Mars 2020 MEDA Measurements of Near Surface Atmospheric Temperatures at Jezero

The Mars Environmental Meteorological Station (MEDA) [1] on Mars 2020 has 5 Air Temperature Sensors (ATS) located at two heights (at 1.45m at the rover's mast, and at 0.84m on the front of the rover's lower body). These sensors measure local air temperatures with a frequency of 2 Hz on different locations to minimize thermal contamination from the rover on the environment. Thermal contamination of the measurements is caused by the interaction of the local winds with the warm Radioisotope Thermoelectric Generator (RTG), heating of the Sun over some surfaces, and different activities of the Perseverance rover, including motions and heating of instruments. However, the ensemble of ATS sensors at their different locations secures in most cases a precise determination of air temperatures.

The interpretation of the data and identification of thermal contamination events is done by examining simultaneous measurements of winds obtained with MEDA's wind sensors, available in many observation sessions, and by comparing the data with simultaneous temperature measurements obtained by MEDA's Thermal and InfraRed Sensors (TIRS) above and below the levels sampled by ATS. We also compare ATS measurements with temperature measurements from previous missions and with simple models of RTG plumes.

We show MEDA ATS temperatures over selected sols including examples of events of thermal contamination and how these events can be identified and separated from the data. We show the daily cycle of temperatures at Jezero and an analysis of its seasonal evolution over the first months of the mission together with a comparison of ATS data with model predictions of atmospheric temperatures at Jezero [2-3]. We also examine data of the ATS sensors at the two different elevations over the ground and we uncover the near surface vertical gradient of temperature in those cases where simultaneous wind sensor data indicates clean measurements at both levels.

References

[1] Rodriguez-Manfredi et al. Space Sci. Rev. (2021)

[2] Newman et al. Space Sci. Rev. (2021)

[3] Pla-Garcia et al. Space Sci. Rev. (2021)