Examinando por Autor "Rafkin, S. C. R."

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Day-night differences in Mars methane suggest nighttime containment at Gale crater
(EDP Sciences, 2021-06-29) Webster, C. R.; Mahaffy, Paul R.; Pla García, J.; Rafkin, S. C. R.; Moores, J. E.; Atreya, S. K.; Flesch, G. J.; Malespin, C. A.; Teinturier, S. M.; Kalucha, H.; Smith, C. L.; Viúdez Moreiras, Daniel; Vasavada, A. R.; Agencia Estatal de Investigación (AEI)
We report new measurements of atmospheric methane by the Curiosity rover’s Tunable Laser Spectrometer that is part of the Sample Analysis at Mars suite (TLS-SAM), finding nondetections during two daytime measurements of average value 0.05 ± 0.22 ppbv (95% confidence interval CI). These are in marked contrast with nighttime background levels of 0.52 ± 0.10 (95% CI) from four measurements taken during the same season of northern summer. This large day-night difference suggests that methane accumulates while contained near the surface at night, but drops below TLS-SAM detection limits during the day, consistent with the daytime nondetection by instruments on board the ExoMars Trace Gas Orbiter. With no evidence for methane production by the rover itself, we propose that the source is one of planetary micro-seepage. Dynamical modeling indicates that such methane release is contained within the collapsed planetary boundary layer (PBL) at night due to a combination of nocturnal inversion and convergent downslope flow winds that confine the methane inside the crater close to the point where it is released. The methane abundance is then diluted during the day through increased vertical mixing associated with a higher altitude PBL and divergent upslope flow that advects methane out of the crater region. We also report detection of a large spike of methane in June 2019 with a mean in situ value over a two-hour ingest of 20.5 ± 4 ppbv (95% CI). If near-surface production is occurring widely across Mars, it must be accompanied by a fast methane destruction or sequestration mechanism, or both.
Acceso Abierto
Meteorological Predictions for Mars 2020 Perseverance Rover Landing Site at Jezero Crater
(Springer Link, 2020-12-14) Pla García, J.; Rafkin, S. C. R.; Martinez, G. M.; Vicente Retortillo, Á.; Newman, C. E.; Rodríguez Manfredi, J. A.; Gómez, F.; Molina, A.; Viúdez Moreiras, Daniel; Harri, Ari-Matti; Agencia Estatal de Investigación (AEI); Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
The Mars Regional Atmospheric Modeling System (MRAMS) and a nested simulation of the Mars Weather Research and Forecasting model (MarsWRF) are used to predict the local meteorological conditions at the Mars 2020 Perseverance rover landing site inside Jezero crater (Mars). These predictions are complemented with the COmplutense and MIchigan MArs Radiative Transfer model (COMIMART) and with the local Single Column Model (SCM) to further refine predictions of radiative forcing and the water cycle respectively. The primary objective is to facilitate interpretation of the meteorological measurements to be obtained by the Mars Environmental Dynamics Analyzer (MEDA) aboard the rover, but also to provide predictions of the meteorological phenomena and seasonal changes that might impact operations, from both a risk perspective and from the perspective of being better prepared to make certain measurements. A full diurnal cycle at four different seasons (L-s 0 degrees, 90 degrees, 180 degrees, and 270 degrees) is investigated. Air and ground temperatures, pressure, wind speed and direction, surface radiative fluxes and moisture data are modeled. The good agreement between observations and modeling in prior works [Pla-Garcia et al. in Icarus 280:103-113, 2016; Newman et al. in Icarus 291:203-231, 2017; Vicente-Retortillo et al. in Sci. Rep. 8(1):1-8, 2018; Savijarvi et al. in Icarus, 2020] provides confidence in utilizing these models results to predict the meteorological environment at Mars 2020 Perseverance rover landing site inside Jezero crater. The data returned by MEDA will determine the extent to which this confidence was justified.
Acceso Abierto
The diverse meteorology of Jezero crater over the first 250 sols of Perseverance on Mars
(Nature Publishing Group, 2023-01-09) Rodríguez Manfredi, J. A.; De la Torre Juárez, M.; Sánchez Lavega, Agustín; Hueso, R.; Martínez, Germán; Lemmon, M. T.; Newman, C. E.; Munguira, A.; Hieta, M.; Tamppari, L. K.; Polkko, J.; Toledo, D.; Sebastian, D.; Smith, M. D.; Jaakonaho, I.; Genzer, M.; Vicente Retortillo, Á.; Viúdez Moreiras, Daniel; Ramos, M.; Saiz López, A.; Lepinette, A.; Wolff, M.; Sullivan, R. J.; Gómez Elvira, J.; Conrad, P.; Del Río Gaztelurrutia, T.; Murdoch, N.; Arruego, I.; Banfield, D.; Boland, J.; Brown, Adrian Jon; Ceballos, J.; Domínguez Pumar, M.; Espejo, S.; Fairén, A.; Ferrándiz Guibelalde, Ricardo; Fischer, E.; García Villadangos, M.; Giménez Torregrosa, S.; Gómez Gómez, F.; Guzewich, S. D.; Harri, Ari-Matti; Jiménez Martín, Juan José; Jiménez, V.; Makinen, Terhi; Marín Jiménez, M.; Martín Rubio, C.; Martín Soler, J.; Molina, A.; Mora Sotomayor, L.; Navarro, Sara; Peinado, V.; Pérez Grande, I.; Pla García, J.; Postigo, M.; Prieto Ballesteros, O.; Rafkin, S. C. R.; Richardson, M. I.; Romeral, J.; Savijärv, H.; Schofield, J. T.; Torres, J.; Urquí, R.; Apéstigue, Víctor; Zurita, S.; Romero Guzman, Catalina; NASA Jet Propulsion Laboratory (JPL); National Aeronautics and Space Administration (NASA); Instituto Nacional de Técnica Aeroespacial (INTA); European Commission (EC); Ministerio de Economía y Competitividad (MINECO); Agencia Estatal de Investigación (AEI); California Institute of Technology (CIT); Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
NASA’s Perseverance rover’s Mars Environmental Dynamics Analyzer is collecting data at Jezero crater, characterizing the physical processes in the lowest layer of the Martian atmosphere. Here we present measurements from the instrument’s first 250 sols of operation, revealing a spatially and temporally variable meteorology at Jezero. We find that temperature measurements at four heights capture the response of the atmospheric surface layer to multiple phenomena. We observe the transition from a stable night-time thermal inversion to a daytime, highly turbulent convective regime, with large vertical thermal gradients. Measurement of multiple daily optical depths suggests aerosol concentrations are higher in the morning than in the afternoon. Measured wind patterns are driven mainly by local topography, with a small contribution from regional winds. Daily and seasonal variability of relative humidity shows a complex hydrologic cycle. These observations suggest that changes in some local surface properties, such as surface albedo and thermal inertia, play an influential role. On a larger scale, surface pressure measurements show typical signatures of gravity waves and baroclinic eddies in a part of the seasonal cycle previously characterized as low wave activity. These observations, both com
Acceso Abierto
The Mars Environmental Dynamics Analyzer, MEDA. A Suite of Environmental Sensors for the Mars 2020 Mission
(Springer Link, 2021-04-13) Rodríguez Manfredi, J. A.; De la Torre Juárez, M.; Alonso, A.; Arruego, I.; Atienza, T.; Banfield, D.; Boland, J.; Carrera, M. A.; Castañer, L.; Ceballos, J.; Chen Chen, H.; Cobos, A.; Conrad, Pamela G.; Cordoba, E.; Del Río Gaztelurrutia, T.; Vicente Retortillo, Á.; Domínguez Pumar, M.; Espejo, S.; Fairén, A.; Fernández Palma, A.; Ferri, F.; Fischer, E.; García Manchado, A.; García Villadangos, M.; Genzer, M.; Giménez, Á.; Gómez Elvira, J.; Gómez, F.; Guzewich, S. D.; Harri, Ari-Matti; Hernández, C. D.; Hieta, M.; Hueso, R.; Jaakonaho, I.; Jiménez, J. J.; Jiménez, V.; Larman, A.; Leiter, R.; Lepinette, A.; Lemmon, M. T.; López, G.; Madsen, N. S.; Mäkinen, T.; Marín Jiménez, M.; Martín Soler, J.; Martínez, Germán; Molina, A.; Mora Sotomayor, L.; Moreno Álvarez, J. F.; Navarro, Sara; Newman, C. E.; Ortega, C.; Parrondo, M. C.; Peinado, V.; Peña, A.; Pérez Grande, I.; Pérez Hoyos, S.; Pla García, J.; Polkko, J.; Postigo, M.; Prieto Ballesteros, O.; Rafkin, S. C. R.; Ramos, M.; Richardson, M. I.; Romeral, J.; Runyon, K. D.; Saiz López, A.; Sánchez Lavega, A.; Sard, I.; Schofield, J. T.; Sebastián, E.; Smith, M. D.; Sullivan, Robert; Tamppari, L. K.; Thompson, A. D.; Toledo, D.; Torrero, F.; Torres, J.; Urquí, R.; Velasco, T.; Viúdez Moreiras, Daniel; Zurita, S.; Apéstigue, Víctor; Ferrándiz, Ricardo; Romero Guzman, Catalina; Agencia Estatal de Investigación (AEI); European Research Council (ERC); Gobierno Vasco; Rodríguez Manfredi, J. A. [0000-0003-0461-9815]; Saiz López, A. [0000-0002-0060-1581]; Chen, H. [0000-0001-9662-0308]; Pérez Hoyos, S. [0000-0002-2587-4682]
NASA’s Mars 2020 (M2020) rover mission includes a suite of sensors to monitor current environmental conditions near the surface of Mars and to constrain bulk aerosol properties from changes in atmospheric radiation at the surface. The Mars Environmental Dynamics Analyzer (MEDA) consists of a set of meteorological sensors including wind sensor, a barometer, a relative humidity sensor, a set of 5 thermocouples to measure atmospheric temperature at ∼1.5 m and ∼0.5 m above the surface, a set of thermopiles to characterize the thermal IR brightness temperatures of the surface and the lower atmosphere. MEDA adds a radiation and dust sensor to monitor the optical atmospheric properties that can be used to infer bulk aerosol physical properties such as particle size distribution, non-sphericity, and concentration. The MEDA package and its scientific purpose are described in this document as well as how it responded to the calibration tests and how it helps prepare for the human exploration of Mars. A comparison is also presented to previous environmental monitoring payloads landed on Mars on the Viking, Pathfinder, Phoenix, MSL, and InSight spacecraft.