The meteo of Jezero crater as determined from MEDA observations and modeling

Understanding Martian meteorology at the surface is essential for future robotic and human exploration. The Mars 2020 Perseverance rover has provided an unprecedented opportunity to analyze the atmospheric environment of Jezero crater through its onboard weather station, MEDA (Mars Environmental Dynamics Analyzer, [1]). Prior to landing, [2] and [3] presented a set of model-based predictions for atmospheric behavior at the landing site. The purpose was to guide mission operations and serve as a baseline for post-landing model validation using real data. This study represents the fulfillment of that goal, providing a detailed comparison between in situ observations and mesoscale model predictions on Mars.

We compare MEDA observations of pressure, air and ground temperature, and horizontal wind speed and direction with MRAMS simulations at high spatial and temporal resolution. Unlike previous efforts that focused on four seasonal snapshots (solstices and equinoxes), our study incorporates MRAMS simulations of full diurnal cycles every 30° of solar longitudes (Ls) across two full Martian years. This represents the highest frequency of mesoscale modeling ever conducted at high resolution (330 m horizontal grid spacing) on Mars, offering unprecedented insight into both seasonal and interannual variability.

A diurnal structure variation of the pressure throughout the year is shown both in modeling and observations. The diurnal pressure amplitude is generally well matched in the model. Pressure normalization techniques were applied to correct for model biases, leading to improved alignment with MEDA values.

The general shape of the diurnal cycle of surface temperature is similar between the two datasets. MRAMS surface properties are interpolated from TES-derived thermal inertia datasets, which lack the spatial resolution necessary to fully capture Jezero’s known heterogeneity. This limitation likely contributes to inaccuracies in the modeled diurnal temperature amplitude.

There is a good match in wind directions between MRAMS and MEDA in most cases, but MRAMS wind speeds are generally higher than those observed with MEDA, especially between 01:00 and dawn. Those wind speed differences could be so strong because the downslope winds penetrate a little bit too far into the crater for that time of sol when compared with other modeling predictions. It is also noticeable that the wind speeds are systematically very low after sunset both in MRAMS and MEDA, following the collapse of daytime convection, but then at 20:00 the wind speeds start to increase again both in modeling and observations.

This study extends the investigation of nighttime turbulence over two Martian years presented in [4], which showed that turbulence increases as the rover approaches the western rim of Jezero crater. This enhancement may be caused by wind shear originating from the passage of an atmospheric bore wave associated with downslope winds descending from the crater’s western rim.

Overall, the agreement between MEDA and MRAMS supports the use of high-resolution mesoscale modeling as a predictive and diagnostic tool for Mars surface meteorology, and justifies the use of the model results to investigate the broader meteorological environment of the Jezero crater region. These findings support ongoing efforts to refine mesoscale modeling approaches for Mars and highlight the value of MEDA in validating model outputs at unprecedented temporal resolution. The enhanced temporal frequency of simulations—combined with careful pressure normalization and detailed analysis—provides a robust validation framework. This work also highlights the need for improved surface property characterization to enhance model fidelity, particularly for thermal processes. These results are not only valuable for reconstructing the meteorological environment of Jezero crater during the Mars 2020 mission, but also for informing future landing site selection, engineering planning, and science operations in similar terrain.

References:

[1] Rodriguez-Manfredi, J. A., De la Torre Juárez, M., Alonso, A., Apéstigue, V., Arruego, I., Atienza, T., ... & MEDA team. (2021). The Mars Environmental Dynamics Analyzer, MEDA. A suite of environmental sensors for the Mars 2020 mission. Space science reviews, 217, 1-86.

[2] Pla-García, J., Rafkin, S. C., Martinez, G. M., Vicente-Retortillo, Á., Newman, C. E., Savijärvi, H., ... & Harri, A. M. (2020). Meteorological predictions for Mars 2020 Perseverance Rover landing site at Jezero crater. Space science reviews, 216(8), 148.

[3] Newman, C. E., de la Torre Juárez, M., Pla-García, J., Wilson, R. J., Lewis, S. R., Neary, L., ... & Rodriguez-Manfredi, J. A. (2021). Multi-model meteorological and aeolian predictions for Mars 2020 and the Jezero crater region. Space Science Reviews, 217, 1-68.

[4] Pla‐García, J., Munguira, A., Rafkin, S., Newman, C., Bertrand, T., Martínez, G., ... & Rodríguez‐Manfredi, J. A. (2023). Nocturnal turbulence at Jezero crater as determined from MEDA measurements and modeling. Journal of Geophysical Research: Planets, 128(8), e2022JE007607