In situ recording of Mars soundscape

Before the Perseverance rover landing, the acoustic environment of Mars was unknown. Models predicted that: (1) atmospheric turbulence changes at centimetre scales or smaller at the point where molecular viscosity converts kinetic energy into heat(1), (2) the speed of sound varies at the surface with frequency(2,3) and (3) high-frequency waves are strongly attenuated with distance in CO2 (refs. (2-4)). However, theoretical models were uncertain because of a lack of experimental data at low pressure and the difficulty to characterize turbulence or attenuation in a closed environment. Here, using Perseverance microphone recordings, we present the first characterization of the acoustic environment on Mars and pressure fluctuations in the audible range and beyond, from 20 Hz to 50 kHz. We find that atmospheric sounds extend measurements of pressure variations down to 1,000 times smaller scales than ever observed before, showing a dissipative regime extending over five orders of magnitude in energy. Using point sources of sound (Ingenuity rotorcraft, laser-induced sparks), we highlight two distinct values for the speed of sound that are about 10 m s(-1) apart below and above 240 Hz, a unique characteristic of low-pressure CO2-dominated atmosphere. We also provide the acoustic attenuation with distance above 2 kHz, allowing us to explain the large contribution of the CO2 vibrational relaxation in the audible range. These results establish a ground truth for the modelling of acoustic processes, which is critical for studies in atmospheres such as those of Mars and Venus.Many people helped with this project in addition to the co-authors, including hardware and operation teams, and we are most grateful for their support. This project was supported in the USA by NASA’s Mars Exploration Program and in France is conducted under the authority of CNES. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). The work of A. Munguira is supported by grant PID2019-109467GB-I00 funded by MCIN/AEI/10.13039/501100011033

Implementación de API en Python para el Planetary Spectrum Generator y aplicación a las atmósferas planetarias

Castellano: La espectroscopía aplicada a la observación de las atmósferas planetarias permite obtener una gran cantidad de información acerca de las mismas. En particular, en los rangos visible e infrarrojo del espectro reflejado podemos caracterizar sus nubes y nieblas superiores, así como su distribución vertical. Por otro lado, en el espectro térmico se obtiene información directa acerca del perfil térmico de las atmósferas, a diversos niveles en función de las longitudes de onda o frecuencias empleadas. Una de las herramientas disponibles para todo ello es el Planetary Spectrum Generator (https://psg.gsfc.nasa.gov/) de NASA Goddard Space Flight Center. En este proyecto se implementa la API (Application Program Interface) en Python para poder realizar llamadas al código y a sus herramientas de inversión desde un servidor cliente. El código ha sido implementado modularmente, de modo que puede responder a diferentes condiciones de observación en las distintas atmósferas, tanto de planetas del Sistema Solar como de planetas extrasolares. Este método ha sido utilizado en el estudio de diversos escenarios para evaluar la sensibilidad y capacidades del procedimiento.Euskera: Espektroskopiaren bitartez, informazio ugari lortu daiteke planeten atmosferei buruz. Bereziki, erreflexatutako espektroaren ikusgai eta infragorri tarteak behatuz, atmosferaren konposatuen kokapen bertikala bereizi daiteke, hodei eta guzti. Bestalde, espektro termikoak atmosferaren maila bertikal ezberdinen tenperatura inferitzea ahalbidetzen du, frekuentzia tartearen arabera. Guzti hau lortzeko eskuragarri dagoen erreminta bat NASA Goddard Space Flight Center-en Planetary Spectrum Generator (PSG) da. Lan honen koska, bere API (Application Program Interface) Python-en inplementatzea izan da, bere kodeari eta inbertsio tresnei modu lokalean deitu ahal izateko. Idatzitako kodea moldakorra izan dezan blokeetan antolatu da. Era honetan atmosferetako edozein problema fisikori aurre egiteko gai da. Metodo hau fenomeno ugari ikertzeko erabili da, bere sentsibilitate eta ahalmena balioztatzeko helburuarekin.English: The spectroscopy technique applied to planetary atmospheres allows us to gain a lot of knowledge about them. In particular, focusing our studies on the visible and near IR range of the reflected spectra we are able to characterize their vertical compound profile, including the clouds and hazes present. Additionally, from the thermal spectra the vertical temperature profile can be inferred for some atmospheric levels, depending on the sounded frequencies. One of the tools that allows these analysis is the Planetary Spectrum Generator of NASA Goddard Space Flight Center. The purpose of this project is to implement its API (Application Program Interface) in a Python code to call the packages within PSG from a local server. The code has been written per modules in such a way that it is extensible for any physical scenario that takes place in the atmospheres, provided that PSG is able to fit it. This applies not only to the Solar System's atmospheres, but also to extrasolar planets. Various scenarios have been examined with this method in order to assess the sensibility and potential of the performance

Implementación de API en Python para el Planetary Spectrum Generator y aplicación a las atmósferas planetarias

Castellano: La espectroscopía aplicada a la observación de las atmósferas planetarias permite obtener una gran cantidad de información acerca de las mismas. En particular, en los rangos visible e infrarrojo del espectro reflejado podemos caracterizar sus nubes y nieblas superiores, así como su distribución vertical. Por otro lado, en el espectro térmico se obtiene información directa acerca del perfil térmico de las atmósferas, a diversos niveles en función de las longitudes de onda o frecuencias empleadas. Una de las herramientas disponibles para todo ello es el Planetary Spectrum Generator (https://psg.gsfc.nasa.gov/) de NASA Goddard Space Flight Center. En este proyecto se implementa la API (Application Program Interface) en Python para poder realizar llamadas al código y a sus herramientas de inversión desde un servidor cliente. El código ha sido implementado modularmente, de modo que puede responder a diferentes condiciones de observación en las distintas atmósferas, tanto de planetas del Sistema Solar como de planetas extrasolares. Este método ha sido utilizado en el estudio de diversos escenarios para evaluar la sensibilidad y capacidades del procedimiento.Euskera: Espektroskopiaren bitartez, informazio ugari lortu daiteke planeten atmosferei buruz. Bereziki, erreflexatutako espektroaren ikusgai eta infragorri tarteak behatuz, atmosferaren konposatuen kokapen bertikala bereizi daiteke, hodei eta guzti. Bestalde, espektro termikoak atmosferaren maila bertikal ezberdinen tenperatura inferitzea ahalbidetzen du, frekuentzia tartearen arabera. Guzti hau lortzeko eskuragarri dagoen erreminta bat NASA Goddard Space Flight Center-en Planetary Spectrum Generator (PSG) da. Lan honen koska, bere API (Application Program Interface) Python-en inplementatzea izan da, bere kodeari eta inbertsio tresnei modu lokalean deitu ahal izateko. Idatzitako kodea moldakorra izan dezan blokeetan antolatu da. Era honetan atmosferetako edozein problema fisikori aurre egiteko gai da. Metodo hau fenomeno ugari ikertzeko erabili da, bere sentsibilitate eta ahalmena balioztatzeko helburuarekin.English: The spectroscopy technique applied to planetary atmospheres allows us to gain a lot of knowledge about them. In particular, focusing our studies on the visible and near IR range of the reflected spectra we are able to characterize their vertical compound profile, including the clouds and hazes present. Additionally, from the thermal spectra the vertical temperature profile can be inferred for some atmospheric levels, depending on the sounded frequencies. One of the tools that allows these analysis is the Planetary Spectrum Generator of NASA Goddard Space Flight Center. The purpose of this project is to implement its API (Application Program Interface) in a Python code to call the packages within PSG from a local server. The code has been written per modules in such a way that it is extensible for any physical scenario that takes place in the atmospheres, provided that PSG is able to fit it. This applies not only to the Solar System's atmospheres, but also to extrasolar planets. Various scenarios have been examined with this method in order to assess the sensibility and potential of the performance

Espectroscopía visible e infrarroja de Júpiter

[ES] En este proyecto se aborda el estudio espectroscópico de la luz reflejada por la atmósfera de Júpiter en el rango visible e infrarrojo cercano del espectro. Se emplean como referencia dos medidas observacionales y con ellas se modeliza la atmósfera del planeta mediante el código de transporte radiativo PUMAS implementado en el programa PSG de NASA. De esta forma, se obtendrá una caracterización de las capas atmosféricas situadas en la estratosfera inferior y troposfera superior

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

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 combined and simultaneous, unveil the diversity of processes driving change on today's Martian surface at Jezero crater.This work has been funded by the Spanish Ministry of Economy and Competitiveness, through the projects no. ESP2014-54256-C4-1-R (also -2-R, -3-R and -4-R); Ministry of Science, Innovation and Universities, projects no. ESP2016-79612-C3-1-R (also -2-R and -3-R); Ministry of Science and Innovation/State Agency of Research (10.13039/501100011033), projects no. ESP2016-80320-C2-1-R, RTI2018-098728-B-C31 (also -C32 and -C33), RTI2018-099825-B-C31, PID2019-109467GB-I00 and PRE2020-092562; Instituto Nacional de Técnica Aeroespacial; Ministry of Science and Innovation’s Centre for the Development of Industrial Technology; Spanish State Research Agency (AEI) Project MDM-2017-0737 Unidad de Excelencia “María de Maeztu”—Centro de Astrobiología; Grupos Gobierno Vasco IT1366-19; and European Research Council Consolidator Grant no 818602. The US co-authors performed their work under sponsorship from NASA’s Mars 2020 project, from the Game Changing Development programme within the Space Technology Mission Directorate and from the Human Exploration and Operations Directorate. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). G.M. acknowledges JPL funding from USRA Contract Number 1638782. A.G.F. is supported by the European Research Council, Consolidator Grant no. 818602

Twilight Mesospheric Clouds in Jezero as Observed by MEDA Radiation and Dust Sensor (RDS)

The Mars Environmental Dynamics Analyzer instrument, on board NASA's Mars 2020 Perseverance rover, includes a number of sensors to characterize the Martian atmosphere. One of these sensors is the Radiation and Dust Sensor (RDS) that measures the solar irradiance at different wavelengths and geometries. We analyzed the RDS observations made during twilight for the period between sol 71 and 492 of the mission (Ls 39°–262°, Mars Year 36) to characterize the clouds over the Perseverance rover site. Using the ratio between the irradiance at zenith at 450 and 750 nm, we inferred that the main constituent of the detected high-altitude aerosol layers was ice from Ls = 39°–150° (cloudy period), and dust from Ls 150°–262°. A total of 161 twilights were analyzed in the cloudy period using a radiative transfer code and we found: (a) signatures of clouds/hazes in the signals in 58% of the twilights; (b) most of the clouds had altitudes between 40 and 50 km, suggesting water ice composition, and had particle sizes between 0.6 and 2 µm; (c) the cloud activity at sunrise is slightly higher that at sunset, likely due to the differences in temperature; (d) the time period with more cloud detections and with the greatest cloud opacities is during Ls 120°–150°; and (e) a notable decrease in the cloud activity around aphelion, along with lower cloud altitudes and opacities. This decrease in cloud activity indicates lower concentrations of water vapor or cloud condensation nuclei (dust) around this period in the Martian mesosphere.This work has been funded by the Spanish Ministry of Economy and Competitiveness, through the projects no. ESP2014-54256-C4-1-R (also ESP2014-54256-C4-2-R, ESP2014-54256-C4-3-R, and ESP2014-54256-C4-4-R), Spanish Ministry of Science, Innovation and Universities, projects no. ESP2016-79612-C3-1-R (also ESP2016-79612-C3-2-R and ESP2016-79612-C3-3-R), Spanish Ministry of Science and Innovation/State Agency of Research (10.13039/501100011033), projects no. PID2021-126719OB-C41, ESP2016-80320-C2-1-R, RTI2018-098728-B-C31 (also RTI2018-098728-B-C32 and RTI2018-098728-B-C33), RTI2018-099825-B-C31. RH and ASL were supported by the Spanish project PID2019-109467GB-I00 funded by MCIN/AEI/10.13039/50110001103 and by Grupos Gobierno Vasco IT1742-22. The US co-authors performed their work under sponsorship from NASA’s Mars 2020 project, from the Game Changing Development programme within the Space Technology Mission Directorate and from the Human Exploration and Operations Directorate. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). G.M. acknowledges JPL funding from USRA Contract Number 1638782. ML is supported by contract 15-712 from Arizona State University and 1607215 from Caltech-JPL. A. V-R. is supported by the Comunidad de Madrid Project S2018/NMT-4291 (TEC2SPACE-CM)

Dust Lifting Through Surface Albedo Changes at Jezero Crater, Mars

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 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.This research has been funded by the Comunidad de Madrid Project S2018/NMT-4291 (TEC2SPACE-CM), by the Spanish State Research Agency (AEI) Project MDM-2017-0737 Unidad de Excelencia “María de Maeztu”- Centro de Astrobiología (CSIC/INTA), by the Spanish Ministry of Science and Innovation (MCIN)/State Agency of Research (10.13039/501100011033) project RTI2018-098728-B-C31, and by the project PID2021-126719OB-C41, funded by MCIN/AEI/10.13039/501100011033/FEDER, UE. RH, ASL and AM were supported by Grant PID2019-109467GB-I00 funded by MCIN/AEI/10.13039/501100011033/. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). We want to thank J. Bell for processing Mastcam-Z projections showing the entire TIRS FOV and to S. Navarro and the entire team for generating the processed wind sensor data

Near Surface Atmospheric Temperatures at Jezero From Mars 2020 MEDA Measurements

The Mars Environmental Dynamics Analyzer instrument on Mars 2020 has five Atmospheric Temperature Sensors at two altitudes (0.84 and 1.45 m) plus a Thermal InfraRed Sensor that measures temperatures on the surface and at ∼40 m. We analyze the measurements from these sensors to describe the evolution of temperatures in Jezero up to mission sol 400 (solar longitude LS = 13°–203°). The diurnal thermal cycle is characterized by a daytime convective period and a nocturnal stable atmosphere with a variable thermal inversion. We find a linear relationship between the daytime temperature fluctuations and the vertical thermal gradient with temperature fluctuations that peak at noon with typical values of 2.5 K at 1.45 m. In the late afternoon (∼17:00 Local True Solar Time), the atmosphere becomes vertically isothermal with vanishing fluctuations. We observe very small seasonal changes in air temperatures during the period analyzed. This is related to small changes in solar irradiation and dust opacity. However, we find significant changes in surface temperatures that are related to the variety of thermal inertias of the terrains explored along the traverse of Perseverance. These changes strongly influence the vertical thermal gradient, breaking the nighttime thermal inversion over terrains of high thermal inertia. We explore possible detections of atmospheric tides on near-surface temperatures and we examine variations in temperatures over timescales of a few sols that could be indicative of atmospheric waves affecting near-surface temperatures. We also discuss temperatures during a regional dust storm at LS = 153°–156° that simultaneously warmed the near surface atmosphere while cooling the surface.We are very grateful to the entire Mars 2020 science operations team. We would like to thank two anonymous reviewers for comments and suggestions that helped us to improve the quality of the manuscript. A. Munguira is supported by the grant PRE2020-092562 funded by MCIN/AEI/10.13039/501100011033 and by “ESF Investing in your future.” R. Hueso and A. Sánchez-Lavega are supported by Grant PID2019-109467GB-I00 funded by MCIN/AEI/10.13039/501100011033/and by Grupos Gobierno Vasco IT1742-22. US coauthors have been funded by NASA's STMD, HEOMD, and SMD. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). B. Chide is supported by the Director's Postdoctoral Fellowship from the Los Alamos National Laboratory. M. Lemmon is supported by contract 15-712 from Arizona State University and 1607215 from Caltech-JPL. R. Lorenz was supported by JPL contract 1655893. G. Martínez acknowledges JPL funding from USRA Contract Number 1638782. A. Vicente-Retortillo is supported by the Spanish State Research Agency (AEI) Project No. MDM-2017-0737 Unidad de Excelencia “María de Maeztu”- Centro de Astrobiología (INTA-CSIC), and by the Comunidad de Madrid Project S2018/NMT-4291 (TEC2SPACE-CM). Researchers based in France acknowledge support from CNES for their work on Perseverance

Nocturnal Turbulence at Jezero Crater as Determined From MEDA Measurements and Modeling

Mars 2020 Mars Environmental Dynamics Analyzer (MEDA) instrument data acquired during half of a Martian year (Ls 13°–180°), and modeling efforts with the Mars Regional Atmospheric Modeling System (MRAMS) and the Mars Climate Database (MCD) enable the study of the seasonal evolution and variability of nocturnal atmospheric turbulence at Jezero crater. Nighttime conditions in Mars's Planetary Boundary Layer are highly stable because of strong radiative cooling that efficiently inhibits convection. However, MEDA nighttime observations of simultaneous rapid fluctuations in horizontal wind speed and air temperatures suggest the development of nighttime turbulence in Jezero crater. Mesoscale modeling with MRAMS also shows a similar pattern and enables us to investigate the origins of this turbulence and the mechanisms at play. As opposed to Gale crater, less evidence of turbulence from breaking mountain wave activity was found in Jezero during the period studied with MRAMS. On the contrary, the model suggests that nighttime turbulence at Jezero crater is explained by increasingly strong wind shear produced by the development of an atmospheric bore-like disturbance at the nocturnal inversion interface. These atmospheric bores are produced by downslope winds from the west rim undercutting a strong low-level jet aloft from ∼19:00 to 01:00 LTST and from ∼01:00 LTST to dawn when undercutting weak winds aloft. The enhanced wind shear leads to a reduction in the Richardson number and an onset of mechanical turbulence. Once the critical Richardson Number is reached (Ri ∼ <0.25), shear instabilities can mix warmer air aloft down to the surface.This research was funded by Grant RTI2018-098728-B-C31 and PN2021-PID2021-126719OB-C41 by the Spanish Ministry of Science and Innovation/State Agency of Research MCIN/AEI/10.13039/501100011033. AM, ASL, TR, and RH were supported by Grant PID2019-109467GB-I00 funded by MCIN/AEI/10.13039/501100011033/and by Grupos Gobierno Vasco IT1366-19. Part of this research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). The JPL co-authors acknowledge funding from NASA's Space Technology Mission Directorate and the Science Mission Directorate. CEN was supported by funding from the Mars 2020 mission, part of the NASA Mars Exploration Program