The ATS1-5 and HS observations are described and discussed in detail inMunguira et al (2023) andPolkko et al (2023)). Scatter in these observations is large during the turbulent afternoon, but together they do indicate the typical diurnal cycle of observed T s for this sol.…”