13 results on '"Hannes Gröller"'
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2. Escape and evolution of Mars's CO2 atmosphere: Influence of suprathermal atoms
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Fuqiang Tian, Herbert Lichtenegger, Lena Noack, Manuel Scherf, Hannes Gröller, Ute Amerstorfer, L. Tu, Helmut Lammer, Manuel Güdel, and Colin P. Johnstone
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Physics ,010504 meteorology & atmospheric sciences ,Atmosphere of Mars ,Mars Exploration Program ,01 natural sciences ,Astrobiology ,Atmosphere ,Geophysics ,Space and Planetary Science ,Geochemistry and Petrology ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
Austrian Science Fund (FWF) [P24247-N16, S11601-N16, S11604-N16, S11607-N16, S11606-N16]; Interuniversity Attraction Poles Programme
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- 2017
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3. Vertical propagation of wave perturbations in the middle atmosphere on Mars by MAVEN/IUVS
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Hitoshi Fujiwara, Takeshi Imamura, Fayu Jiang, Nao Yoshida, Nicholas M. Schneider, Kaori Terada, Naoki Terada, Kanako Seki, Sonal Jain, Loic Verdier, Justin Deighan, Hiromu Nakagawa, Hannes Gröller, Franck Montmessin, Bruce M. Jakosky, Roger V. Yelle, Scott L. England, Takeshi Kuroda, Graduate School of Information Sciences [Sendai], Tohoku University [Sendai], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Department of Aerospace and Ocean Engineering [Blackburg], Virginia Polytechnic Institute and State University [Blacksburg], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo), Faculty of Science and Technology [Tokyo], Seikei University, and Graduate School of Frontier Sciences [Kashiwa]
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Physics ,Martian ,010504 meteorology & atmospheric sciences ,Atmosphere of Mars ,Astrophysics ,Mars Exploration Program ,01 natural sciences ,Mesosphere ,Physics::Geophysics ,Atmosphere ,Geophysics ,Amplitude ,13. Climate action ,Space and Planetary Science ,Geochemistry and Petrology ,[SDU]Sciences of the Universe [physics] ,Spectral slope ,Physics::Space Physics ,Earth and Planetary Sciences (miscellaneous) ,Astrophysics::Earth and Planetary Astrophysics ,Thermosphere ,0105 earth and related environmental sciences - Abstract
International audience; This work offers the first in‐depth study of the global characteristics of wave perturbations in temperature profiles at 20 ‐ 140 km altitudes derived from the Imaging Ultraviolet Spectrograph (IUVS) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. The peak amplitudes of waves seen in temperature profiles exceed 20 % of the mean background, especially on the nightside, which is larger than those in Earth’s mesosphere and thermosphere. The wave perturbations generate an instability layer around 70‐100 km on the nightside, which potentially causes wave‐breaking and turbulences. Our results highlighted a seasonal variation in the latitudinal distribution of nightside perturbations. Amplitudes of wave perturbations were found to be large in the northern low‐latitude region and the southern polar region during the first half of the year (Ls = 0° ‐ 180°). An increase of waves in the spectral density was found in southern low‐latitude regions in the latter half of the year (Ls = 180° ‐ 360°). Vertical wavenumber spectral density in the Martian middle atmosphere shows a power‐law dependence with a logarithmic spectral slope of ‐3, similar to the features seen in the Earth’s atmosphere. The derived spectral power density suggests the longer waves growing with height while the effective dissipation of shorter waves occurs. The strong CO2 15‐micron band cooling can effectively dissipate shorter waves. In contrast, the spectral power density at longer waves suggests an amplitude growth with height of unsaturated waves up to the lower thermosphere.
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- 2020
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4. Hot oxygen and carbon escape from the martian atmosphere
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Helmut Lammer, Herbert Lichtenegger, Valery I. Shematovich, and Hannes Gröller
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Quenching ,Earth and Planetary Astrophysics (astro-ph.EP) ,Materials science ,Scattering ,Photodissociation ,chemistry.chemical_element ,FOS: Physical sciences ,Astronomy and Astrophysics ,Atmosphere of Mars ,7. Clean energy ,Oxygen ,Ion ,chemistry ,13. Climate action ,Space and Planetary Science ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,Carbon ,Dissociative recombination ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The escape of hot O and C atoms from the present martian atmosphere during low and high solar activity conditions has been studied with a Monte-Carlo model. The model includes the initial energy distribution of hot atoms, elastic, inelastic, and quenching collisions between the suprathermal atoms and the ambient cooler neutral atmosphere, and applies energy dependent total and differential cross sections for the determination of the collision probability and the scattering angles. The results yield a total loss rate of hot oxygen of $2.3-2.9\times 10^{25}\,{\rm s}^{-1}$ during low and high solar activity conditions and is mainly due to dissociative recombination of O$_2^+$ and CO$_2^+$. The total loss rates of carbon are found to be $0.8$ and $3.2\times 10^{24}\,{\rm s}^{-1}$ for low and high solar activity, respectively, with photodissociation of CO being the main source. Depending on solar activity, the obtained carbon loss rates are up to $\sim 40$ times higher than the CO$_2^+$ ion loss rate inferred from Mars Express ASPERA-3 observations. Finally, collisional effects above the exobase reduce the escape rates by about $20-30\,\%$ with respect to a collionless exophere., 8 figures and 14 tables
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- 2019
5. Solar XUV and ENA-driven water loss from early Venus' steam atmosphere
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Nikolai V. Erkaev, Kristina G. Kislyakova, Hannes Gröller, Manuel Güdel, Mats Holmström, L. Tu, Colin P. Johnstone, Linda T. Elkins-Tanton, Petra Odert, Herbert Lichtenegger, and Helmut Lammer
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Materials science ,010504 meteorology & atmospheric sciences ,Hydrogen ,chemistry.chemical_element ,Venus ,01 natural sciences ,7. Clean energy ,Atmosphere ,0103 physical sciences ,Thermal ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences ,biology ,Atmospheric escape ,biology.organism_classification ,Solar wind ,Geophysics ,chemistry ,13. Climate action ,Space and Planetary Science ,Extreme ultraviolet ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,Atomic physics ,Thermosphere - Abstract
The influence of the hydrogen hydrodynamic upper atmosphere escape, driven by the solar soft X-ray and extreme ultraviolet radiation (XUV) flux, on an expected magma ocean outgassed steam atmosphere of early Venus is studied. By assuming that the young Sun was either a weak or moderate active young G star, we estimated the water loss from a hydrogen dominated thermosphere due to the absorption of the solar XUV flux and the precipitation of solar wind produced energetic hydrogen atoms (ENAs). The production of ENAs and their interaction with the hydrodynamic extended upper atmosphere, including collision-related feedback processes, have been calculated by means of Monte Carlo models. ENAs that collide in the upper atmosphere deposit their energy and heat the surrounding gas mainly above the main XUV energy deposition layer. It is shown that precipitating ENAs modify the thermal structure of the upper atmosphere, but the enhancement of the thermal escape rates caused by these energetic hydrogen atoms is negligible. Our results also indicate that the majority of oxygen arising from dissociated H$_2$O molecules is left behind during the first 100 Myr. It is thus suggested that the main part of the remaining oxygen has been absorbed by crustal oxidation.
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- 2016
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6. MAVEN/IUVS Stellar Occultation Measurements of Mars Atmospheric Structure and Composition
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Tommi Koskinen, Justin Deighan, Nicholas M. Schneider, Roger V. Yelle, Hannes Gröller, Franck Montmessin, François Forget, Franck Lefèvre, Sonal Jain, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure - Paris (ENS-PSL), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL)
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[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,010504 meteorology & atmospheric sciences ,[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] ,Atmosphere of Mars ,Mars Exploration Program ,Atmospheric sciences ,01 natural sciences ,Occultation ,Latitude ,Atmosphere ,Geophysics ,Altitude ,13. Climate action ,Space and Planetary Science ,Geochemistry and Petrology ,0103 physical sciences ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Variation (astronomy) ,Longitude ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences - Abstract
International audience; The Imaging UltraViolet Spectrograph (IUVS) instrument of the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission has acquired data on Mars for more than one Martian year. During this time, beginning with March 2015, hundreds of stellar occultations have been observed, in 12 dedicated occultation campaigns, executed on average every two to three months. The occultations cover the latitudes from 80° S to 75° N and the full range longitude, and local times with relatively sparse sampling. From these measurements we retrieve CO2, O2, and O3 number densities as well as temperature profiles in the altitude range from 20 to 160 km, covering eight order of magnitudes in pressure from ∼2 × 101 to ∼4 × 10−7 Pa. These data constrain the composition and thermal structure of the atmosphere. The O2 mixing ratios retrieved during this study show a high variability from 1.5 × 10−3 to 6 × 10−3; however, the mean value seems to be constant with solar longitude. We detect ozone between 20 and 60 km. In many profiles there is a well defined peak between 30 and 40 km with a maximum density of 1 – 2 × 109 cm−3. Examination of the vertical temperature profiles reveals substantial disagreement with models, with observed temperatures both warmer and colder than predicted. Examination of the altitude profiles of density perturbations and their variation with longitude shows structured atmospheric perturbations at altitudes above 100 km that are likely non‐migrating tides. These perturbations are dominated by zonal wavenumber 2 and 3 with amplitudes greater than 45 %.
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- 2018
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7. The Kelvin–Helmholtz instability at Venus: What is the unstable boundary?
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Daniil Korovinskiy, U. V. Möstl, Helfried K. Biernat, Nikolay Erkaev, Michael Zellinger, Hannes Gröller, and Helmut Lammer
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Solar System ,010504 meteorology & atmospheric sciences ,Solar wind ,Venus ,Astrophysics ,01 natural sciences ,Instability ,Article ,0103 physical sciences ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Physics ,biology ,Astronomy and Astrophysics ,Mechanics ,biology.organism_classification ,Vortex ,Boundary layer ,Magnetospheres ,Space and Planetary Science ,Physics::Space Physics ,Magnetopause ,Astrophysics::Earth and Planetary Astrophysics ,Magnetohydrodynamics - Abstract
Highlights ► We study the Kelvin–Helmholtz instability at boundary layers around of Venus. ► The stability of the induced magnetopause and the ionopause is examined. ► The ionopause seems to be stable due to a large density jump across this boundary. ► The instability evolves into its nonlinear phase on the magnetopause at solar maximum. ► Loss rates are therefore lower than previously assumed., The Kelvin–Helmholtz instability gained scientific attention after observations at Venus by the spacecraft Pioneer Venus Orbiter gave rise to speculations that the instability contributes to the loss of planetary ions through the formation of plasma clouds. Since then, a handful of studies were devoted to the Kelvin–Helmholtz instability at the ionopause and its implications for Venus. The aim of this study is to investigate the stability of the two instability-relevant boundary layers around Venus: the induced magnetopause and the ionopause. We solve the 2D magnetohydrodynamic equations with the total variation diminishing Lax–Friedrichs algorithm and perform simulation runs with different initial conditions representing the situation at the boundary layers around Venus. Our results show that the Kelvin–Helmholtz instability does not seem to be able to reach its nonlinear vortex phase at the ionopause due to the very effective stabilizing effect of a large density jump across this boundary layer. This seems also to be true for the induced magnetopause for low solar activity. During high solar activity, however, there could occur conditions at the induced magnetopause which are in favour of the nonlinear evolution of the instability. For this situation, we estimated roughly a growth rate for planetary oxygen ions of about 7.6 × 1025 s−1, which should be regarded as an upper limit for loss due to the Kelvin–Helmholtz instability.
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- 2011
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8. Exospheres and Energetic Neutral Atoms of Mars, Venus and Titan
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Herbert Lichtenegger, Magda Delva, Jean-Yves Chaufray, Yoshifumi Futaana, H. Todd Smith, Hannes Gröller, Alessandro Mura, Philippe Garnier, Swedish Institute of Space Physics [Kiruna] (IRF), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Centre d'étude spatiale des rayonnements (CESR), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), CNRS, UMR5187, F-31028 Toulouse, France, Institut für Weltraumforschung = Space Research institute [Graz] (IWF), Osterreichische Akademie der Wissenschaften (ÖAW), Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Institut für Weltraumforschung [Graz] (IWF), and Consiglio Nazionale delle Ricerche (CNR)
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Physics ,010504 meteorology & atmospheric sciences ,biology ,Energetic neutral atom ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Astronomy and Astrophysics ,Venus ,Mars Exploration Program ,biology.organism_classification ,01 natural sciences ,7. Clean energy ,Astrobiology ,Atmosphere ,symbols.namesake ,Planetary science ,13. Climate action ,Space and Planetary Science ,Planet ,0103 physical sciences ,symbols ,Titan (rocket family) ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Exosphere - Abstract
International audience; Our understanding of the upper atmosphere of unmagnetized bodies such as Mars, Venus and Titan has improved significantly in this decade. Recent observations by in situ and remote sensing instruments on board Mars Express, Venus Express and Cassini have revealed characteristics of the neutral upper atmospheres (exospheres) and of energetic neutral atoms (ENAs). The ENA environment in the vicinity of the bodies is by itself a significant study field, but ENAs are also used as a diagnostic tool for the exosphere and the interaction with the upstream plasmas. Synergy between theoretical and modeling work has also improved considerably. In this review, we summarize the recent progress of our understanding of the neutral environment in the vicinity of unmagnetized planets.
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- 2011
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9. Altitude profiles of O2 on Mars from SPICAM stellar occultations
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Eric Quémerais, Nikole K. Lewis, Hannes Gröller, Franck Montmessin, Tommi Koskinen, Bill R. Sandel, Roger V. Yelle, Jean-Loup Bertaux, Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Department of Earth, Atmospheric and Planetary Sciences [MIT, Cambridge] (EAPS), Massachusetts Institute of Technology (MIT), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and HELIOS - LATMOS
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Atmospheres ,Secondary atmosphere ,Stellar occultations ,Aeronomy ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,Mars ,Astronomy and Astrophysics ,Atmosphere of Mars ,Astrophysics ,Mars Exploration Program ,Ultraviolet observations ,Atmospheric sciences ,Atmosphere ,Stars ,Altitude ,13. Climate action ,Space and Planetary Science ,composition ,atmosphere ,Mixing ratio ,Environmental science - Abstract
International audience; We determine the first altitude profiles of O2 in the important photochemical region below 120 km in the atmosphere of Mars by analyzing Mars Express/SPICAM ultraviolet observations of six occultations of stars by the atmosphere. Over the range of 90–130 km the altitude-averaged mixing ratio of O2 relative to the major constituent CO2 varies in space and time in the range of 3.1×10-3 to 5.8×10-3, with a mean value of 4.0×10-3. This mean value exceeds by a factor of 3–4 those reported earlier for the lower atmosphere. However, some of the O2 abundance and mixing ratio profiles determined here are similar to those measured by Viking in 1976 in the upper atmosphere.
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- 2015
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10. Outgassing History and Escape of the Martian Atmosphere and Water Inventory
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Matthias Grott, Eric Chassefière, Achim Morschhauser, Doris Breuer, Véronique Dehant, Lê Binh San Pham, Hannes Gröller, Petra Odert, Olivier Mousis, Özgür Karatekin, Helmut Lammer, Paul B. Niles, Ernst Hauber, and U. V. Möstl
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010504 meteorology & atmospheric sciences ,Thermal escape ,Amazonian ,Early Mars ,Atmospheric evolution ,FOS: Physical sciences ,01 natural sciences ,Astrobiology ,Young Sun ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Volcanic outgassing ,Nonthermal escape ,010303 astronomy & astrophysics ,Physics::Atmospheric and Oceanic Physics ,Astrophysics::Galaxy Astrophysics ,0105 earth and related environmental sciences ,Earth and Planetary Astrophysics (astro-ph.EP) ,Magma ocean ,Secondary atmosphere ,Atmospheric escape ,Noachian ,Astronomy and Astrophysics ,Mars Exploration Program ,Atmosphere of Mars ,Outgassing ,13. Climate action ,Space and Planetary Science ,Impacts ,Hesperian ,Astrophysics::Earth and Planetary Astrophysics ,Geology ,Astrophysics - Earth and Planetary Astrophysics - Abstract
The evolution and escape of the martian atmosphere and the planet's water inventory can be separated into an early and late evolutionary epoch. The first epoch started from the planet's origin and lasted $\sim$500 Myr. Because of the high EUV flux of the young Sun and Mars' low gravity it was accompanied by hydrodynamic blow-off of hydrogen and strong thermal escape rates of dragged heavier species such as O and C atoms. After the main part of the protoatmosphere was lost, impact-related volatiles and mantle outgassing may have resulted in accumulation of a secondary CO$_2$ atmosphere of a few tens to a few hundred mbar around $\sim$4--4.3 Gyr ago. The evolution of the atmospheric surface pressure and water inventory of such a secondary atmosphere during the second epoch which lasted from the end of the Noachian until today was most likely determined by a complex interplay of various nonthermal atmospheric escape processes, impacts, carbonate precipitation, and serpentinization during the Hesperian and Amazonian epochs which led to the present day surface pressure., 49 pages, 14 figures
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- 2013
11. Venus' atomic hot oxygen environment
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Valery I. Shematovich, Wolfgang Macher, Helmut Lammer, Helfried K. Biernat, M. Pfleger, Ute Amerstorfer, Yu. N. Kulikov, Hannes Gröller, and Herbert Lichtenegger
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Atmospheric Science ,Soil Science ,Venus ,Aquatic Science ,Inelastic scattering ,Oceanography ,Atmosphere ,Geochemistry and Petrology ,Earth and Planetary Sciences (miscellaneous) ,Astrophysics::Solar and Stellar Astrophysics ,Earth-Surface Processes ,Water Science and Technology ,Quenching ,Physics ,Ecology ,biology ,Scattering ,Paleontology ,Forestry ,biology.organism_classification ,Corona ,Geophysics ,Space and Planetary Science ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,Hot particle ,Atomic physics ,Excitation - Abstract
[1] We present a Monte Carlo study of the atomic hot oxygen corona of Venus. In this model we consider elastic, inelastic, and quenching collisions between the traced hot particle and the ambient neutral atmosphere as well as differential cross sections to determine the scattering angle in the collisions. We also include rotational and vibrational excitation energies for the calculation of the initial energy of the produced hot oxygen atoms. Our results indicate that the differential cross sections and the fraction between elastic, inelastic, and quenching collisions are the most sensitive parameters which effect the corona density. We found that the hot O densities inferred from PVO observations can only be reproduced during high solar activity based on a forward scattering model but without inelastic and quenching collisions. The corona densities for low solar activity (VEX solar conditions) are about a factor of 2–3 smaller than for high solar activity.
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- 2010
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12. Geophysical and atmospheric evolution of habitable planets
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Günter Stangl, Glenn J. White, Thomas Henning, Doris Breuer, W. Hausleitner, Helfried K. Biernat, Jean-Mathias Grießmeier, Andreas Quirrenbach, Jonathan I. Lunine, Hannes Gröller, Eric Chassefière, Tom Herbst, Charles Beichman, Yuri N. Kulikov, Richard Lundin, Alan J. Penny, Herbert Lichtenegger, René Liseau, Uwe Motschmann, Helmut Lammer, Carlos Eiroa, Lisa Kaltenegger, Francesco Paresce, Tilman Spohn, Petra Odert, John Parnell, François Leblanc, Heike Rauer, Nikolai V. Erkaev, Esa Kallio, A. Stadelmann, Jean Schneider, Huub Röttgering, Martin Leitzinger, Maxim L. Khodachenko, Alain Léger, Arnold Hanslmeier, Giovanna Tinetti, Siegfried J. Bauer, William C. Danchi, Frances Westall, Malcolm Fridlund, Daphne Stam, Franck Selsis, Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Laboratoire d'Astrophysique de Bordeaux [Pessac] (LAB), Université de Bordeaux (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'astrodynamique, d'astrophysique et d'aéronomie de bordeaux (L3AB), Université Sciences et Technologies - Bordeaux 1-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire aquitain des sciences de l'univers (OASU), Centre de Recherche Astrophysique de Lyon (CRAL), École normale supérieure - Lyon (ENS Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Interactions et dynamique des environnements de surface (IDES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Netherlands Institute for Radio Astronomy (ASTRON), Polar Geophysical Institute of Russian Academy of Sciences (PGI), Russian Academy of Sciences [Moscow] (RAS), Institute of Computational Modelling of the Russian Academy of Sciences (ICM SB RAS), Siberian Branch of the Russian Academy of Sciences (SB RAS), Finnish Meteorological Institute (FMI), Swedish Institute of Space Physics [Kiruna] (IRF), Centre de biophysique moléculaire (CBM), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC), Institute of Physics [Graz], Karl-Franzens-Universität [Graz, Autriche], NASA ExoPlanet Science Institute (NExScI), California Institute of Technology (CALTECH), NASA Goddard Space Flight Center (GSFC), Universidad Autonoma de Madrid (UAM), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Max-Planck-Institut für Astronomie (MPIA), Max-Planck-Gesellschaft, Harvard-Smithsonian Center for Astrophysics (CfA), Harvard University [Cambridge]-Smithsonian Institution, Institut d'astrophysique spatiale (IAS), Department of Radio and Space Science [Göteborg], Chalmers University of Technology [Göteborg], Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Institut für Theoretische Physik [Braunschweig], Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Istituto Nazionale di Astrofisica (INAF), Department of Geology and Petroleum Geology [Aberdeen], University of Aberdeen, STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC), Landessternwarte Königstuhl [ZAH] (LSW), Universität Heidelberg [Heidelberg], Leiden Observatory [Leiden], Universiteit Leiden [Leiden], Observatoire de Paris - Site de Meudon (OBSPM), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), SRON Netherlands Institute for Space Research (SRON), University College of London [London] (UCL), Department of Physics and Astronomy [Milton Keynes], The Open University [Milton Keynes] (OU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université d'Orléans (UO)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Karl-Franzens-Universität Graz, Universidad Autónoma de Madrid (UAM), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Harvard University-Smithsonian Institution, Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Universität Heidelberg [Heidelberg] = Heidelberg University, and Universiteit Leiden
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010504 meteorology & atmospheric sciences ,[PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,Kepler-69c ,Habitability ,Rare Earth hypothesis ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,Planets ,Environment ,01 natural sciences ,Astrobiology ,Physics::Geophysics ,Eccentric Jupiter ,Magnetics ,Galactic habitable zone ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,Terrestrial planets ,010303 astronomy & astrophysics ,Physics::Atmospheric and Oceanic Physics ,0105 earth and related environmental sciences ,Radiation ,Planetary habitability ,Atmosphere ,Astronomy ,Water ,Geophysics ,Agricultural and Biological Sciences (miscellaneous) ,Habitability of orange dwarf systems ,Earth analog ,13. Climate action ,Space and Planetary Science ,Atmosphere evolution ,Terrestrial planet ,Astrophysics::Earth and Planetary Astrophysics ,Evolution, Planetary ,Geology - Abstract
International audience; The evolution of Earth-like habitable planets is a complex process that depends on the geodynamical and geophysical environments. In particular, it is necessary that plate tectonics remain active over billions of years. These geophysically active environments are strongly coupled to a planet's host star parameters, such as mass, luminosity and activity, orbit location of the habitable zone, and the planet's initial water inventory. Depending on the host star's radiation and particle flux evolution, the composition in the thermosphere, and the availability of an active magnetic dynamo, the atmospheres of Earth-like planets within their habitable zones are differently affected due to thermal and nonthermal escape processes. For some planets, strong atmospheric escape could even effect the stability of the atmosphere
- Published
- 2010
- Full Text
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13. Variability of solar/stellar activity and magnetic field and its influence on planetary atmosphere evolution
- Author
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Manuel Güdel, Maxim L. Khodachenko, Bibiana Fichtinger, Herbert Lichtenegger, Malcolm Fridlund, Kristina G. Kislyakova, Helmut Lammer, Hannes Gröller, Sandro Krauss, Dmitry Bisikalo, Mats Holmström, Teimuraz V. Zaqarashvili, Yuri N. Kulikov, W. Hausleitner, Arnold Hanslmeier, Martin Leitzinger, Petra Odert, Heike Rauer, Ignasi Ribas, Valery I. Shematovich, and Jorge Sanz-Forcada
- Subjects
Solar System ,010504 meteorology & atmospheric sciences ,WSO-UV ,atmosphere evolution ,01 natural sciences ,Astrobiology ,Atmosphere ,Young Sun ,Planet ,0103 physical sciences ,Astrophysics::Solar and Stellar Astrophysics ,010303 astronomy & astrophysics ,0105 earth and related environmental sciences ,Physics ,solar proxies ,Secondary atmosphere ,Energetic neutral atom ,Astronomy ,Geology ,Mars Exploration Program ,Exoplanet ,Solar wind ,PLATO ,solar wind ,13. Climate action ,Space and Planetary Science ,ENAs ,Physics::Space Physics ,Astrophysics::Earth and Planetary Astrophysics ,solar activity - Abstract
It is shown that the evolution of planetary atmospheres can only be understood if one recognizes the fact that the radiation and particle environment of the Sun or a planet’s host star were not always on the same level as at present. New insights and the latest observations and research regarding the evolution of the solar radiation, plasma environment and solar/stellar magnetic field derived from the observations of solar proxies with different ages will be given. We show that the extreme radiation and plasma environments of the young Sun/stars have important implications for the evolution of planetary atmospheres and may be responsible for the fact that planets with low gravity like early Mars most likely never build up a dense atmosphere during the first few 100 Myr after their origin. Finally we present an innovative new idea on how hydrogen clouds and energetic neutral atom (ENA) observations around transiting Earth-like exoplanets by space observatories such as the WSO-UV, can be used for validating the addressed atmospheric evolution studies. Such observations would enhance our understanding on the impact on the activity of the young Sun on the early atmospheres of Venus, Earth, Mars and other Solar System bodies as well as exoplanets.
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