Examinando por Autor "Gillier, M."

Mostrando 1 - 3 de 3

Acceso Abierto
Dust Lifting Through Surface Albedo Changes at Jezero Crater, Mars
(Advancing Earth and Space Science (AGU), 2023-03-22) Vicente Retortillo, Álvaro; Martínez, Germán M.; Lemmon, M. T.; Hueso, R.; Johnson, J. R.; Sullivan, Robert; Newman, C. E.; Sebastián, E.; Toledo, D.; Apéstigue, Víctor; Arruego, Ignacio; Munguira, A.; Sánchez Lavega, Agustín; Murdoch, N.; Gillier, M.; Stott, A.; Mora Sotomayor, L.; Bertrand, T.; Tamppari, L. K.; De la Torre Juárez, M.; Rodríguez Manfredi, J. A.; Agencia Estatal de Investigación (AEI); National Aeronautics and Space Administration (NASA); Comunidad de Madrid; Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
We identify temporal variations in surface albedo at Jezero crater using first-of-their-kind high-cadence in-situ measurements of reflected shortwave radiation during the first 350 sols of the Mars 2020 mission. Simultaneous Mars Environmental Dynamics Analyzer (MEDA) measurements of pressure, radiative fluxes, winds, and sky brightness indicate that these albedo changes are caused by dust devils under typical conditions and by a dust storm at Ls ∼ 155°. The 17% decrease in albedo caused by the dust storm is one order of magnitude larger than the most apparent changes caused during quiescent periods by dust devils. Spectral reflectance measurements from Mastcam-Z images before and after the storm indicate that the decrease in albedo is mainly caused by dust removal. The occurrence of albedo changes is affected by the intensity and proximity of the convective vortex, and the availability and mobility of small particles at the surface. The probability of observing an albedo change increases with the magnitude of the pressure drop (ΔP): changes were detected in 3.5%, 43%, and 100% of the dust devils with ΔP < 2.5 Pa, ΔP > 2.5 Pa and ΔP > 4.5 Pa, respectively. Albedo changes were associated with peak wind speeds above 15 m·s−1. We discuss dust removal estimates, the observed surface temperature changes coincident with albedo changes, and implications for solar-powered missions. These results show synergies between multiple instruments (MEDA, Mastcam-Z, Navcam, and the Supercam microphone) that improve our understanding of aeolian processes on Mars.
Acceso Abierto
The sound of a Martian dust devil
(Nature, 2022-12-13) Murdoch, N.; Stott, A. E.; Gillier, M.; Hueso, R.; Lemmon, M. T.; Martínez, Germán M.; Apéstigue, Víctor; Toledo, D.; Lorenz, R. D.; Chide, B.; Munguira, A.; Sánchez Lavega, Agustín; Vicente Retortillo, Álvaro; Newman, C. E.; Maurice, S.; De la Torre Juárez, M.; Bertrand, T.; Banfield, D.; Navarro López, Sara; Marín, M.; Torres, J.; Gómez Elvira, J.; Jacob, Xavier; Cadu, A.; Sournac, A.; Rodríguez Manfredi, J. A.; Mimoun, D.; National Aeronautics and Space Administration (NASA); Centre National D'Etudes Spatiales (CNES); NASA Jet Propulsion Laboratory (JPL); Comunidad de Madrid; Gobierno Vasco; Agencia Estatal de Investigación (AEI); Los Alamos National Laboratory; Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Dust devils (convective vortices loaded with dust) are common at the surface of Mars, particularly at Jezero crater, the landing site of the Perseverance rover. They are indicators of atmospheric turbulence and are an important lifting mechanism for the Martian dust cycle. Improving our understanding of dust lifting and atmospheric transport is key for accurate simulation of the dust cycle and for the prediction of dust storms, in addition to being important for future space exploration as grain impacts are implicated in the degradation of hardware on the surface of Mars. Here we describe the sound of a Martian dust devil as recorded by the SuperCam instrument on the Perseverance rover. The dust devil encounter was also simultaneously imaged by the Perseverance rover’s Navigation Camera and observed by several sensors in the Mars Environmental Dynamics Analyzer instrument. Combining these unique multi-sensorial data with modelling, we show that the dust devil was around 25 m large, at least 118 m tall, and passed directly over the rover travelling at approximately 5 m s−1. Acoustic signals of grain impacts recorded during the vortex encounter provide quantitative information about the number density of particles in the vortex. The sound of a Martian dust devil was inaccessible until SuperCam microphone recordings. This chance dust devil encounter demonstrates the potential of acoustic data for resolving the rapid wind structure of the Martian atmosphere and for directly quantifying wind-blown grain fluxes on Mars.
Acceso Abierto
Vortices and Dust Devils on Jezero Crater, Mars: inner thermal structure and dependence on surface properties
(EGU General Assembly, 2024-05-16) Hueso, R.; Munguira, A.; Newman, C. E.; Martínez, Germán M.; Sánchez Lavega, Agustín; Del Río Gaztelurrutia, T.; Toledo, D.; Apéstigue, Víctor; Arruego, Ignacio; Pla García, J.; Lemmon, M. T.; Lorenz, Ralph; Vicente Retortillo, Álvaro; Navarro López, Sara; Stott, Alexander; Murdoch, N.; Gillier, M.; De la Torre Juárez, M.; Rodríguez Manfredi, J. A.