The Surface Energy Budget at Gale Crater During the First 2500 Sols of the Mars Science Laboratory Mission

Abstract

We use in situ environmental measurements by the Mars Science Laboratory (MSL) mission to obtain the surface energy budget (SEB) across Curiosity's traverse during the first 2500 sols of the mission. This includes values of the downwelling shortwave solar radiation, the upwelling solar radiation reflected by the surface, the downwelling longwave radiation from the atmosphere, the upwelling longwave radiation emitted by the surface, the sensible heat flux associated with turbulent motions, and the latent heat flux associated with water phase changes. We then analyze their temporal variation on different timescales and relate this to the mechanisms causing these variations. Through its Rover Environmental Monitoring Station, MSL allows for a more accurate determination of the SEB than its predecessors on Mars. Moreover, the unprecedented duration, cadence, and frequency of MSL environmental observations allow for analyses of the SEB from diurnal to interannual timescales. The results presented in this article can be used to evaluate the consistency with predictions from atmospheric numerical models, to validate aerosol radiative properties under a range of dust conditions, to understand the energy available for solar-powered missions, and to enable comparisons with measurements of the SEB by the Perseverance rover at Jezero crater.Plain Language Summary The primary energy input at the Martian surface is the solar radiation, which depends on the time of the day and season, geographical location (latitude and altitude), and atmospheric dust and gas abundances. Another energy input is the thermal atmospheric forcing, which depends on the vertical distribution of dust and water ice aerosols as well as CO 2 and H 2 O molecules. Together with the reflected solar radiation and the thermal radiation emitted by the surface, these four terms make up the net radiative forcing of the surface. In response to it, energy outputs as turbulent motions and water phase changes emerge to cool down/warm up the ground. The remaining energy is available to control the thermal environment in the surface and shallow subsurface through conduction into the soil. By using first-of-their-kind measurements from the Mars Science Laboratory mission, we calculate the energy inputs and outputs across Curiosity's traverse over the first 2500 Martian days of the mission. We then analyze their temporal variations and relate this to the mechanisms causing such variations. An accurate determination of the surface energy budget is key to preparing for the human exploration of Mars because it contributes to improvements in the predictive capabilities of numerical models.MARTÍNEZ ET AL.

The dynamic atmospheric and aeolian environment of Jezero crater, Mars

“…A possible explanation might involve greater surface dust abundance at Perseverance than at InSight. However, orbital and in situ data suggest that both InSight and Curiosity operate in regions of overall higher albedo and surface dust abundances than Perseverance (54)(55)(56). Furthermore, InSight has observed substantial net dust accumulation on its deck and solar panels since landing (57).…”

The rich meteorology of Jezero crater over the first 250 sols of Perseverance on Mars

“…1b). The MEDA-derived TI values range from 200 to 600 J•m -2 •K -1 •s -½ , as in Gale [10]. The surface albedo (Fig.…”

Using near–surface temperature data to vicariously calibrate high-resolution thermal infrared imagery and estimate physical surface properties

“…Perhaps the greatest potential for oblique high temporal resolution imagery is the use on other planetary surfaces. Rovers on Mars have already used thermal radiometers and spectrometers for remote sensing science [ 5 , 23 ]. Thermal imaging would be the next logical step.…”