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On the Earth, with more than a century of seismology and on Mars, with the recent InSight seismic data, seismic signals generated through the coupling of the atmosphere with interior have been detected after atmospheric explosions, either due to coupling near the source or near the seismometer. Subsurface structure inversion have also been made on Mars and on the Earth from the joint recording by seismometer and pressure sensor of subsurface elastic deformation generated by atmospheric vortexes and the subsequent inversion of compliance. On the opposite, gravito-acoustic signals in the Earth atmosphere have been also detected after earthquakes and tsunamis. While no such signal has been observed on Mars, their detection seems realistic on Venus, either with infrasound sensors in the atmosphere or with ionospheric sensors in orbit.We present here a short comparative review of observations on Earth and Mars, with focus on coupling near the source due to atmospheric or surface explosion, on the detection at the station of atmospheric signal through compliance and on the subsurface inversion of compliance from atmospheric sources. We then extrapolate to Titan, for which we present synthetics illustrating how seismometer, such as those of the DragonFly mission, could also be used for detecting atmospheric infrasounds through compliance effect.We finally compare Earth and Mars in terms of seismic atmospheric-interior coupling with two other terrestrial bodies of the solar system, Venus and Titan, here again, we illustrate with synthetics the strength of atmospheric signals generated by quakes and discuss perspectives, in terms of observation strategy.&nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Aeolian activity, the movement of sand and dust by the wind, is common on Earth and has been observed on other planets [1]. Under the current climatic conditions on Mars, aeolian activity is the primary process of surface modification driven by winds, dust storms and wind vortices. Landed and orbiting cameras show that widespread aeolian activity occurs despite low measured and modelled winds, challenging Earth-based theories [2, 3]. Dust particles enter into long-term suspension forming global dust storms which drastically alter the Martian atmospheric dynamics and present hazards to robotic and human missions.Several models have been proposed on the long-standing conundrum of sediment transport on Mars, however, none of these have been verified on the planet. The outstanding question of what wind shear velocities mobilize sediments on Mars has remained elusive despite multiple spacecrafts carrying wind sensors and studying aeolian activity on finer spatial and temporal scales than can be achieved in orbit. Quantitative examination of aeolian activity under natural Martian surface conditions is imperative in validating transport models.The InSight lander has provided a unique opportunity for monitoring simultaneous coverage of aeolian activity on Mars by combining, for the first time, imaging with atmospheric, seismic and magnetic measurements. Previous studies spanned over just half of the first Martian year, from the end of northern winter to midsummer, and observed minor aeolian activity limited to sporadic grain motion and dust devil tracks [4, 5].In this study, we extend observations of aeolian activity for two Martian years, allowing us to infer the seasonal evolution at the landing site. We report a series of remarkable daytime vortex-induced events with pressure excursions up to 10 Pa, including an investigation of the burst in daytime vortices and emergence of nighttime vortices in northern autumn. Despite our observations reinforcing the quiescent aeolian surface environment at InSight, we observe further evidence and constrain timings of surface track formation, saltation, dust lifting and surface creep of coarser particles both on the surface of Mars and lander elements. Such an investigation was previously impossible due to power constraints allowing only intermittent meteorological measurements in the second year and wind-sensor saturation from energetic close vortex encounters that cause surface changes. Here, we derive estimates of vortex-induced peak wind speeds responsible for grain motion based on strong correlations from the excitation of high-frequency lander resonances sensitive to wind forcing measured continuously by the seismometers [6]. This wealth of data allows us to obtain a unique catalogue of complete wind-induced surface activity at InSight over two Martian years. Our findings provide an insight into the long-standing paradox of aeolian transportation on Mars by quantifying the environmental variables responsible for sand motion which help constrain current threshold and transport models.[1] Hayes (2018) Sci. [2] Kok et al. (2012) RPP [3] Newman et al. (2022) Auth. [4] Charalambous et al. (2021) JGR 126(6) e2020JE006538 [5] Baker et al., (2021) JGR [6] Charalambous et al. (2021) JGR 126(4) e2020JE006514.

After one year of surface operations at Jezero, the MEDA meteorological sensors have captured the signals produced by the close approach of hundreds of vortices and dust devils over different seasons and terrains. Here we update findings on the vortex and Dust Devils published in Hueso et al. (JGR: Planets, 2023). That work analyzed MEDA data from spring to early autumn identifying vortices as pressure drops and later characterizing them from the ensemble of MEDA measurements. In this updated analysis we show that, in winter, declining surface temperatures and smaller vertical gradients result in a wane of vortex activity. This decreased activity affects more the frequency of intense vortices (Δp >1.5 Pa) without showing a stiff decay in the total number of vortices (Δp>0.5 Pa). In this contribution we concentrate on the specific aspects of the thermodynamics of the vortices from temperature measurements obtained by MEDA that characterize the vertical thermal gradient at the time of the vortex passage. In addition, when vortices approach the rover closely in a favorable geometry (coming from the front of the vortex) we measure the increased temperatures inside the vortex. We also explore the increased nighttime vortex activity found on some sols, when pressure drops equivalent to those created by daytime vortices appear in the early morning before sunrise, with clusters of nighttime activity in winter and early spring.

Surgery is contributing to the climate crisis, not least in the outpatient sector. The present publication aims to identify the challenges this poses, and to provide clear, preferably evidence-based recommendations on environmental protection while simultaneously reducing costs.Narrative review with a non-systematic search and selection in PubMed/MEDLINE and grey area literature as well as expert interviews.Numerous primary articles, evidence syntheses, practical recommendations for action and checklists were identified and two experts were interviewed. Environmental issues were identified in the production and procurement, transport of people and goods, usage of materials, pharmaceuticals including anesthetic gases and energy consumption in the outpatient practice and also in disposal, recycling, and sterilization. High-quality publications do not describe a lack of knowledge on alternatives but on a lack of implementation in clinical practice. Therefore, the identified issues were classified in the 5‑R scheme (reduce, reuse, recycle, rethink, research) to present recommendations for action, which are synergetic in terms of cost reduction, patient and staff satisfaction. Furthermore, changes in regulatory frameworks are discussed.Outpatient surgery comes with relevant consumption of resources and carbon emissions. There are numerous opportunities for action that combine environmental protection with cost reduction as well as patient and staff satisfaction. Incentives, guidelines, and legal framework conditions are needed for comprehensive environmental protection in the private sector.HINTERGRUND: Auch die ambulante Chirurgie trägt zur Klimakrise bei. Die Publikation soll die Herausforderungen identifizieren und klare, möglichst evidenzbasierte Empfehlungen für Umweltschutz bei gleichzeitiger Kostenreduktion geben.Narratives Review mit nichtsystematischer umfangreicher Recherche in PubMed/MEDLINE und grauer Literatur sowie Befragung von Expert:innen.Eine Vielzahl an Primärarbeiten, Evidenzsynthesen, praktischen Handlungsempfehlungen und Checklisten konnte identifiziert und zwei Expert:innen befragt werden. Umweltprobleme wurden erkannt in Produktion und Beschaffung, Verkehr, beim Verbrauch von Material, Pharmaka und Energie sowie bei Entsorgung, Wiederverwertung und Sterilisation. Hochwertige Publikationen beschreiben nicht einen Mangel an Wissen um Alternativen, sondern an praktischer Umsetzung. Deshalb wurden die Probleme in das 5‑R-Schema („reduce“, „reuse“, „recycle“, „rethink“, „research“) eingeordnet, um Handlungsempfehlungen mit Synergieeffekten bezüglich Kostenreduktion, Patient:innen- und Mitarbeiter:innenzufriedenheit zu präsentieren. Des Weiteren werden Veränderungen der Rahmenbedingungen diskutiert.Ambulantes Operieren geht mit relevantem Ressourcenverbrauch einher. Es existieren zahlreiche Möglichkeiten, Umweltschutz mit Kostenreduktion sowie Zufriedenheit von Patient:innen und Mitarbeiter:innen zu verbinden. Für flächendeckenden Klimaschutz in der Niederlassung müssen Anreize und gesetzliche Rahmenbedingungen geschaffen werden.

Introduction: A successful mission to the ocean of an icy ocean world will require penetrating the ice shell with instrumentation robust to thermal and mechanical conditions that are significantly variable, down to depths of kilometers to 10s of km, while maintaining communication with the surface. A robust communication strategy and hardware that can provide data transmission rates adequate to achieve science and exploration objectives are critical for any future mission to access an ocean world’s subsurface. Here, we explore the potential of RF communications to provide that capability Background: The propagation of radio waves through ice is strongly dependent on both the wavelength chosen and the temperature, composition (including the nature and concentrations of any salts/other impurities), and texture of the ice. This has been the subject of extensive evaluation via interest in radar sounding of ice sheets on Earth and other planetary bodies [e.g. 1-4]. Early proposals for through-ice communication on Europa [e.g., 5,6] have advocated the use of RF relay modules and a recent NASA Compass concept study [7] discussed the use of tethers with coupled radio frequency (RF) repeater ‘pucks’. However, with the exception of analysis like that done by [6], work to determine if/how an RF communication system would operate reliably in an extreme environment like that expected at Europa or Enceladus has been lacking. We recently evaluated potential antenna designs and performance for a through-ice RF communication system in a modeled Europa-like environment and chose a dual resonant loop antenna design with a circumference-to-wavelength ratio between 0.8 and 1 [8]. Considerations for choosing an antenna and operating wavelength included: maximizing gain in the vertical direction; balancing choice of operating frequency against background noise sources (galactic and planetary) and acceptable attenuation in ice (across expected temperature range, composition, and texture); and providing sufficient bandwidth to channelize communication by frequency while yielding sufficient data rate. In addition, available volume for housing and deploying RF relay modules at Europa, based on current cryobot concept studies [5,7], was used as a constraint. Current Work: We are currently evaluating an RF module design (i.e., antenna, electronics, power source, etc.) that can function in a Europa- or Enceladus-like ice shell environment, for the anticipated lifetime of a cryobot mission. Previous RF relay module designs for cryobot architectures [5-7] have been conceptual in nature and have not adequately addressed fundamental thermo-mechanical constraints on RF module operation in an ocean world ice-shell. Primary among these are the need to operate for long durations at temperatures that range from < 80K to > 200K, under large hydrostatic pressures, and in the presence of periodic (tidal) or instantaneous (fracturing) forcing. We intend to model, build, and test a RF relay module notional design (Figure 1) to characterize its thermal and mechanical performance, under Europa- and Enceladus-like conditions. The notional design is cylindrical to maximize available volume in a cryobot and to help ensure a stable up-down antenna orientation when the module is deployed. Within the cylinder is a central core consisting of batteries, power/heating elements, electronics, and antennas. This is surrounded by insulating foam and encased in a ‘roll-cage’ outer structure. Modeling of the relay module notional design is underway and is using relevant thermo-mechanical characteristics of currently available, high-TRL components. Analysis of that modeling effort will be used to inform the manufacture of 2 RF module mock-ups for testing. The modules used in testing will be manufactured with space-qualified RF-transparent materials and adhesives and will utilize ‘flight-like’ assembly seams/joint construction techniques. One or two styles of access panel and a representative attachment area to the cryobot will also be included. Structural components of the module and the thermal insulating material will be manufactured as intended for a ‘flight-like’ build. All other internal components (e.g. power, antennas, electronics, etc.) will be represented in the manufactured modules with mock-ups that simulate their placement and thermo-mechanical characteristics within the module (e.g., mass, strength, thermal dissipation, conductivity). This choice was made to reduce the cost, complexity, and time required for the manufacturing process and because active internal components are not required to address the thermal and mechanical performance characteristics that are being tested. Figure 1. Notional design for a RF relay module concept that incorporates previous antenna design work [8] and considers thermal and mechanical needs for function in an ocean world ice shell. References: [1] Martinez et al., 2009, In International conference on GeoSensor Networks, pp. 131-137, Springer, Berlin, Heidelberg; [2] Blankenship et al., 2009, in Europa, pp. 631–654, Univ. of Ariz. Press, Tucson, Ariz; [3] Miller et al., 2012, Icarus, 220, 877-888; [4] Kasoulová et al., 2017 Journal of Geophysical Research: Planets, 122(3), 524-545 [5] Zimmerman et al., 2001; [6] Bryant, 2002, In Proceedings, IEEE Aerospace Conference (Vol. 1, pp. 1-356); [7] Oleson et al., 2019, NASA/TP—2019-220054.; [8] Lorenz et al., 2022, in prep.

Introduction: After orbiting and landing on an ocean world such as Europa or Enceladus, the next step will be to “rove”. However, rather than traveling along the surface, a cryobot probe would instead vertically traverse in order to reach the ocean and explore for signs of life. Many challenges exist for technologies to function within the harsh conditions at ocean worlds, including extreme temperatures, pressures, faulting, and the presence of potentially corrosive chemicals. Yet, these must be overcome. In order to return valuable science and engineering data, cryobot communication devices must be capable of transmitting data after deployment through ice shells of a few to 10s of km thick, and over mission lifetimes of several years. A strategy for cryobot communication that employs both optical tethers coupled with radio frequency (RF) relays has been suggested as part an ocean world cryobot mission architecture (e.g. Oleson et al., 2019). Here we present work on a NASA Concepts for Ocean worlds Life Detection Technology (COLDTech) project called Signals Through the Ice (STI) Tech for Ocean Worlds (OW), that builds on previous NASA SESAME STI work, to develop communication hardware solutions (e.g. Craft et al., 2022). Technology developments: Building on previous characterizations of optical tether robustness shear testing (Singh et al, 2022& in review; McCarthy et al., this meeting), RF relay antenna design (Lorenz et al, 2022), and modeling efforts to characterize Europa’s ice shell conditions (Walker et al., 2020), the OW STI Tech team is expanding efforts to consider conditions at Enceladus and other factors affecting cryobot communication technologies. Optical Tethers. A main hazard for tethered communication is the potential faulting activity inducing strain on the tether and causing data transmission reduction, or even severance the tether. Numerical models have been performed to simulate fault slip resulting from tidal forcing at multiple time points during one Europa tidal cycle. Calculations at multiple time points allow consideration of motion throughout the orbital cycle and evaluates the accumulation of strain on a tether crossing a fault at a range of different strikes, angles, and depths (Lien et al., 2022 & in prep). Calculations have also been performed to constrain Europa's deformation induced by tidal forcing and how it affects the thermal equilibrium state of the ice shell (Walker and Rhoden, 2022). Improving our understanding of the temperature and heat profiles within ice shells provides important estimates of the specific temperature and pressure environments both tethered and RF technologies will encounter on their journey through an ice shell. Also, a factor not yet constrained for ocean worlds is how a tether’s jacket material would potentially adhere to the ice. This ice-tether behavior would influence the resulting strain induced on the optical fibers during fault motion. Adhesion tests and design trades on candidate jacket and strength layer materials are in progress with a focus on making improvements for Europa and Enceladus temperatures, strain, and chemical conditions. Additionally, tethers are undergoing environmental chamber “soaks”, with tethers embedded in ice of different compositions for months. Material degradation and transmission performance is measured during and upon removal. RF relays. An initial RF relay thermo-mechanical design is undergoing evaluation to assess if the essential elements that must be housed and thermally insulated in an Europa or Enceladus ice shell can be kept at the necessary operational conditions. Essential components include batteries, power/heating elements, electronics, and antennas. Prototypes are being built and will undergo thermal and mechanical environmental tests (including thermal balance and rapid & cyclic loading). Summary: Development of optical tethers and RF relay devices for communication through ice on ocean worlds is underway by the OW STI Tech team. Through modeling of the extreme conditions at Europa and Enceladus, design and build of prototypes, and thermo-mechanical testing, these technologies will be robust to the environmental conditions and will therefore enable the search for extraterrestrial life in the subsurface of ocean worlds. Acknowledgments: We would like to acknowledge funding from grants 80NSSC19K0613 and 80NSSC21K0995 for this work. References: Craft et al. (2022) 53rd LPSC, Abstract #2753. Lien et al. (2022) AbSciCon, Abstract #518-05. Lorenz et al. (2022) NETS, May, 2022, Cleveland. Oleson et al. (2019) Europa Tunnelbot, NASA/TP—2019-220054. Singh et al. (2022) AbSciCon, Abstract #518-02. Walker and Rhoden (2022), PSJ, accepted. Walker et al. (2020) 51st LPSC, Abstract #2448.

Wind-dominated landscapes can be found on all Solar System bodies with atmospheres. These landscapes record the point of interaction of the atmosphere with the solid surface in a narrow region that also correlates with where field geologists interact with a planetary body. The Altiplano-Puna of Argentina is a high altitude, hyperarid landscape with young and easily eroded deposits and high wind activity. These factors make the region an exceptional analogue for Mars and other planetary regions where wind erosion is dominant, which includes portions of Titan, Venus and Pluto. Our field studies inform our understanding of how wind affects planetary surfaces. Figure 1. Yardangs of the Puna, carved into ash, surrounded by gravels. With young cinder cone. Introduction Wind erosion of planetary bodies yields a variety of landforms, including yardangs (wind-carved ridges), bedrock ridges, sastrugi (ridges formed in hardened snow), with many of these features covered or surrounded by gravels or sands (Fig. 1, ) [1, 2, 3]. These landforms are also found on Mars [4, 5], Titan [6] and Venus. The regular spacing seen in many of these wind-eroded landforms is postulated to have arisen naturally out of wind-sediment relationships possibly controlled by bedrock hardness [7] and sediment supply [8] more than pre-existing fracturing or river channels, though both of those have also been implicated [9]. Our ongoing field project in the Puna of Argentina involves field operations over 5-7 days using observations and simple instrumentation. Our methods are designed to measure the effects of current and past winds, rock properties, and erosive power of sands and gravels on yardang and bedrock ridge morphologies. We investigate the proposition that the simple action of wind on solid surfaces can lead to the complex, self-organized forms observed where wind is dominant and surfaces are erodible. The Puna Field Site and Methods The Puna desert is dominated by young deposits of volcanic ash [10], evaporites and basalt cinder cones. The high elevation means air density is lower about ~1/3 compared to sea level. On Mars, the lower air density leads to large and high dust devils, and similarly large dust devils have been observed during our field campaigns in the Puna [11]. The ash deposits are widespread, and often contain up to km-scale (mega) yardangs. The youngest and softest ignimbrite, called the Campo de Piedra Pomez (CPP) [10], contains abundant medium-sized (meter-scale), mesoyardangs. We visited this region in 2015, 2018 and 2019 (Fig. 1). Fig. 2. Smoke released near a lone yardang, revealing sideways (secondary) winds. We examined field relationships such as orientations of yardangs, rock hardness and layering. We observed differences in rock colors related to intrinsic composition as well as weathering over time. We recorded relative matrix/pumice hardnesses and subsequent variations in erosional properties. We measured locations and sizes of wind indicators such as dedos (protrusions protected by harder lithics) and scours. We observed the action of wind on a single yardang over the course of a 7-day field excursion with an array of small instruments including Kestrel anemometers, simple smoke candles and a camera (Fig. 2), and a tuft net [12]. We deployed two DJI Mavic drones across the main CPP field to obtain a 3 cm DEM (Fig. 3), which also reveals parameters such as length, orientation, and spacing. Key Observations Winds over the time we observed the lone yardang (Fig. 3) in 2019 were dominantly from a direction oblique to the yardang long axis orientation and previously observed primary winds. This secondary wind may impact yardang size and shape. Preliminary results from study of the drone DEM obtained in 2019 reveal a 1:1 width/spacing relationship, similar to other studies. This is ascribed to the steady operation of wind and erosive agents over time on a relatively uniform substrate. A similar ratio was found using a DEM for a portion of the Medusae Fossae Formation (MFF) on Mars. A dark orange coating on the leeward sides of the yardangs [13] (Figs. 2 and 3) is not presently being eroded. They are likely older surfaces reflective of the slopes of the wind-eroded surfaces at the onset of yardang emergence. Fig. 3. Drone view of CPP yardang field (DEM images obtained from higher altitude). Person for scale. Summary and Conclusions Field studies in the Puna have revealed that unique landforms emerge when wind is dominant. Regularly spaced features such as yardangs or ridges emerge out of the interaction between wind and bedrock. Sizes and spacings of features likely reflect rock hardness properties. The utility of simple, reconnaissance-style field campaigns is evident in the knowledge gained through our studies of the Puna. References [1] Blackwelder (1934), Yardangs. GSA Bulletin 45. [2] Ward (1979), Yardangs on Mars. JGR 8147-8166. [3] de Silva et al. (2013) Gravel-mantled megaripples of the Puna, GSA Bulletin 125. [4] Greeley & Iverson (1985), Threshold speeds on Venus, LPSC. [5] Kerber et al. (2011), Origin of Medusa Fossae Formation Mars, Icarus 216. [6] Paillou et al. (2016), Radar scattering of linear dunes and mega-yardangs on Titan, Icarus 270. [7] de Silva S. et al. (2010), Yardangs in terrestrial ignimbrites, PSS 58. [8] Pelletier et al. (2018), Yardang development JGR 123. [9] Dong et al. (2012), Yardangs in the Kumtaugh, Geomorphology 139. [10] Baez et al. (2020), Puna flow dynamics, Bull. Volc. 82. [11] Lorenz & Radebaugh (2016), Dust devils in thin air, GRL 43. [12] Kerber et al., in prog, Puna Yardang Observations. [13] Aulinas et al., (2015), Rock Varnish in Dusty Regions, ESP 40.

Engineering development of future Titan missions demands a specification of winds and gusts. Despite the very austere Huygens data on which to base such a specification, fundamental scaling principles allow the adaptation of empirical terrestrial descriptions for both discrete gusts and continuous turbulence. The principal factors driving these are the mean wind, the depth of the planetary boundary layer, and convective forcing : in the absence of strong mean wind, the gusts are driven by thermal vortices ('dust devils') which have a thermodynamic limit. A succinct formulation of turbulence, yielding a Dryden spectrum (-2 power law) is developed with a random-walk (AR(1)) model, that can be implemented with a few lines of code (Lorenz, R., Planetary and Space Science, 214, 105459. https://doi.org/10.1016/j.pss.2022.105459). This spectrum is nearly the same as the Von Karman/Kolmogorov (-5/3 power law). The history of turbulence specifications, and the models being developed for Dragonfly and for an update to the Titan-GRAM statistical modeling package, and their validation with in-situ data, are described.

While Mars Polar Lander and Phoenix carried microphones, InSight has recorded infrasound, and Huygens and Venera returned some acoustic measurements, Mars 2020/Perseverance is the first planetary mission to return significant amounts of human-audible acoustic data. In addition to the public appeal of planetary sound recordings, these data reveal important aspects of the Martian environment.Positioned near the top of the rover’s mast, the SuperCam microphone records audible sounds from 20 Hz to 10 kHz. A separate body-fixed microphone is associated with the EDL cameras. Detected sounds originate from three main sources: the atmosphere (turbulence, wind), the crack of the SuperCam laser blasts on rocks, and other rover sounds, such as the high-speed scroll compressor pump on the MOXIE instrument, or the aeroacoustic signal generated by the high-speed rotating blades of the Ingenuity helicopter. These sounds spread over the entire frequency domain accessible by the microphone: (i) the turbulence/wind-induced acoustic signal starts from the lowest frequency, continuously up to few hundred Hz depending on the wind activity. Acoustic power versus frequency shows a decreasing slope consistent with the dissipative regime. (ii) The frequency content of the laser-induced spark lies at higher frequencies (2 - 10 kHz) where it shows destructive interference gaps due to echoes on the mast structure. (iii) Rover generated sounds (MOXIE compressor, rover thermal pump) are monotonic. (iv) Three of the Ingenuity helicopter flights are heard, at the blade’s passing frequency of ~84Hz (with a small Doppler shift due to flight speed) and its first harmonic at 168 Hz.Passive microphone observations are now made routinely to characterize turbulence, where the observations can access timescales shorter than conventional wind sensors. Similarly, the propagation times of the crack sounds from rapid series of laser shots can interrogate temperature fluctuations on length scales smaller than is possible with conventional temperature sensing. The observations also constrain the acoustic propagation in the Martian atmosphere, where the abundant CO2 causes appreciable attenuation, especially at high frequencies. This presentation will review results to date.

NASA’s Mars 2020 Perseverance rover landed in Jezero Crater (~18.4ºN, 77.6ºE) on February 2021 at Ls~5º, just after the northern spring equinox. Perseverance carries the Mars Environmental Dynamics Analyzer (MEDA) instrument [1], which includes a wind sensor that is a heritage from previous sensors sent to Mars as part of the Mars Science Laboratory (MSL) and InSight missions. Those sensors allowed the characterization of the near-surface wind patterns at Gale Crater [2] and Elysium Planitia [3,4]. The wind sensor of MEDA is allowing near-surface wind patterns to be characterized at Perseverance’s landing site, thus complementing the data acquired by previous missions on the surface of Mars.Previous missions at different locations on the Martian surface observed a contribution by several mechanisms from different scales involved in the near-surface winds, including the effect of local and regional slope winds induced by topography, thermal tides, baroclinic waves and the Hadley cell, each one with a variable weight on the resulting wind patterns as a function of location, season and the presence of dust storms (e.g. [2-4] and references therein). The near-surface wind data acquired by Mars 2020 show a complex dynamics at Jezero Crater, as predicted by models (e.g. [5]). Preliminary interpretation suggests that the diurnal cycle of winds is dominated by the regional circulation mainly forced by slope winds in the Isidis basin region, which interact with the local scale circulation at Jezero and Hadley cell flows. The potential contribution by these mechanisms on the resulting wind patterns measured at Mars2020’s landing site will be presented, with a further focus on the observed wind variability supported by probabilistic models. References:[1] Rodriguez-Manfredi et al. (2021), SSR, 217(48). [2] Viúdez-Moreiras et al. (2019), Icarus, 319, 909-925. [3] Banfield et al. (2020), Nat.Geo, 13, 190-198. [4] Viúdez-Moreiras et al. (2020) JGR-Planets, 125, e2020JE006493. [5] Newman et al. (2021) SSR, 217(20).

International audience; The NASA InSight lander has recorded many pressure drops attributed to convective vortices during its first full year of data collection. However, although dust-carrying vortices (dust devils) are a common phenomenon on Mars, they have not been observed in InSight images. On Earth, magnetic signals associated with some dust devils have been reported. Data from the InSight Fluxgate Magnetometer (IFG) provide the first opportunity for similar investigations on Mars. Here, we evaluate whether magnetic signals are associated with daytime vortices. We incorporate observations of environmental conditions, measurements of ground tilt from seismic data, and data from the lander's solar panels, and consider the potential for dust-laden vortices to generate observable magnetic field signals. We find that 7.7% of pressure drop events greater than 1 Pa show a resolvable magnetic field signal at the time of the pressure drops. The resolvable magnetic signals, typically seen on the horizontal field components, are less than 1 nT in amplitude, and have no clear correlation with local time, duration, or pressure drop magnitude. During nine pressure drop events we found smoothly varying magnetic signals of at least 0.3 nT on any one component. To investigate the origin of these magnetic signals we evaluated three possible sources: solar array currents (SAC), ground and lander tilt, and triboelectric effects of lofted dust. We find that SAC and tilt could contribute a change in the magnetic field but cannot solely explain the observed signals. The observed changes in field strength could theoretically be produced via triboelectric effects, but only in the case of exceptionally large dust devils that pass close to the lander. The lack of imaged dust devils and the small number of observed magnetic signatures despite numerous measured pressure drops is consistent with at most a small proportion of dust laden convective vortices at InSight and associated predicted triboelectric effects.

The Deep Atmosphere Venus Investigation of Noble gases, Chemistry, and Imaging (DAVINCI) mission described herein has been selected for flight to Venus as part of the NASA Discovery Program. DAVINCI will be the first mission to Venus to incorporate science-driven flybys and an instrumented descent sphere into a unified architecture. The anticipated scientific outcome will be a new understanding of the atmosphere, surface, and evolutionary path of Venus as a possibly once-habitable planet and analog to hot terrestrial exoplanets. The primary mission design for DAVINCI as selected features a preferred launch in summer/fall 2029, two flybys in 2030, and descent sphere atmospheric entry by the end of 2031. The in situ atmospheric descent phase subsequently delivers definitive chemical and isotopic composition of the Venus atmosphere during a cloud-top to surface transect above Alpha Regio. These in situ investigations of the atmosphere and near infrared descent imaging of the surface will complement remote flyby observations of the dynamic atmosphere, cloud deck, and surface near infrared emissivity. The overall mission yield will be at least 60 Gbits (compressed) new data about the atmosphere and near surface, as well as first unique characterization of the deep atmosphere environment and chemistry, including trace gases, key stable isotopes, oxygen fugacity, constraints on local rock compositions, and topography of a tessera., Comment: 41 pages, 14 figures, accepted for publication in the Planetary Science Journal

The sounds of the Ingenuity Helicopter flying in the Martian atmosphere are among the most notable recordings of the microphone on the SuperCam instrument on the Mars 2020 Perseverance Rover. Distinct acoustic signatures of the helicopter were recorded on the 4th, 5th, 6th, and 8th flights. The detected signatures are around 84 Hz and (occasionally) at 168 Hz, at the blade crossing frequency and its first harmonic. Several higher harmonics were prominent in hover tests in short-range recordings in a test chamber on Earth; these are attenuated by CO2 absorption at the 50 m-plus ranges on Mars. Doppler shift of the 84 Hz signal can be measured and is consistent with the trajectory measured with Ingenuity’s navigation camera and inertial navigation unit, and documented by Perseverance’s cameras. A striking feature of the sound recordings is an unanticipated deep modulation of the signals with nulls spaced by around 15–20 s, superposed on the simple and expected decline in amplitude with distance. We have evaluated and rejected models of multipath sound interference as requiring implausibly strong near-surface temperature gradients. We find instead that the modulation appears to be the signature of a slight asynchrony between the rotation rates of the two coaxial rotors, such that the blade-crossing azimuth rotates slowly during flight, resulting in a “lighthouse” sweeping of the radiated sound pattern. Analysis of blade orientations seen in the shadow of the helicopter observed in down-looking navigation images supports this model.

One of the particular interest of the SuperCam microphone onboard the NASA’s Perseverance rover is that it is coupled with its own reproducible sound source, the blast waves generated by the SuperCam laser-induced plasma expansion. This unique emission-reception pair on Mars is used to investigate the propagation of spark-induced N-waves through the turbulent CO2-dominated Mars atmosphere. The analysis of waveforms shows large distortions over a burst of 30 subsequent shots, which is consistent with previous laboratory recordings of N-waves through thermal turbulence. Especially, this distortion leads to a scattering of the peak pressure amplitude, whose distribution can be fitted with a generalized gamma function. For bursts recorded farther than 4 m, the distribution gets asymmetric with a shift of the maximum toward the left of the median due to peaks amplified more than twice the median amplitude, likely due to caustics that randomly focus the acoustic wave. On the other hand, over a Martian year, the absolute peak pressure varies by ∼50% due to changes in the acoustic impedance and Rankine-Hugoniot conditions, due to the seasonal cycles of pressure and temperature at the surface of Mars.

To study Mars chemistry, SuperCam onboard the NASA Perseverance rover fires bursts of 30 laser shots at rocks. Its microphone records the shock wave generated between 2 and 15 kHz by each laser-induced plasma for distances between 2 m and 8 m, at varying local times, from strong thermal turbulence during daytime, to weaker one at dusk or dawn. In each case, the scintillation index (the normalized variance of the intensity), and travel time are calculated. Based on extensive literature on the propagation of a spherical wave through a turbulent medium, there are enough statistics to constrain the field that causes the dispersion of acoustic data. Initial results show that data are well modeled by a Gaussian field. A negative time shift, ∼0.5% at 6 m, is observed: the resulting velocity is higher than the mean speed of sound (fast path effect). The variance of arrival times leads to a 15 cm characteristic scale during daytime. Fluctuations of the scintillation index allow the strength of the turbulence field to constrained. Other turbulence models are tested, including the Kolmogorov energy-cascade which typically prevails on Earth for the inertial regime, but has been challenged several times on Mars.

On top of listening to laser shots, rover sounds and the Ingenuity rotorcraft, SuperCam’s Mars microphone has recorded over 7 hours of ambient background noise on Mars. These background recordings contain signal due to the Martian wind. Through a comparison to the meteorological data recorded by the MEDA (Mars Environmental Dynamics Analyzer), we can determine the relationships between the microphone data, the wind and the atmospheric stability. Based on these relationships, we have determined a way to estimate the wind speed using the microphone through Gaussian process regression, a machine learning technique. Owing to the sampling rate of 25 000 samples per second, the microphone data can be used to examine Mars’ atmospheric dynamics at high frequencies, as yet unexplored on Mars. We will demonstrate how the wind speed estimates from the microphone provide an assessment of turbulence at fine scales, shedding light on the dissipative regime on Mars. One particularly interesting signal recorded by the microphone was a dust devil, which had fast varying winds within the walls of its vortex and signal from dust particles hitting the rover. Combining the microphone data with information from the MEDA sensors and navigation camera (Navcam) images enabled a full parameterization of this event.

Inguinal hernia repair, according to Desarda, is a pure tissue surgical technique using external oblique fascia to reinforce the posterior wall of the inguinal canal. This has provided an impetus for the rethinking of guideline adherence toward minimally invasive and mesh-based surgery of inguinal hernia. In this study, a retrospective analysis of this technique was conducted in two German hospitals. Between 6/2013 and 12/2020, 120 operations were performed. Analysis included patient characteristics, duration of operation, length of hospital stay, and perioperative complications. Data were used to achieve a matched-pair analysis comparing Desarda to laparoscopic transabdominal preperitoneal (TAPP) hernia repair. Propensity scores were calculated based on five preoperative variables, including sex, age, American Society of Anesthesiology classification, localization, and width of the inguinal hernia in order to achieve comparability. Additionally, we assessed pain level and quality of life (QoL) 12 months postoperatively. The focus of our study was a comparison of QoL to a reference population and TAPP cohort. The study population consisted of 106 male and 14 female patients, and the median age was 37.5 years. The median operation time was 50 min, and the median length of hospital stay was 2 days. At a follow-up of 17 months, the median recurrence rate was 0.8%, and two cases of chronic postoperative pain were recorded. Postoperative QoL does not significantly differ between Desarda and TAPP. In contrast, Desarda patients had a significantly higher QoL compared with the reference population. In summary, Desarda’s procedure is a good option as a pure tissue method for inguinal hernia repair.

Titan's paleoclimate after the onset of the putative last major methane outgassing event 700 Myr ago is simulated by a global climate model. If the atmosphere was methane‐depleted prior to outgassing, outgassed methane initially causes warming due to increased greenhouse effect. Further outgassing leads to methane snowfall, which in turn cools the troposphere and surface by an ice‐albedo feedback and thereby initiates a lengthy ice age. Formation of ice sheets begins in the polar region, but with increasing methane inventory the entire globe is eventually covered by surface methane frost as thick as 100 m, with local accumulation on elevated terrains. Among various time‐dependent input parameters the methane inventory by far exerts the greatest control over the climate evolution. As Titan's climate transitions from a dry state via a partially ice‐covered state to a globally ice‐covered state, the circulation and precipitation pattern change profoundly and the tropospheric temperature further decreases. Globally ice‐covered snowball Titan is characterized by weak meridional circulation, weak seasonality and widespread snowfall. Frost ablation begins after the end of outgassing due to photochemical destruction of atmospheric methane. It is conceivable that Titan's polar seas resulted from melting of the polar caps within the past 10 Myr and subsequent drainage to the polar basins. Surface methane frost could only melt when the frost retreated to the polar region, which led to global warming by lowering of the surface albedo at low latitudes and increased greenhouse effect., Plain Language Summary: Saturn's moon Titan may have experienced long periods of cold climate in the past when the nitrogen atmosphere contained no methane unlike the present atmosphere. We simulated how Titan's climate may have changed when large amounts of methane were outgassed into such a cold atmosphere as indicated by models of Titan's evolution. The atmosphere can hold a certain amount of methane but the vast majority of outgassed methane condenses out as snow and is deposited on the surface. Bright methane snow on the surface keeps the surface cold and thereby prevents efficient greenhouse warming. Initially, surface methane frost is confined to high latitudes, but eventually the entire globe will be ice‐covered under the assumed total amount of outgassed methane. The seasonal and global pattern of atmospheric circulation and snowfall strongly depend on the degree of frost coverage. The surface frost sublimes away long after outgassing has ceased because methane is destroyed in the atmosphere by photochemistry. Eventually, the polar caps melt, leaving behind the observed polar seas., Key Points: Massive methane outgassing into Titan's atmosphere should have caused global ice sheets if the atmosphere was previously depleted in methane. Climate of methane snowball Titan is characterized by weak circulation, low temperature, weak seasonality and widespread snowfall. Melting polar caps in geologically recent past may have resulted in polar seas., Deutsche Forschungsgemeinschaft (DFG) http://dx.doi.org/10.13039/501100001659

The authors have requested that this preprint be removed from Research Square.

On 19 February 2021 the SuperCam microphone onboard Perseverance recorded the first ever sounds on the surface of Mars. These recordings of the Martian dynamic pressure fluctuations actually contain a wealth of information about the Martian atmosphere. Introduction The Mars 2020 Perseverance rover [1] landed in Jezeero crater on 18 February 2021. The SuperCam Microphone is located at a height of 2.1 m above the ground on the front of the SuperCam instrument (Fig 1; [2,3]). Although the primary science objective of the SuperCam Microphone is to support the SuperCam Laser-Induced Breakdown Spectroscopy (LIBS) investigations by providing additional information about the physical properties of the LIBS targets [4,5], the microphone also has the capacity to provide data for new and important atmospheric investigations. With a bandwidth from 100 Hz to 10 kHz, the overarching atmospheric science goal of the microphone is to characterise the Martian atmospheric dynamics at high frequency, including the diurnal and seasonal evolution. Figure 1: The SuperCam instrument, including the microphone, on the surface of Mars Studying the turbulent Martian atmosphere with the SuperCam microphone Pressure fluctuations in the atmosphere tell us about boundary layer convection, convective cells and vortices, and the inertial and dissipative regimes. Compared with Earth, Martian daytime turbulence is characterised by a stronger radiative control, a lack of latent heat forcing and a reduced inertial range [6]. Wind gustiness, convective vortex activity and the spectral slope of pressure, wind and temperature measurements can be used as indicators of turbulent motion in the atmosphere. These variables exhibit strong diurnal and seasonal variations (e.g., [7-10]). Recent analyses have also shown that wind gustiness on Mars is positively correlated to surface temperature rather than ambient wind speed and sensible heat flux [10]. Previous Martian space missions have provided valuable pressure, wind and temperature data allowing the Martian turbulence to be studied (e.g., [7,11]). The highest frequency atmospheric measurements that we currently have come from the pressure sensor on the InSight mission [12,13]. The InSight pressure measurements show unexpected behaviour. For example, they seem to contradict the theoretical predictions (Kolmogorov theory) for the cascade of the inertial range [14]. With its high sampling frequency, we can use the SuperCam microphone to study Martian turbulence on new, previously inaccessible, scales. From recordings at different local times and over different seasons, the SuperCam microphone can complement the lower frequency MEDA [15] wind speed measurements and provide a window into previously unexplored regimes of Martian atmospheric science. The SuperCam microphone as a high frequency wind sensor Pre-mission, in wind tunnel tests, it has been shown that the microphone can be used to estimate the wind speed – a quadratic relationship exists between wind speed and the microphone RMS signal [16]. However, the relationship between the microphone signal and wind speed may be more complex than this simple relationship, and other atmospheric effects (such as atmospheric stability) should also be included in the future. The dynamic pressure signal measured by the microphone is a combination of the atmospheric dynamic pressure fluctuations and the aeroacoustic fluctuations due to vortex shedding (Fig. 2; [16,17]). Simultaneous MEDA and SuperCam measurements (over 360°) are necessary in order to perform a cross-calibration activity with MEDA in order to produce absolute wind speed estimates. The microphone can also be used with single (not directional) observations to provide relative wind speed estimates, and to study the gustiness in the Martian atmosphere [18]. Figure 2: CFD simulations of vortex shedding around the SuperCam instrument under Martian atmospheric conditions with a wind speed of 5 m/s from the right of this image. The microphone is indicated by the small red sphere on the front of the instrument [16,17]. The blue and dark green areas correspond to the vortices generated around, and in the wake of, the SuperCam instrument Air temperature measurements with the SuperCam microphone Combined LIBS and SuperCam microphone operations [4, 19 - 20] can be used to probe the high frequency temperature fluctuations in the Martian atmosphere. Specifically, measuring the propagation time of the acoustic signal produced by the laser gives the sound speed from the ground to the microphone. The sound speed can then be used to derive the ‘acoustic temperature’ - the average of the air temperature over the 2 meters between the microphone and the laser target - for every laser shot (3 Hz). This is potentially important because large thermal gradients just above the Mars surface have been hinted at in previous data [21]. Conclusions The SuperCam microphone observations allow us to quantify the dynamic pressure spectra, the wind gustiness and the air temperature at high frequency thus providing an opportunity to characterise the Martian atmospheric dynamics in previously unexplored regimes. The SuperCam microphone may also be used for more opportunistic science such as searching for the acoustic signals of convective vortices [22]. References [1] Farley et al. SSR 2020. [2] Maurice et al. SSR 2021. [3] Wiens et al., SSR 2021. [4] Murdoch et al. PSS 2019. [5] Chide et al. SAB 2019. [6] Spiga et al., SSR 2019. [7] Davy et al., JGR, 2010. [8] Murdoch et al., SSR 2017. [9] Ullan et al. Icarus 2017. [10] Spiga et al. JGR-Planets 2020. [11] Larsen et al. BLM 2002. [12] Banfield et al. SSR 2019. [13] Banerdt et al. Nature Geoscience 2020. [14] Banfield, Spiga et al. Nature Geoscience 2020. [15] Rodriguez-Manfredi et al. SSR 2021. [16] Chide et al. Icarus 2021. [17] Bury et al. EPSC 2019. [18] Stott et al. EPSC 2021. [19] Chide et al. SAB 2020. [20] Chide et al. EPSC 2021. [21] Schofield et al. Science 1997. [22] Murdoch et al. LPSC 2021

The SuperCam instrument on the NASA Perseverance rover [1,2] is equipped with a microphone which, for the first time, has recorded sounds from Mars. These sounds include shockwaves from the laser-induce breakdown spectroscopy technique, the Ingenuity rotorcraft and the ambient Martian atmosphere [3,4]. Each of these offers a unique dataset to study Martian atmospheric dynamics at high frequencies. In this abstract we present preliminary results on studying the relationship between the wind and the sounds recorded from the microphone. 1. The SuperCam microphone The microphone is a Knowles Electret condenser microphone model EK-23132 [1,2,5]. It can record at sampling rates of 25kHz or 100kHz for up to 167s. The nominal bandwidth is 100Hz-10kHz but lower frequencies can be retrieved. It is located on the SuperCam mast unit 2.1m above the ground and is aligned with the camera. This means that the microphone can be made to point in different azimuths and elevations. 2. Wind speed estimation from the microphone The microphone records the atmospheric pressure at high frequencies. This dynamic pressure is linked to the winds on Mars [5,6]. In a pre-landing analogue study in a wind tunnel, Chide et al. 2021 [5] found that the root mean square (RMS) of the pressure signal is correlated to the wind speed. It was shown that the RMS value from the microphone in the bandwidth of 100-500Hz is proportional to the square of the wind speed. This frequency band was seen to not be extremely sensitive to the wind incidence azimuth but there is some uncertainty, especially for higher wind speeds. We can calculate the RMS envelope over the recording. The square root of this envelope is then proportional to wind speed and can be used as a relative estimate. Figure 1 shows initial results from an afternoon recording on Sol 38 of the mission. Figure 1: Microphone data from Sol 38. Top panel: microphone signal, Middle panel: spectrogram of microphone data, Bottom panel: square root of RMS envelope for 100-500Hz bandwidth. A cross-calibration will be performed with the Mars environmental dynamic analyser (MEDA) wind sensor [7]. This will enable us to obtain an absolute wind speed determination with the microphone. The mast will also be rotated during the cross-calibration to help capture recordings for a variety of wind speed incidence azimuths and thus also determine the sensitivity to wind direction including the identification of vortex shedding [5]. Moreover, a variation of the mast elevation may lead to the determination of vertical wind speeds. The relationship could also be sensitive to other effects, such as the atmospheric stability. To this end, we aim to track diurnal and seasonal variation, along with temperature and static pressure conditions. 3. Wind speed variation - gustiness The microphone recordings yield an estimate of the Martian wind speed. The so far obtained relative wind speed estimates can be used for an analysis of the wind gustiness, that is, the wind speed variation with respect to its mean. This has been explored for Phoenix, Viking and InSight data [6,8] with a gustiness metric defined as the wind speed standard deviation, σw, over the mean wind speed, μw, as normalised gustiness = σw/μw. The gustiness metric was applied to several microphone recordings around Noon and 16:00 local true solar time (LTST). These results indicate that the later afternoons are more turbulent than midday, where some acquisitions contain very little wind. However, the noon recordings can contain infrequent very large gusts, including the largest so far observed by the microphone. This information was utilised early on in the mission to aid the understanding of potential flight conditions for the rotorcraft Ingenuity. 4. Conclusions We have introduced how the microphone data are related to the Martian wind. It enables an estimation of the Martian wind speed and the ability to examine the high frequency content of wind gusts. This is important for the understanding of the dynamic pressure spectrum on Mars [3]. The microphone will record the high frequency portion of this dynamic pressure spectrum shedding light on the dissipative regime in Martian turbulence. The variability of the relationship to wind speed and the distribution of gustiness provides a study of high frequency Martian atmospheric dynamics, valuable for studying the Martian planetary boundary layer (PBL). References [1] Wiens et al., SSR, 2021; [2] Maurice et al., SSR, 2021; [3] Murdoch et al., EPSC, 2021 [4] Chide et al., EPSC, 2021; [5] Chide et al., ICARUS, 2021; [6] Murdoch et al., SSR, 2017; [7] Rodriguez-Manfredi et al., SSR, 2021; [8] Spiga et al., JGR, 2021

Based on an analysis of data from the Herniamed Registry, this study aims to identify all factors influencing the outcome in female groin hernia repair.In a systematic review and meta-analysis of observational studies, female sex was found to be a significant risk factor for recurrence. In the guidelines, the totally extraperitoneal patch plasty (TEP) and transabdominal preperitoneal patch plasty (TAPP) laparo-endoscopic techniques are recommended for female groin hernia repair. However, even when complying with the guidelines, a less favorable outcome must be expected than in men. To date, there is no study in the literature for analysis of all factors influencing the outcome in female groin hernia repair.In all, 15,601 female patients from the Herniamed Registry who had undergone primary unilateral groin hernia repair with the Lichtenstein, Shouldice, TEP or TAPP technique, and for whom 1-year follow-up was available, were selected between September 1, 2009 and July 1, 2017. Using multivariable analyses, influencing factors on the various outcome parameters were identified.In the multivariable analysis, a significantly higher risk of postoperative complications, complication-related reoperations, recurrences, and pain on exertion was found only for the Lichtenstein technique. No negative influence on the outcome was identified for the TEP, TAPP, or Shouldice techniques. Relevant risk factors for occurrence of perioperative complications, recurrences, and chronic pain were preoperative pain, existing risk factors, larger defects, a higher body mass index (BMI), higher American Society of Anesthesiologists (ASA) classification and postoperative complications. Higher age had a negative association with postoperative complications and positive association with pain rates.Female groin hernia repair should be performed with the TEP or TAPP laparo-endoscopic technique, or, alternatively, with the Shouldice technique, if there is no evidence of a femoral hernia. By contrast, the Lichtenstein technique has disadvantages in terms of postoperative complications, recurrences, and pain on exertion. Important risk factors for an unfavorable outcome are preoperative pain, existing risk factors, higher ASA classification, higher BMI, and postoperative complications. A higher age and larger defects have an unfavorable impact on postoperative complications and a more favorable impact on chronic pain.

On February 18, 2021, NASA’s Perseverance rover landed in Jezero Crater carrying the two first microphones operating on the surface of Mars: the SuperCam microphone, positioned on top of the rotating rover’s mast and the EDL microphone fixed on the body of the rover. Working flawlessly since then, they provide the first characterization of Mars’ acoustic environment in the audible range and beyond, from 20 Hz to 50 kHz. Recorded sounds originate from three main sources: the atmosphere (turbulence, wind), the shock-waves generated by the Supercam pulsed laser ablating rocks, and hardware-induced artificial sounds such as the signal generated by the high-speed rotating blades of the Ingenuity helicopter. After one year, the Perseverance playlist features more than 5 hours of martian sounds. In addition to providing an unprecedented short timescale characterization of the wind, temperature fluctuations, and the turbulence dissipative regime, this dataset highlights the unique sound propagation properties of the low-pressure CO2-dominated Mars atmosphere: acoustic impedance varying with the season, large intrinsic attenuation of the high frequencies, and the dispersion of the sound speed in the audible range. This presentation will review these results to date.

At first order, the physical temperature of Titan’s surface can be regarded as nearly constant and predictable. Due to the low incident solar flux reaching its surface (1/1000 of what Earth receives) and the high thermal inertia of its atmosphere, diurnal, seasonal (including latitudinal) and altitudinal variations of temperature are limited as well as the effect of surface albedo (Lorenz et al., 1999). Voyager 1 radio-occultation measurements indeed show no diurnal effect and point to lapse rates in the lower atmosphere smaller than 1.5 K/km (McKay et al 1997). Voyager infrared observations indicate a pole-to-equator temperature contrast of 2-3 K (Flasar et al., 1981; 1998).The Cassini mission (2004-2017) somewhat confirmed these predictions and first measurements. On board the Cassini spacecraft, two instruments were able to measure the physical temperature of Titan’s surface: the Cassini’s Composite IR Spectrometer (CIRS) through a spectral window of low opacity in the thermal IR and the Cassini radar used as a microwave radiometer. Both instruments monitored the surface brightness temperature at their respective wavelengths (19 microns and 2.2 cm, respectively) during the almost two Titan’s seasons of the Cassini mission. Interestingly, these two instruments probe different depths; the very surface for CIRS and at least several decimeters in the lands for the microwave radiometer (Janssen et al., 2016), much more in the lakes (Mastrogiuseppe et al., 2014). Combining these datasets thus provides insights into the vertical variations of the thermal and physical properties of the surface.From the analysis of CIRS dataset, Cottini et al. (2012) report a diurnal signal of 1-1.5 K indicative of a thermal inertia of 300-600 MKS while Jennings et al. (2009; 2016) investigate seasonal changes confirming a constant maximum temperature of 93.65 +/- 0.15 K (as measured by the Huygens probe at 10.3°S latitude, Fluchignoni et al., 2005) and a variation of the latitude at which this maximum occurs following the sub-solar latitude (which moved from 24°S to 23°N between 2004 and 2017). Jennings et al. (2016) also found a 2-4 K equator-to-pole difference and note a delay in the northern warming at the end of the mission, as summer was on its way. This later was interpreted as a cooling effect of both the lakes and the surrounding moist lands as CIRS observations show no difference in the thermal behavior of these two types of terrains (within measurement uncertainty of about 0.5 K).From the radiometry dataset, Janssen et. (2016) find latitude-dependent seasonal temperature variations smaller than those measured by CIRS by a factor of 0.87 +/- 0.05 in relative amplitude which is consistent with a penetration depth of 40 cm-1 m in organic sands. The difference with CIRS observations is slightly more pronounced in the northern hemisphere likely owing to the presence of lakes and seas in which microwaves penetrate deeper than in dry lands. In the North pole, Le Gall et al. (2016) also report the hint of a slower than expected rise in temperature in the second largest sea of Titan, Ligeia Mare, toward the end of the mission. Any diurnal effect was neglected considering that the radiometer would probe much deeper depths than the diurnal skin depth (Lorenz et al., 2003). In this work, in order to investigate further the seasonal variations of Titan’s temperature, we present the analysis of the high-resolution radiometry observations recorded in the northern pole from 2007 to 2017. This analysis demonstrates that the seas warm more slowly than their surrounding lands and are therefore responsible for the global lag in summer warming observed in Titan’s high northern latitudes both by CIRS and the Cassini radiometer. This cooling effect could be due to the high thermal inertia of liquid hydrocarbons, their high transparency (which leads microwaves to sense the coldness buried from last winter, Le Gall et al., 2016) and/or methane evaporation (Mitri et al., 2007).In addition, we present for the first time the analysis of the 118 distant observations of Titan collected during the course of the Cassini mission. These observations were designed for the computation of the disk-integrated brightness temperature of Titan. Though unresolved, they provide clues on the seasonal and longitudinal variations of Titan’s surface thermal emission. In particular, they clearly show Xanadu, a large-scale low emissivity/radar-bright feature on the leading side of the satellite. The analysis of this dataset reveals a possible diurnal component of amplitude 0.6 K and peaking at 4 pm in Titan’s radar-dark terrains and of amplitude 0.8 K and peaking at 2 pm in Xanadu. Unfortunately, such a signal cannot be isolated in high resolution observations because of the way data are calibrated (Janssen et al., 2016). If confirmed, this detection would bring a further argument for a smaller than expected electrical skin depth (i.e., a more absorptive subsurface) in most of Titan’s equatorial lands and/or a larger diurnal thermal skin depth (i.e. a higher thermal inertia), especially in Titan’s radar-dark dune terrains.To conclude, monitoring surface temperature brings key insights into the surface properties and its coupling with the atmosphere. Cassini findings provide a global context for the future observations of DraGMet, the geophysics and meteorology package on board the Dragonfly quadcopter (Lorenz et al., 2018) which will investigate the ground thermal properties and record temperature variations in parallel with the atmosphere humidity, the ground moisture and wind speed. How to cite: Le Gall, A., Bonnefoy, L., Sultana, R., Janssen, M., Lorenz, R., and Tokano, T.: Evidence of diurnal variations of Titan’s near-surface temperature and of a cooling effect of the northern seas from the Cassini radar/radiometer, Europlanet Science Congress 2020, online, 21 September–9 Oct 2020, EPSC2020-618, 2020