Icarus最新文献

{"title":"Comparison of meteor shower observed by two collocated meteor radars at low latitudes","authors":"Maolin Lu ,&nbsp;Wen Yi ,&nbsp;Xianghui Xue ,&nbsp;Iain Reid ,&nbsp;Tingdi Chen ,&nbsp;Jinsong Chen ,&nbsp;Na Li","doi":"10.1016/j.icarus.2025.116610","DOIUrl":"10.1016/j.icarus.2025.116610","url":null,"abstract":"<div><div>We present results in which we compare simultaneous meteor shower observations using two meteor radars located in Kunming, China (25.6°N, 103.8°E). These are the 37.5 MHz ‘all-sky’ Kunming meteor radar (KMMR) and the 53.1 MHz Kunming Stratospheric–Tropospheric ST/Meteor radar (KMST). We first explore the Southern Delta Aquariids (SDA) meteor shower, one of the most active annual sources in the southern hemisphere, as an example, and one with ambiguous radiant. From this, we propose a new approach to determine the azimuthal angular deviation from true north for the radars and find a result of 14.7° on the KMMR and less than 1° for the KMST. These results are used to correct the receiving antenna baseline of the meteor radars. After correcting for this in the Horizontal Coordinate System of the KMMR, we find more than 2000 shower meteors originating from the radiant of Right Ascension (R.A.) =339.8° ± 2.7°, and declination (Dec.) = −16.9° ± 1.7° (J2000), and more than 1300 shower meteors from a region of R.A. = 339° ± 2.9°, Dec. = −16° ± 1.8° (J2000) from the KMST. A consistent finding between the radars was that SDA outbursts occur between UTC 1400 and 0100 with a geocentric velocity of ∼39 km/s. We then expended the period of investigation to 14 months to obtain a survey of meteor showers including the Geminids and Quadrantids. In this larger survey, 9 meteor showers were simultaneously detected by the two meteor radars, with good consistency on radiants and velocity. This demonstrates that it is possible to evaluate the angular deviation of any meteor radar in any specific period by using this new approach. We also found two previously unidentified meteor showers.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"437 ","pages":"Article 116610"},"PeriodicalIF":2.5,"publicationDate":"2025-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143855864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring the degree of clustering and diffusion of trans-Neptunian objects","authors":"Gabriele Pichierri,&nbsp;Konstantin Batygin","doi":"10.1016/j.icarus.2025.116560","DOIUrl":"10.1016/j.icarus.2025.116560","url":null,"abstract":"<div><div>The outer solar system is populated by a broad aggregate of minor bodies, which occupy orbits whose dynamical character ranges from long-term stable to rapidly diffusive. We investigate the chaotic properties of known distant trans-Neptunian objects (TNOs) by numerically integrating TNO clones and statistically analyzing their orbital diffusion. Comparing the measured diffusion with an analytical criterion yields a dynamically motivated separation into classes of stable, metastable and unstable objects. We then measure the level of clustering of the longitudes of perihelia and of the orbital poles, as functions of orbital distance and of their stability properties. Distant (meta)stable objects appear increasingly clustered in perihelion around <span><math><mrow><mi>ϖ</mi><mo>∼</mo><mn>5</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> for increasing semi-major axis, while the orbits of unstable objects are well described by two, roughly equally-populated groups of “clustered” and “anti-clustered” objects, with means around <span><math><mrow><mo>∼</mo><mn>2</mn><msup><mrow><mn>5</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> and <span><math><mrow><mo>∼</mo><mn>20</mn><msup><mrow><mn>5</mn></mrow><mrow><mo>∘</mo></mrow></msup></mrow></math></span> respectively. We further find that, compared to the solar system’s total angular momentum vector, the mean orbital poles of distant TNOs are significantly more misaligned for (meta)stable objects, while they remain roughly aligned for unstable objects. TNOs with intermediate orbital periods also appear to be misaligned with respect to the forced plane predicted by secular theory with the known planets. This gradation based on stability, if validated further by the upcoming VRO survey, necessitates a dynamical explanation.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"437 ","pages":"Article 116560"},"PeriodicalIF":2.5,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143864792","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sun Close-Encounter model of long-period comet and Meteoroid Orbit Stochastic Evolution","authors":"Stuart Pilorz ,&nbsp;Peter Jenniskens","doi":"10.1016/j.icarus.2025.116559","DOIUrl":"10.1016/j.icarus.2025.116559","url":null,"abstract":"<div><div>The dynamical evolution of long-period comets (LPCs) and their meteoroid streams is usually described with the Sun as the primary body, but over most of their orbits the Solar System barycenter (SSB) is effectively the orbital focus. Detailed numerical integrations show that the orbital elements in the barycentric reference frame are nearly constant, except within the orbit of Jupiter where the comet or meteoroid shifts to a heliocentric orbit. Here we show that this encounter can be modeled in the barycentric frame analogously to how planetary close encounters are treated in the heliocentric frame, with the comet captured into an elliptic orbit about the Sun as it in turn orbits SSB. Modeling the encounters as a two-body interaction in the SSB frame gives a different insight into the dynamics than offered by secular perturbation analyses, and reveals that a large portion of the stochasticity seen in the evolution of the comet’s orbit is due to the Sun’s state relative to SSB at the time of encounter. LPCs sample the Sun’s state randomly at each return, so that a statistical characterization of Sun’s state is sufficient to determine the qualitative evolution of their orbits, including stream dispersion. The barycentric orbital elements are shown to execute random walks well-characterized by Maxwellian distributions. This is superimposed atop a systematic orbital precession induced by planetary torques. Planetary close encounters add a second stochastic component, but this component does not typically dominate the solar perturbations. Based on the statistics of Sun’s state alone, the age of a long-period comet meteoroid stream in a given orbit can be derived to reasonable precision from the observed random dispersion of the angular orbital elements at Earth.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"437 ","pages":"Article 116559"},"PeriodicalIF":2.5,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143850151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Layered remnant deposits in Hellas Planitia, Mars as the remains of ancient ice mounds","authors":"Eva Z. Petrini ,&nbsp;Michael M. Sori","doi":"10.1016/j.icarus.2025.116604","DOIUrl":"10.1016/j.icarus.2025.116604","url":null,"abstract":"<div><div>Hellas Planitia is the site of many icy features in craters whose formation mechanisms offer insights into the climate processes of Mars. Layered remnant deposits (LRD) appear as crater deposits with distinct layers and have an unclear formation because of their frequent existence in the southern half of craters. We create an inventory of LRDs within Hellas Planitia using Thermal Emission Imaging System (THEMIS), Context Camera (CTX), and HiRISE images when available to measure key characteristics of LRDs and their host crater. We find 245 LRDs. Based on trends in our inventory, we propose LRDs result from old, crater-filling ice mounds that had preferential sublimation on the northern side leaving the present-day remnant in the southern portion of the crater. Understanding the formation of LRDs provides valuable insights into the broader narrative of Mars' climatic history, offering clues about past environmental conditions in the planet's Amazonian era.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"436 ","pages":"Article 116604"},"PeriodicalIF":2.5,"publicationDate":"2025-04-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143845056","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A Pyroxenite mantle on Mercury? Experimental insights from enstatite chondrite melting at pressures up to 5 GPa","authors":"Asmaa Boujibar ,&nbsp;Kevin Righter ,&nbsp;Emmanuel Fontaine ,&nbsp;Max Collinet ,&nbsp;Sarah Lambart ,&nbsp;Larry R. Nittler ,&nbsp;Kellye M. Pando","doi":"10.1016/j.icarus.2025.116602","DOIUrl":"10.1016/j.icarus.2025.116602","url":null,"abstract":"&lt;div&gt;&lt;div&gt;Enstatite chondrites are potential source material for the accretion of Mercury due to their reduced nature and enrichment in volatile elements. Understanding their melting properties is therefore important to better assess a scenario where Mercury formed from these chondrites. Here, we present experimental data on the partial melting of a modified EH4 Indarch enstatite chondrite, which was adjusted to have 18 % more metallic Si than SiO&lt;sub&gt;2&lt;/sub&gt; in mass, yielding an oxygen fugacity of 3.7 ± 0.6 below iron-wüstite redox buffer and 12 wt% Si in the metal. Experiments were performed from 0.5 to 5 GPa using piston cylinder and multi-anvil apparatuses. Results indicate that the stability field of enstatite expands relative to olivine. This expansion is likely due to the presence of Ca-S and Mg-S complexes in the silicate melt, which enhance SiO&lt;sub&gt;2&lt;/sub&gt; activity and promote enstatite crystallization. Silicate melts present a correlation between Ca and S concentrations, like the global patterns seen on Mercury's surface but with higher sulfur abundances. Additionally, sulfides show enrichment in Mg and Ca, up to 22 and 13 wt% respectively, the main remaining cations being Fe, Cr and Mn. These high Mg and Ca contents are observed at low temperatures and high silica content in the silicate melt, respectively. Partial melting of this reduced EH4 chondrite yields a large range of silicate melt compositions, due to the Mg- and Ca-rich sulfides which act as significant residual phases. High-pressure melts (2 to 5 GPa, 160–400 km depth in Mercury) are Mg-rich, similar to those in Mercury's high‑magnesium region (HMR), while low-pressure melts (0.5 to 1 GPa, 40–80 km depth) are Si-rich, comparable to the northern volcanic plains (NVP). Results suggest that a large fraction of Mercury's surface aligns compositionally with these melts, implying that Mercury's mantle could predominantly have a pyroxenitic composition. However, regions with differing compositions, such as aluminum-rich areas, like the Caloris basin, suggest local variability in mantle geochemistry. The HMR chemistry indicates melting at pressures up to the base of Mercury's mantle, possibly due to a large impact. Our study also explores whether the surface compositions could result from mixing processes like impact gardening or polybaric melting and magma mixing. The findings suggest that areas such as the intercrater plains and heavily cratered regions could be mixtures of melts from different pressures, ranging from 0.5 to 5 GPa, which corresponds to the crust-mantle to core-mantle boundaries. Overall, our results show that if Mercury formed from materials similar to enstatite chondrites, batch melting of its primitive pyroxenite mantle would yield magmas with compositions resembling those of most rocks observed on the surface. While the exact olivine content of the mantle remains uncertain, the residual mantle is likely enstatite-rich due to the extensive stability of enstatite","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"437 ","pages":"Article 116602"},"PeriodicalIF":2.5,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143859478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A highly resonant Neptunian region: A systematic search for two-body and three-body mean-motion resonances","authors":"Evgeny Smirnov","doi":"10.1016/j.icarus.2025.116584","DOIUrl":"10.1016/j.icarus.2025.116584","url":null,"abstract":"<div><div>In this study, a large-scale numerical investigation of resonant objects in the Neptune region is presented, focusing on both two-body and three-body mean-motion resonances (MMRs). Two separate simulations were conducted to identify resonant populations and quantify their prevalence.</div><div>In Simulation 1, two-body MMRs with Uranus and Neptune up to the resonant order <span><math><mrow><mi>q</mi><mo>≤</mo><mn>10</mn></mrow></math></span>, as well as three-body MMRs involving both planets up to the order <span><math><mrow><mi>q</mi><mo>≤</mo><mn>6</mn></mrow></math></span>, were examined. Using automated resonance classification techniques, it was found that 42.1% of objects are resonant, increasing to 58.2% when including controversial cases. This is significantly higher than the resonant fraction observed in the main asteroid belt. The results confirm that two-body MMRs with Neptune dominate, with a smaller but significant fraction of three-body resonances and two-body resonances with Uranus.</div><div>In Simulation 2, the analysis was extended to higher-order (<span><math><mrow><mi>q</mi><mo>≤</mo><mn>20</mn></mrow></math></span>) and high-integer-coefficient (<span><math><mrow><msub><mrow><mi>m</mi></mrow><mrow><mi>i</mi></mrow></msub><mo>≤</mo><mn>50</mn></mrow></math></span>) two-body resonances with Neptune, testing whether previously classified non-resonant objects might belong to higher-order MMRs. This second simulation revealed an additional 108 resonances and 104 new confirmed resonant objects, bringing the total fraction of resonant asteroids in the region to 49.3% confirmed cases and 65.1% with controversial cases included. Many new two-body MMRs with Neptune are found. Notably, some objects were found to be trapped in multiple resonances simultaneously.</div><div>These results demonstrate that MMRs play an important role in shaping the trans-Neptunian region, with an overall resonance fraction more than three times higher than in the main asteroid belt. All objects in this region may be in fact resonant.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"436 ","pages":"Article 116584"},"PeriodicalIF":2.5,"publicationDate":"2025-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Long-distance ranging and velocity measurements by REASON on Europa Clipper","authors":"Michelle S. Park ,&nbsp;Gregor Steinbrügge ,&nbsp;Elizabeth Wig ,&nbsp;Dustin M. Schroeder ,&nbsp;Erwan Mazarico ,&nbsp;Donald D. Blankenship","doi":"10.1016/j.icarus.2025.116585","DOIUrl":"10.1016/j.icarus.2025.116585","url":null,"abstract":"<div><div>One of the objectives of the Gravity and Radio Science (G/RS) instrument on NASA’s Europa Clipper mission is to improve our knowledge of Europa’s ephemerides, to trace the moon’s thermal-orbital evolution. Here, we present a complementary methodology to use the Radar for Europa Assessment and Sounding: Ocean to Near-surface (REASON) instrument to enhance these measurements by tracking echoes from Europa at greater distances, beyond its primary role of subsurface sounding during close flybys. We investigate the possibility of occasional REASON measurements during the non-nadir phase at altitudes beyond 40,000 km to extend the ephemerides dataset. Through radar simulations of REASON’s echoes, we evaluate and demonstrate this approach by determining the maximum altitude for surface return detection, achieved by coherently processing hundreds to thousands of pulses within the signal’s round-trip time. The received signal’s power can be further enhanced by maximizing pulse length, targeting Europa’s most reflective (leading sub-Jovian) hemisphere, and summing many compressed pulses. We also explore a phase shift approach for velocity measurements, which uses existing ranging pulses. Using Europa Clipper’s most recent trajectory design, we identify flybys that align with the best working scenarios for this approach. Our performance estimates for range and velocity resolution demonstrate that this approach could obtain measurements relevant to Europa’s ephemerides. This method offers key insights into Europa’s orbital evolution and, ultimately, its long-term habitability.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"436 ","pages":"Article 116585"},"PeriodicalIF":2.5,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143834830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Climatology of transient eddies and dust storms in the southern hemisphere of Mars","authors":"David Hinson","doi":"10.1016/j.icarus.2025.116581","DOIUrl":"10.1016/j.icarus.2025.116581","url":null,"abstract":"<div><div>This paper examines the behavior of transient eddies in the southern hemisphere of Mars and illustrates how the eddies shape the annual cycle and spatial distribution of dust storms. The investigation of transient eddies is based on off-nadir measurements of brightness temperature by the Mars Climate Sounder, which are the most direct and reliable source of information about eddy activity adjacent to the surface. Basic properties of the transient eddies are determined through least-squares analysis of brightness temperatures spanning 8.6 Mars years, yielding a far more complete description of eddy activity in the southern hemisphere than was available previously. The space-time spectrum is dominated by eddies with zonal wavenumbers 1–4 and periods shorter than 5 sols. The wave-4 component is much more important than was previously recognized. An annual cycle comprising three distinct periods of eddy activity is observed each year. Shallow (in temperature) baroclinic waves are present at <span><math><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>=</mo><mn>0</mn></mrow></math></span>–<span><math><mrow><mn>75</mn><mo>°</mo></mrow></math></span> and <span><math><mrow><mn>125</mn></mrow></math></span>–<span><math><mrow><mn>200</mn><mo>°</mo></mrow></math></span>. In the intervening period, the baroclinic waves are replaced by a deep, 3.3-sol, barotropic wave that has a relatively small amplitude near the surface. The transient eddies strongly influence the annual cycle of discrete dust storms cataloged in the Mars Dust Activity Database and the Mars Dust Storm Sequence Dataset. Dust storms are rare and their net area is negligible during the barotropic phase of eddy activity (<span><math><mrow><msub><mrow><mi>L</mi></mrow><mrow><mi>s</mi></mrow></msub><mo>=</mo><mn>75</mn></mrow></math></span>–<span><math><mrow><mn>125</mn><mo>°</mo></mrow></math></span>), when the amplitude near the surface is small. Conversely, the wind stress routinely exceeds the threshold required for dust lifting during the two baroclinic phases of eddy activity, when the amplitude near the surface is much larger, resulting in a conspicuous increase in the net area of the dust storms. Dust storms occur frequently in a corridor extending from Aonia Terra to Margaritifer Terra, owing to the presence of a persistent storm track of eddy activity in the western hemisphere. The density of dust storms in this corridor varies in response to the seasonal evolution in the strength and latitude of the storm track. Further insight is gained by consolidating results from previous studies. This investigation improves our understanding of the Martian climate in the half year centered on the southern winter solstice, when the atmosphere is relatively cool and clear.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"436 ","pages":"Article 116581"},"PeriodicalIF":2.5,"publicationDate":"2025-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of observation geometry and heating on the ultra-violet to near-infrared spectra of Mercury simulant","authors":"Mireia Leon-Dasi ,&nbsp;Sebastien Besse ,&nbsp;Camille Cartier ,&nbsp;Océane Barraud ,&nbsp;Alessandro Maturilli ,&nbsp;Alain Doressoundiram ,&nbsp;Johannes Benkhoff ,&nbsp;Laurie Llado","doi":"10.1016/j.icarus.2025.116582","DOIUrl":"10.1016/j.icarus.2025.116582","url":null,"abstract":"<div><div>The temperature of Mercury varies greatly across different latitudes due to the planet’s spin/orbit resonance, leading to modifications in the surface spectral properties. The upcoming BepiColombo mission will map the surface of the planet in the UV-TIR range, providing a more comprehensive understanding of the surface alteration. However, comparing the spectral measurements between BepiColombo and the past MESSENGER mission could be challenging due to the large differences in observation geometry. Laboratory experiments with close surface analogs in viewing conditions similar to the space-based observations are necessary to understand the effect of the space environment and interpret the orbital spectral measurements. This study presents the UV-NIR spectroscopy of a Mercury simulant to understand the impact of observation geometry and temperature on the spectral properties of the planet’s surface. The simulant (a mixture of aubrites, albite, and synthetic sulfides) and its endmembers are measured under six geometries that sample the viewing conditions of both missions. The samples are measured fresh and after heating to 450 °C during three cycles. This study finds that the observation geometry modifies the reflectance spectrum of the samples differently depending on the wavelength and composition. The analog presents a darkening, reddening, and flattening with increasing phase angle in the UV-NIR domain. The heated samples present a brightening and reddening, with a deepening of absorption bands. The spectral changes associated with observation geometry and heating are stronger with increasing Mg abundance.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"436 ","pages":"Article 116582"},"PeriodicalIF":2.5,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modelling the effect of volcanic outgassing of sulphur on early Martian surface temperatures using a 3-D Global Climate Model","authors":"A.S. Braude ,&nbsp;L. Kerber ,&nbsp;F. Lefèvre ,&nbsp;A.Y. Jaziri ,&nbsp;S.S. Hamid ,&nbsp;M. Lefèvre ,&nbsp;M. Maurice ,&nbsp;E. Millour ,&nbsp;F. Forget","doi":"10.1016/j.icarus.2025.116568","DOIUrl":"10.1016/j.icarus.2025.116568","url":null,"abstract":"<div><div>Around the time of the transition from the Late Noachian to the Early Hesperian eras (<span><math><mo>∼</mo></math></span>3.6 Gya), Mars was predicted to have been both volcanically active, and have sustained a climate warm enough to melt liquid water on its surface episodically despite a faint young sun. The effect of volcanic outgassing on the climate of early Mars and its ability to raise temperatures above the melting point of water has, however, been disputed, with a major uncertainty being the timescales over which the greenhouse effect of outgassed sulphur dioxide (SO₂) and hydrogen sulphide (H₂S) can warm the atmosphere of Mars before they react to form H₂SO₄ and S₈ aerosols which act to cool the surface of Mars. We have developed the first 3-D model of the Martian sulphur cycle from source to sink that includes outgassing of SO₂, H₂S and S₂ from the surface, the formation of H₂SO₄ and S₈ through atmospheric chemistry, and the condensation and deposition of H₂SO₄ and S₈ to the surface. We simulate the effect of a single large, day-long volcanic outgassing event on global surface temperatures, identifying the magnitude and duration of any net warming and cooling as a function of outgassing magnitude, atmospheric pressure, obliquity and aerosol particle size distribution. We confirm the results of Tian et al. (2010, EPSL 295, 412-418) and find that the persistence of the warming effect of volcanically outgassed SO₂ and H₂S on the Martian atmosphere is only of the order of days to weeks for a surface pressure range of between 0.5 and 1.5 bars. Typical outgassing magnitudes result in a net cooling of the Martian surface over timescales of 3–4 years near the equator and several decades at the poles for plume neutral buoyancy heights within the troposphere. For very high magnitudes of outgassing, the rate of H₂SO₄ cloud formation slows down due to the depletion of water vapour in the atmosphere, thereby slowing down the rate of cooling and providing a buffer against atmospheric collapse.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"436 ","pages":"Article 116568"},"PeriodicalIF":2.5,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143820569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}