Session - Planetary space weather and its impacts in Solar System exploration

C. Plainaki, M. Andriopoulou, I. Dandouras, A. Radioti

The session welcomes papers on all aspects of the conditions in the Sun, solar wind and magnetospheric plasmas, at different planetary systems of our Solar System, that can influence the performance and reliability of space-borne technological systems. Special emphasis will be given to papers on space weather impacts that affect planetary exploration, e.g. environmental assessment for JUICE and for planetary candidate missions under the ESA M4 and S2 calls, lessons learned from recent and existing missions such as MEX, VEX, and Cassini. Focus will be given in cross-disciplinary issues, including:

- the interaction of solar wind/magnetospheric plasmas with planetary/satellite ionospheres and thick (e.g. at Jupiter, Saturn, Uranus, Mars, Venus, Titan) or tenuous (e.g. Ganymede, Europa, Mercury, our Moon) atmospheres, including the generation of auroras
- the satellite interactions with their neutral environments and dust
- the variability of the magnetospheric regions under different solar wind conditions
- the inter-comparisons of space weather conditions in different planetary environments

Contributions addressing previous (e.g. CHANDRAYAAN-1, KAGUYA, VENUS EXPRESS), present (e.g. CASSINI, MARS EXPRESS, ROSETTA, MAVEN, MESSENGER, VAN ALLEN PROBES) and forthcoming (e.g. BEPI COLOMBO, JUNO, JUICE, MMS) in situ observations are welcome. Abstracts on theoretical modeling and simulations of planetary space weather conditions, possibly destined for end-users of space weather services, are extremely welcome. Inter-comparisons and interpretation of measurements at different planetary systems and quantification of the possible effect of the environment interactions on components and systems (e.g. radiation doze studies) are strongly encouraged.

Talks
Wednesday November 25, 12:00 - 13:00, Delvaux
Thursday November 26, 11:00 - 13:00, Delvaux

Poster Viewing
Wednesday November 25, 10:00 - 11:00, Poster area

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Talks : Time schedule

Wednesday November 25, 12:00 - 13:00, Delvaux

12:00	Planetary Space Weather Services for the Europlanet 2020 Research Infrastructure	Andre, N et al.	Invited p-Poster
	N. André, M. Grande, on behalf of the PSWS Team
	Centre National de la Recherche Scientifique (France), Aberystwyth University (UK), Deutsches Zentrum für Luft- und Raumfahrt e.V. Cologne (Germany), Escuela Técnica Superior de Ingeniería (ETSI) of the University of the Basque Country (UPV/EHU), GFI Informatique (France), Ústav fyziky atmosféry AV ČR, v.v.i IAP (Czech Republic), University College London (UCL) (UK), Observatoire de Paris (France), Centrum Badań Kosmicznych Polskiej Akademii Nauk SRC/PAS (Poland), Magyar Tudományos Akadémia Wigner Fizikai Kutatóközpont Wigner RCP (Hungary)
	Under Horizon 2020, the Europlanet 2020 Research Infrastructure (EPN2020-RI) will include an entirely new Virtual Access Service, WP5 VA1 “Planetary Space Weather Services” (PSWS) that will extend the concepts of space weather and space situational awareness to other planets in our Solar System and in particular to spacecraft that voyage through it. VA1 will make five entirely new ‘toolkits’ accessible to the research community and to industrial partners planning for space missions: a general planetary space weather toolkit, as well as three toolkits dedicated to the following key planetary environments: Mars (in support ExoMars), comets (building on the expected success of the ESA Rosetta mission), and outer planets (in preparation for the ESA JUICE mission to be launched in 2022). This will give the European planetary science community new methods, interfaces, functionalities and/or plug-ins dedicated to planetary space weather in the tools and models available within the partner institutes. It will also create a novel event-diary toolkit aiming at predicting and detecting planetary events like meteor showers and impacts. A variety of tools (in the form of web applications, standalone software, or numerical models in various degrees of implementation) are available for tracing propagation of planetary and/or solar events through the Solar System and modelling the response of the planetary environment (surfaces, atmospheres, ionospheres, and magnetospheres) to those events. But these tools were not originally designed for planetary event prediction and space weather applications. So WP10 JRA4 “Planetary Space Weather Services” (PSWS) will provide the additional research and tailoring required to apply them for these purposes. The overall objectives of this JRA will be to review, test, improve and adapt methods and tools available within the partner institutes in order to make prototype planetary event and space weather services operational in Europe at the end of the programme.
12:08	Mapping Ganymede’s Time Variable Aurora in the Search for a Subsurface Ocean (invited)	Saur, J et al.	Invited p-Poster
	J. Saur[1], S. Duling[1], L. Roth[2], X. Jia[3], D.F. Strobel[4], P.D. Feldman[4], U. Christensen[6], K.D. Retherford[7], M.A. McGrath[8], F. Musacchio[1], A. Wennmacher[1], F.M. Neubauer[1], S. Simon[9], O. Hartkorn[1]
	[1] University of Cologne; [2] KTH Stockholm; [3] Univ. Michigan; [4] Johns Hopkins Univ.; [6] MPS Goettingen; [7] SWRI; [8] NASA Marshall; [9] Georgia Inst. Tech.
	An important unresolved question about Jupiter’s moon Ganymede is whether Ganymede harbors a subsurface water ocean under its icy crust. Here we present a new mean to address this question through observations of Ganymede’s two auroral ovals whose locations are controlled by Ganymede’s magnetic field environment. Due to Jupiter’s time-variable magnetic field, the locations of Ganymede’s auroral ovals are expected to rock towards and away from Jupiter. A saline, electrically conductive water ocean will modify the time-variable field due to electromagnetic induction effects and will reduce the rocking. We present HST observations, which are particularly designed to measure the rocking of Ganymede’s ovals. Our analysis shows that the auroral ovals only weakly rock in concert with the time-variable Jovian magnetic field. This weak rocking of the ovals is consistent with shielding of the time-variable field due to electromagnetic induction in a saline subsurface ocean on Ganymede.
12:16	Space weather on Titan	Coustenis, A et al.	Invited e-Poster
	A. Coustenis[1], J. Lilensten[2], I. Dandouras[3]
	[1] LESIA, Paris Observatory, Meudon, France; [2] IPAG, Grenoble, France; [3] IRAP, CNRS and Paul Sabatier Toulouse Univ., Toulouse, France
	Titan is the only other body in our Solar System besides our own planet to have a dense atmosphere made essentially of molecular nitrogen (~97%), and hosting an active and complex organic chemistry created by the photolysis of methane (~2% in the stratosphere) and its interaction with nitrogen and hydrogen (at ~0.1%). Since Titan can be inside or outside of the Saturn’s magnetosphere, particle precipitation, hence ionization can be very variable depending on the position of the satellite and local plasma conditions. The ionization profile in the atmosphere of Titan is however well known, although the formation of the large atmospheric molecules at all altitudes is not. In this presentation, we examine some of the related salient features. Solar EUV – XUV radiation, energetic plasma from Saturn’s magnetosphere and from the solar wind, and cosmic rays are the main sources of the ionization of the neutral gas in Titan’s atmosphere and they are also responsible for the formation of the observed three layers of detached haze in the atmosphere where we can study the relation between ionizing radiation and haze formation as well as seasonal effects, among other. We also look at what role the magnetic field of Saturn can play in the observed atmospheric escape. Finally, we will discuss expectations from future space missions on this important subject.
12:24	Ultraviolet auroral emissions on giant planets	Grodent, D et al.	Invited Oral
	Denis Grodent[1], Bertrand Bonfond[1], Aikaterini Radioti[1], Jacques Gustin[1], Jean-Claude Gérard[1], Maïté Dumont[1], Benjamin Palmaerts[1,2]
	[1] Laboratoire de Physique Atmosphérique et Planétaire, Université de Liège, Belgium; [2] Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany
	The aurorae on Jupiter and Saturn are the most powerful proper ultraviolet emissions in our solar system, after the Sun’s. They can only be observed outside the absorbing atmosphere of the Earth with space telescopes such as the Hubble Space Telescope or the Hisaki Telescope, or from Spacecraft orbiting these planets, like Cassini for Saturn and Juno for Jupiter. We will review the types of observation that can be obtained with these different instruments and how this information can be used to interpret the auroral emissions.
12:41	Airglow emissions modelling for Europa and Ganymede	Cessateur, G et al.	Oral
	Gaël Cessateur[1], Mathieu Barthelemy[2]
	[1] Belgian Institute for Space Aeronomy, BIRA-IASB, Brussels, Belgium; [2] Institut de Planétologie et d'Astrophysique de Grenoble, Université Joseph Fourier, Grenoble, France
	Planetary space weather studies are nowadays an aera of high scientific interest, especially in the frame of the exploration of planetary environments such as the Galilean moons. We will focus here on the impact of the solar UV radiation which is responsible for the photoionization and photodissociation processes, but also the impact of precipitating particles. A 1-D model has been developed in order to infer airglow emissions from Europa and Ganymede, from neutral atmospheric models. Considering various production and loss mechanisms, we estimate red and green line emission for atomic oxygen, as well as auroral emission, for the oxygen lines at 130.5 and 135.5 nm. Comparison with observations such as in situ measurements from Galileo, or remote observations from the Hubble Space Telescope, shows a good agreement that ensures us to provide reasonable constraints for the JUICE mission. We will also present a sensibility study regarding the chosen solar UV flux on dayglow emission estimations. From transient events such as flares to long term solar variability, we show that an accurate knowledge about the solar UV flux in mandatory in order to disentangle between different neutral atmospheric models.

Thursday November 26, 11:00 - 13:00, Delvaux

11:00	Ionosphere-neutral atmosphere coupling in the Solar System and its dependence on space weather conditions	Witasse, O et al.	Invited Oral
	Olivier Witasse[1], Pierre-Louis Blelly[2], Hermann Opgenoorth[3], David Andrews[3], Beatriz Sanchez-Cano[4], Mark Lester[4]
	[1] European Space Agency, Noordwijk, The Netherlands; [2] Institut de Recherche en Astrophysique et Planétologie, Toulouse, France; [3] Swedish Institute of Space Physics, Uppsala, Sweden; [4] University of Leicester, UK
	Space Weather conditions interact with planetary environment in a complex way that leads to a very dynamical ionosphere-neutral atmosphere couplings. External drivers as the solar wind (magnetic field and energetic particles) or the solar flux (EUV and soft X-rays) and internal sources as gravity waves (from the lower atmosphere) or intrinsic magnetic field (including crustal field, in the case of Mars) compete for controlling the dynamics and the energetics of the near space planetary environment. This competition comes to an end in the upper atmosphere, where the couplings between the ionosphere and the thermosphere are monitored by the energy released in the medium, through photochemical and collisional processes. This presentation will describe the main mechanisms that link the ionosphere-atmosphere system, and show some examples of space weather effects. We will discuss modelling efforts and how data can validate our understanding of the physical processes. The particular case of Mars will be outlined, with the a data set acquired over a full solar cycle by the Mars Express spacecraft. Various examples for Venus, Earth and the giant planets will be also given, to highlight different conditions in our solar system. Questions to be answered by future missions will be addressed at the end.
11:17	ESA's Interplanetary and Planetary Radiation Model for Human Spaceflight (IPRAM) Study	Jiggens, P et al.	Oral
	Piers Jiggens[1], Daniel Heynderickx[2], Fan Lei[3], Pete Truscott[4], Rami Vainio[5], Angels Aran[6], Blai Sanahuja[6], Anna Vuori[5], Osku Raukunen[5], Andrés Galvez[1]
	[1] European Space Agency (ESA); [2] DH Consultancy, Belgium; [3] RadMod Research, U.K.; [4] Kallisto Consultancy Ltd, U.K.; [5] Department of Physics and Astronomy, University of Turku, Finland; [6] Dep. d'Astronomia i Meteorologia, Universitat de Barcelona, Spain
	Solar Energetic Particles (SEPs) is the term given to particle radiation resulting from phenomena in the solar corona; solar flares and especially from Coronal Mass Ejections (CMEs). These particles are an important environmental factor to be considered by spacecraft designers as a result of degradation caused by ionising and displacement damage as well as single event effects (SEEs) and hazards to humans. These particles arrive in concentrated bursts, known as Solar Particle Events (SPEs) resulting from solar phenomena which are highly variable in both their frequency and magnitude. For interplanetary missions at energies up to hundreds of MeV SEPs are the dominant contributors for particle radiation in the cruise phase, however, at higher energies the contribution of Galactic Cosmic Rays (GCRs) can contribute the majority of particle fluxes. For manned missions the high energy component of the solar particle spectra is very important due to the thick shielding present on such spacecraft and the production of secondaries inside this shielding. For missions away from the Earth it is important to quantify the impact on the fluxes of SEPs as particles propagate through the interplanetary medium. Once on the surface planetary effects such as shielding by regolith and resulting secondary (albedo) radiation must be considered in order to accurately determine likely mission cumulative doses. An internal ESA study called NEMS – Near-Earth Exploration Minimum System - was conducted at ESA’s Concurrent Design Facility (CDF) between March and April 2011. Its aim was to investigate and report on the main trade-offs, system drivers and critical risk areas associated with even the most basic human exploration beyond Earth-Moon system. As a outcome of this study, ESA's General Studies Programme (GSP) funded the IPRAM study as one of a set of studies aimed at addressing uncertainties, risks and knowledge gaps independent from specific exploration targets and mission scenarios ultimately being considered. In keeping with this philosophy IPRAM investigated the radiation doses in humans with respect to internationally established dose limits for missions to the Moon, Mars and a near-Earth asteroid. Gaps in existing radiation environment and effects standards adversely affect human spaceflight developments. The most important drivers in the domain of interplanetary and planetary radiation environments were investigated, identifying appropriate data sources and modelling methods to address the needs of future interplanetary manned mission design and operation. We present the results of the IPRAM study which includes new radiation estimates, for each of the three case studies, for a range of shielding thicknesses and an approximate manned spacecraft shielding distribution. This combined a comprehensive set of spacecraft and neutron monitor data with statistical models and physical modelling of particle transport for helioradial distances away from 1 AU. the operational aspects for manned missions were also addressed in terms of required warning times in the case of severe SPEs before doses reached unacceptable levels for mission safety. A possible roadmap for future developments was derived, as well as a gap analysis of environment data and models of the radiation environment and effects on humans and spacecraft components. Although the focus of IPRAM was on the impact of manned space missions the tools could also be applied to future robotic planetary exploration.
11:28	Titan's plasma interaction and space weather effects	Coates, A et al.	Invited Oral
	Andrew Coates
	UCL-MSSL
	Titan is the only moon in the solar system with a substantial atmosphere, with a surface pressure of 1.5 bars. The main neutral constituents are nitrogen and methane. Cassini has revealed significant chemical complexity in the upper atmosphere and ionosphere, with a mix of heavy neutrals (Waite et al., 2005, 2007), positive ions (Crary et al., 2009) and negative ions (Coates et al., 2007, 2009, Waite et al. (2007), Wellbrock et al., 2013. The heavy species may fall to the surface as tholins, but some escape from the ionosphere is also seen (Coates et al., 2012, Westlake et al., 2012). A major surprise from Cassini was that, while Titan is still important as a source for the magnetosphere, it is less so than other sources such as Enceladus. Titan’s orbit at 20 Saturn radii means that its upstream plasma environment is usually Saturn’s magnetosphere and plasma disk (e.g. Arridge et al., 2011) but at times Titan can encounter Saturn’s magnetosheath (Bertucci et al. 2008) and also the solar wind (Bertucci et al. 2015) so space weather effects are direct at times. In this talk we will review Saturn’s ionosphere, composition and effects, and discuss the upstream conditions and possible space weather effects.
11:45	Space Weather Phenomena at Comets	Jones, G et al.	Invited Oral
	Geraint H. Jones[1,2]
	[1] Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking RH5 6NT, UK; [2] The Centre for Planetary Sciences at UCL/Birkbeck, Gower Street, London WC1E 6BT, UK
	When a comet nucleus is close to the Sun, it can act as a major source of neutral gases. These species are ionized by solar radiation and other processes, after which they join the flow of the solar wind past the comet. This addition of plasma to the solar wind leads to the local deceleration of the wind, the draping of the heliospheric magnetic field, and hence to the formation of an induced magnetosphere and magnetotail. The latter is visible as the comet’s ion tail, the existence of which was one of the key original pieces of evidence indicating the presence of a solar wind. The ionized components of comets are sensitive to changes in the solar wind: comets’ ion tails are seen to change direction in response to speed changes, and often display complex, dynamic structures, many examples of which have been associated with the stream interactions and interplanetary coronal mass ejections. Comets’ ion tails are occasionally observed to detach completely before reforming: occurrences known as disconnection events. These are often associated with crossings of the heliospheric current sheet. As well as remote observations, we also have in situ measurements of cometary environments as they respond to space weather changes. The highly successful ESA Rosetta mission to Comet 67P/Churuymov-Gerasimenko is currently providing invaluable long-term observations of this type. Solar energetic particle events and solar UV/X-ray flares may also have observable effects on a cometary environment, in particular through changes in the ionization rates of neutral species. A review is presented of the behaviour of active comets in response to changes in the solar wind, illustrated by remote and in situ observations. Finally, the value of comets as remote probes of solar wind conditions is discussed.
12:02	Cosmic rays interaction with comets and its impact on cometary isotopic and chemical composition	Maggiolo, R et al.	Oral
	Romain Maggiolo[1], Guillaume Gronoff[2], Cristopher Mertens[2], Vladimir Airapetian[3], Johan De Keyser[1], Gael Cessateur[1], Frederik Dhooghe[1], Herbert Gunell[1]
	[1] Belgian Institute for Space Aeronomy, Belgium; [2] Nasa Langley Research Center, Virginia, USA; [3] George Mason University, Virginia,USA
	Comets contain the most pristine material in the solar system. However, since their formation ~4.5 Gy ago, they have been altered by cosmic rays. The galactic and solar cosmic rays have a broad spectrum of energies and interact with the cometary surface and subsurface. This interaction can modify the isotopic ratio in cometary ices and create secondary compounds through radiolysis. We perform a theoretical analysis of the effect of cosmic rays on cometary material. We model the energy deposition of cosmic ray as a function of depth. While low energy cosmic rays interact only with the cometary surface, the most energetic cosmic rays deposit significant amount of energy down to tens of meters. We analyze the consequences of this energy deposition on the isotopic and chemical composition of cometary ices and discuss their implication on the interpretation of cometary observations.
12:13	The MSL/RAD radiation measurement during the cruise to and on the surface of Mars	Guo, J et al.	Oral
	Jingnan Guo
	University of Kiel
	The Radiation Assessment Detector (RAD), on board Mars Science Laboratory's (MSL) rover Curiosity, measures the spectra of both energetic charged and neutral particles along with the radiation dose rate at the surface of Mars. With these first-ever measurements on the Martian surface, RAD observed not only the impulsive and sporadic solar energetic particles (SEPs) but also the galactic cosmic ray (GCR) radiation dose which is influenced by several effects concurrently: [a] short-term diurnal variations of the Martian atmospheric pressure caused by daily thermal tides; [b] long-term seasonal pressure changes in the Martian atmosphere; and [c] the modulation of the primary GCR flux by the solar magnetic field, which correlates with long-term solar activities and heliospheric rotation. RAD also recorded the dose rate during the 253-day cruise phase of MSL from Earth to Mars. There, the measured GCR induced dose rates were as well driven by the changes of heliospheric conditions (i.e., [c]). The RAD cruise and surface dose measurements (due to both SEP and GCR), along with the surface pressure data and the solar modulation factor, are analyzed in order to understand how the long-term influences ([b] and [c]) individually correlate with the measured dose rates.
12:24	Extreme Space Weather at Mercury	Imber, S et al.	Invited Oral
	Imber, S. M.[1], Slavin, J. A.[2]
	[1] University of Leicester, Leicester, UK; [2] University of Michigan, USA
	The large-scale dynamic behavior of Mercury's highly compressed magnetosphere is predominantly powered by magnetic reconnection. Energy and momentum are transferred from the solar wind to the magnetosphere, driving the large-scale circulation of magnetic flux through the system predominantly via the substorm, or loading-unloading cycle. We will present a statistical analysis of the average amplitude, duration and frequency of these loading-unloading events using magnetic field data acquired in orbit about Mercury by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft. The largest amplitude loading-unloading events cycle through ~50% of Mercury’s open flux content. We will analyse the combination of magnetotail and solar wind parameters leading to these extreme events.
12:41	Solar wind and SEP modeling throughout the Solar System based on the ENLIL global heliospheric model	Mays, M et al.	Invited Oral
	M. L. Mays[1,2], J. G. Luhmann[3], D. Odstrcil[4], C. O. Lee[3], H. M. Bain[3], Y. Li[3], N. A. Schwadron[5], M. J. Gorby[5], D.N. Baker[6], R. M. Dewey[6], D. Larson[3], J. Halekas[7], J. Connerney[2], R. A. Mewaldt[8], T. T. von Rosenvinge[2], A.B. Galvin[5], D. G. McComas[9], M. M. Kuznetsova[2]
	[1] Catholic University of America; [2] NASA Goddard Space Flight Center; [3] Space Sciences Laboratory, University of California, Berkeley; [4] George Mason University, Fairfax; [5] University of New Hampshire; [6] University of Colorado Boulder; [7] University of Iowa; [8] Space Radiation Lab, California Institute of Technology; [9] Southwest Research Institute
	The global 3D MHD WSA-ENLIL model (Odstrcil et al., 2004) provides a time-dependent background heliospheric description, into which a spherical shaped CME can be inserted. Understanding gradual SEP events (often driven by CMEs) well enough to forecast their properties at a given location requires a realistic picture of the global background solar wind through which the shocks and SEPs propagate. Accurate descriptions of the heliosphere, and hence modeled SEPs, are achieved by ENLIL only when the background solar wind is well-reproduced and CME parameters are accurate. It is clear from our preliminary runs that the CMEs sometimes generate multiple shocks, some of which fade while others merge and/or strengthen as they propagate. In order to completely characterize the SEP profiles observed at various locations throughout the solar system with the aid of these simulations it is essential to include all of the relevant CMEs and allow enough time for the events to propagate and interact. ENLIL provides solar wind parameters at locations throughout the solar system and additionally one can extract the magnetic topologies of observer-connected magnetic field lines and all plasma and shock properties along those field lines. ENLIL “likelihood/all-clear” forecasting maps provide expected intensity, timing/duration of events at locations throughout the heliosphere with “possible SEP affected areas” color-coded based on shock strength. ENLIL simulations are also useful to drive SEP models such as the Solar Energetic Particle Model (SEPMOD) and Earth-Moon-Mars Radiation Environment Module (EMMREM). In this presentation we demonstrate case studies of solar wind and SEP event modeling at locations throughout the solar system based on WSA-ENLIL+Cone simulations.

Posters

Wednesday November 25, 10:00 - 11:00, Poster area

1	Planetary Space Weather Services for the Europlanet 2020 Research Infrastructure	Andre, N et al.	Invited p-Poster
	N. André, M. Grande, on behalf of the PSWS Team
	Centre National de la Recherche Scientifique (France), Aberystwyth University (UK), Deutsches Zentrum für Luft- und Raumfahrt e.V. Cologne (Germany), Escuela Técnica Superior de Ingeniería (ETSI) of the University of the Basque Country (UPV/EHU), GFI Informatique (France), Ústav fyziky atmosféry AV ČR, v.v.i IAP (Czech Republic), University College London (UCL) (UK), Observatoire de Paris (France), Centrum Badań Kosmicznych Polskiej Akademii Nauk SRC/PAS (Poland), Magyar Tudományos Akadémia Wigner Fizikai Kutatóközpont Wigner RCP (Hungary)
	Under Horizon 2020, the Europlanet 2020 Research Infrastructure (EPN2020-RI) will include an entirely new Virtual Access Service, WP5 VA1 “Planetary Space Weather Services” (PSWS) that will extend the concepts of space weather and space situational awareness to other planets in our Solar System and in particular to spacecraft that voyage through it. VA1 will make five entirely new ‘toolkits’ accessible to the research community and to industrial partners planning for space missions: a general planetary space weather toolkit, as well as three toolkits dedicated to the following key planetary environments: Mars (in support ExoMars), comets (building on the expected success of the ESA Rosetta mission), and outer planets (in preparation for the ESA JUICE mission to be launched in 2022). This will give the European planetary science community new methods, interfaces, functionalities and/or plug-ins dedicated to planetary space weather in the tools and models available within the partner institutes. It will also create a novel event-diary toolkit aiming at predicting and detecting planetary events like meteor showers and impacts. A variety of tools (in the form of web applications, standalone software, or numerical models in various degrees of implementation) are available for tracing propagation of planetary and/or solar events through the Solar System and modelling the response of the planetary environment (surfaces, atmospheres, ionospheres, and magnetospheres) to those events. But these tools were not originally designed for planetary event prediction and space weather applications. So WP10 JRA4 “Planetary Space Weather Services” (PSWS) will provide the additional research and tailoring required to apply them for these purposes. The overall objectives of this JRA will be to review, test, improve and adapt methods and tools available within the partner institutes in order to make prototype planetary event and space weather services operational in Europe at the end of the programme.
2	Mapping Ganymede’s Time Variable Aurora in the Search for a Subsurface Ocean (invited)	Saur, J et al.	Invited p-Poster
	J. Saur[1], S. Duling[1], L. Roth[2], X. Jia[3], D.F. Strobel[4], P.D. Feldman[4], U. Christensen[6], K.D. Retherford[7], M.A. McGrath[8], F. Musacchio[1], A. Wennmacher[1], F.M. Neubauer[1], S. Simon[9], O. Hartkorn[1]
	[1] University of Cologne; [2] KTH Stockholm; [3] Univ. Michigan; [4] Johns Hopkins Univ.; [6] MPS Goettingen; [7] SWRI; [8] NASA Marshall; [9] Georgia Inst. Tech.
	An important unresolved question about Jupiter’s moon Ganymede is whether Ganymede harbors a subsurface water ocean under its icy crust. Here we present a new mean to address this question through observations of Ganymede’s two auroral ovals whose locations are controlled by Ganymede’s magnetic field environment. Due to Jupiter’s time-variable magnetic field, the locations of Ganymede’s auroral ovals are expected to rock towards and away from Jupiter. A saline, electrically conductive water ocean will modify the time-variable field due to electromagnetic induction effects and will reduce the rocking. We present HST observations, which are particularly designed to measure the rocking of Ganymede’s ovals. Our analysis shows that the auroral ovals only weakly rock in concert with the time-variable Jovian magnetic field. This weak rocking of the ovals is consistent with shielding of the time-variable field due to electromagnetic induction in a saline subsurface ocean on Ganymede.
3	Space weather on Titan	Coustenis, A et al.	Invited e-Poster
	A. Coustenis[1], J. Lilensten[2], I. Dandouras[3]
	[1] LESIA, Paris Observatory, Meudon, France; [2] IPAG, Grenoble, France; [3] IRAP, CNRS and Paul Sabatier Toulouse Univ., Toulouse, France
	Titan is the only other body in our Solar System besides our own planet to have a dense atmosphere made essentially of molecular nitrogen (~97%), and hosting an active and complex organic chemistry created by the photolysis of methane (~2% in the stratosphere) and its interaction with nitrogen and hydrogen (at ~0.1%). Since Titan can be inside or outside of the Saturn’s magnetosphere, particle precipitation, hence ionization can be very variable depending on the position of the satellite and local plasma conditions. The ionization profile in the atmosphere of Titan is however well known, although the formation of the large atmospheric molecules at all altitudes is not. In this presentation, we examine some of the related salient features. Solar EUV – XUV radiation, energetic plasma from Saturn’s magnetosphere and from the solar wind, and cosmic rays are the main sources of the ionization of the neutral gas in Titan’s atmosphere and they are also responsible for the formation of the observed three layers of detached haze in the atmosphere where we can study the relation between ionizing radiation and haze formation as well as seasonal effects, among other. We also look at what role the magnetic field of Saturn can play in the observed atmospheric escape. Finally, we will discuss expectations from future space missions on this important subject.
4	Investigating the variations of the photoelectron emission of the surface of the Cluster spacecraft	Andriopoulou, M et al.	p-Poster
	Maria Andriopoulou, Rumi Nakamura, Klaus Torkar, Wolgang Baumjohann
	Space Research Institute, Austrian Academy of Sciences, Graz, Austria
	A sunlit spacecraft that orbits in tenuous plasma regions will be positively charged due to the photoelectrons that escape from its surface. The spacecraft potential can be then determined by the equilibrium of the acting currents, which in this case are the photoelectron current and the current of the ambient electrons. In this work we use multispacecraft observations from the Cluster mission to study the variations of the photoelectron emission over short and long timescales. To derive photoelectron current profiles we used plasma moments and spacecraft potential measurements considering time intervals between the years 2001 and 2004. These profiles can then be used for reconstructing spacecraft potential measurements from spacecraft with active potential control to spacecraft potential measurements with no active control and use those reconstructions to provide plasma density estimates with high accuracy. We will finally discuss the limitations of such determinations when the spacecraft are orbiting in very tenuous plasma regions.
5	Auroral manifestations of the interaction of the solar wind with Saturn	Radioti, A et al.	p-Poster
	A. Radioti, D. Grodent, J.-C. Gérard and B. Bonfond
	LPAP, Institut d’Astrophysique et de Geophysique, Université de Liège, Belgium
	Unlike to Earth, Saturn’s magnetosphere is believed to be influenced by fast planetary rotation and internally driven processes. However, the interaction of the solar wind with the magnetosphere of the giant planet has multiple manifestations in the aurora. Auroral emissions in the dayside region are related to reconnection of the interplanetary magnetic field with the dayside magnetopause at Saturn. There is also auroral evidence of viscous interaction of the solar wind with Saturn’s magnetosphere, which involves magnetic reconnection on a small scale. Additionally, solar wind-induced auroral storms result in dramatic enhancements of the nightside to dawn auroral emissions. Finally, one of the most spectacular auroral features at Earth, a nightside polar arc is observed in the aurora of Saturn for the first time and is possibly related to solar wind driven tail reconnection.
6	Studying the dynamics of Saturn’s inner magnetosphere using injections and microsignature observations	Andriopoulou, M et al.	p-Poster
	Maria Andriopoulou[1], Michelle Thomsen[2], Elias Roussos[3] and members of the ISSI Team "Modes of radial plasma motion in planetary systems"
	[1] Space Research Institute, Austrian Academy of Sciences, Graz, Austria; [2] Planetary Science Institute, Tucson, Arizona USA; [3] Max Planck Institute for Solar System Research, Göttingen, Germany
	In a rotatially dominated magnetosphere such as the Saturnian one, it has been typically difficult to resolve radial plasma motion using direct velocity measurements, especially for determining the local dynamics. The study of well-defined local signatures of radial plasma motion, also known as microsignature events, has inferred a global convection pattern in the inner Saturnian magnetosphere, related to dawnward flows with speeds of a few km/s. However, transient phenomena are also present in the magnetosphere of Saturn, modifying the local dynamics of the system. We will try to understand such transient phenomena by studying complex and bifurcated microsignatures, using data from the LEMMS and CAPS detectors onboard Cassini and to interpret those in combination with injection events, other signatures of radial motion that are observed quite often in the plasma detectors of Cassini.
7	Propagation Tool: comparing HELCATS CIR catalogues derived from white-light images and in-situ measurements	Plotnikov, I et al.	p-Poster
	Illya Plotnikov[1,2], Alexis Rouillard[1,2], Benoit Lavraud[1,2]
	[1] Université de Toulouse; UPS-OMP; IRAP; Toulouse, France; [2] CNRS; IRAP; 9 Av. colonel Roche, BP 44346, F-31028 Toulouse cedex 4, France
	We present the 'propagation tool' that allows users to track the propagation of Coronal Mass Ejections (CMEs) and Corotating Interaction Regions (CIRs) to 1AU. This tool provides access to maps of solar wind outflows from the Sun to 1AU and offers different ways to estimate the location and speed of CMEs and CIRs with time. It also provides access to catalogues of CIRs and CMEs that have been derived by the HELCATS project. The CIR catalogue is derived using white-light images from the HI instruments on STEREO and is here compared with in-situ measurements. We compare the predicted arrival time and speed of the density structures embedded in CIRs with the in-situ arrival of density peaks and the stream interfaces located in the CIR compression regions. This procedure apears to give a very reasonable agreement between the imager prediction and the in-situ detection. We discuss the usefulness of heliospheric imagery at localizing CIRs in 3-D and predicting their arrival time at Earth and any other locations in the heliosphere, such as Rosetta. Backtracking these density signatures to the Sun allows to compare the source region of each CIR with the location of coronal holes on the surface and we possible associate each CIR event to a given coronal hole. This is work is supported by the FP7 HELCATS project #606692 (HELCATS).
8	Heliospheric space weather: Toward operational support of heliospheric missions	Odstrcil, D et al.	p-Poster
	D. Odstrcil[1,2], L. Mays[2], P. MacNeice[2], M. Maddox[2], M. Kuznetsova[2]
	[1] George Mason University; [2] NASA/Goddard Space Flight Center
	Currently, the WSA-ENLIL-Cone modeling system enables faster-than-real time simulations of corotating and transient disturbances in the inner heliosphere. The stable operational version is used by NOAA/SWPC (USA) and MetOffice (UK) for official space weather forecast and by NASA/SWRC (USA) for operational support of heliospheric missions. We present an updated version of this modeling system suitable for operational support in the inner and mid heliosphere, and as a concept, for operational predictions in the outer heliosphere. We will present results relevant to Rosetta (at comet 67P/C-G), Juno (near Jupiter), Cassini (at Saturn), and New Horizons (at Pluto) missions. Attention is given to predicting arrival times of stream interaction regions (SIRs) and coronal mass ejections (CMEs), temporal profiles of ram pressure, and possible impact of energetic particles.
9	Impact of extreme SEP events on the Venusian atmosphere	Nordheim, T et al.	p-Poster
	Tom Nordheim[1],Lewis Dartnell[2], Andrew Coates[1], Geraint Jones[1]
	[1] Jet Propulsion Laboratory, California Institute of Technology; [2] Space Research Centre, University of Leicester
	Planetary atmospheres are constantly exposed to incoming cosmic rays – high energy charged particles of solar and galactic origin. The most energetic of these cosmic ray particles are capable of affecting deep atmospheric layers through extensive nuclear and electromagnetic secondary particle cascades. Below the penetration depth of solar ultraviolet photons, cosmic rays are typically the primary ionization agent and therefore represents an important driver of atmospheric chemistry and electrical phenomena in planetary atmospheres. It is therefore crucial to quantify the amount of energy deposited by cosmic rays, as this is required to produce atmospheric ionization profiles. While the galactic cosmic ray (GCR) component represents a steady background flux, which changes slowly with the solar cycle, the solar energetic particle (SEP) component may produce sporadic enhancements in cosmic ray flux many orders of magnitude above background levels. For Venus, with its thick atmosphere, close proximity to the Sun and lack of an intrinsic magnetic field, the effects of such SEP events are more pronounced than at the Earth. Here we present Monte Carlo modeling results for atmospheric ionization at Venus due to strong SEP events. We consider several worst-case SEP events as observed in the space age, as well as two prototypical extreme SEP events as reconstructed from the historic record: the Carrington event of 1859 and the so-called 775 AD event.
10	Cosmic rays - Venusian atmosphere interactions during different periods of solar activity	Plainaki, C et al.	e-Poster
	Christina Plainaki[1], Pavlos Paschalis[2], Davide Grassi[1], Helen Mavromichalaki[2], Maria Andriopoulou[3]
	[1] INAF - IAPS, Via del Fosso del Cavaliere, 00133 Roma, Italy; [2] Nuclear and Particle Physics Section, Physics Dpt. of the National and Kapodistrian University of Athens, 15784, Athens, Greece; [3]Space Science Institute, Austrian Academy of  Science, Graz, Austria
	Interactions of the galactic and solar cosmic ray particles with the atmosphere of Venus result in extensive nuclear and electromagnetic cascades that can affect cloud formation and chemistry in deep atmospheric layers. Variabilities in the energy spectrum of these incoming cosmic ray particles and in their integrated flux -as well as their direction- would result in variations of the cascade properties with possible effects in the local neutral densities, particle ionization and escape. It is therefore of significant importance to understand and quantify such space weather phenomena at Venus, in the context of future mission preparation and also data interpretations of previous missions (e.g. VEX). In this work, we perform a calculation of the atmosphere ionization and ion production rates caused by cosmic rays, as a function of depth in the Venusian atmosphere. We examine the interactions of the planet's atmosphere with: a) galactic cosmic rays, during solar maximum conditions; b) galactic cosmic rays, during solar minimum conditions; c) solar cosmic rays during SEP conditions. The scenario (c) was studied for two paradigm cases: the very energetic SEP/GLE event of Sept. 1989 and the recent less energetic SEP/GLE event of May 2012. For the second case, we considered the SEP properties (integrated flux and spectrum) obtained by the NMBANGLE PPOLA model (Plainaki et al., 2010; 2014) applied previously for the Earth case, scaled to the distance of Venus (i.e. 0.72 AU from the Sun). In order to simulate the actual cascade in the atmosphere initiated by the incoming cosmic ray fluxes we use a Monte Carlo modeling technique based on the Geant4 software, previously applied for the Earth case (Paschalis et al., 2014), namely DYASTIMA. Our predictions are afterwards compared to other estimations derived from previous studies. The current method is furthermore proposed as a paradigm for studying cosmic rays-atmosphere interactions in all terrestrial planets possessing atmospheres.
11	Plasma-moon interactions at Ganymede: a key scientific target for JUICE	Plainaki, C et al.	e-Poster
	Christina Plainaki, Anna Milillo, Stefano Massetti, Alessandro Mura, Stefano Orsini
	INAF - IAPS Via del Fosso del Cavaliere, 00133 Roma, Italy
	The exosphere of Jupiter's moon Ganymede is a mixture of different species namely sputtered-H2O; H2 and O2, formed mainly through radiolysis of ice and subsequent re-combination of the water-dissociation products; and some minor components. Given the variable environment conditions (i.e. iogenic plasma, UV, surface heating etc.) at the Galilean moons, the exosphere of Ganymede results to be spatially and temporally non-uniform hence providing a direct evidence of space weather phenomena in the Jupiter system. The major agent for these effects is the magnetospheric plasma variability, in time and in space. In order to describe the spatial distribution of the H2O and O2 exospheric densities around Ganymede, and to speculate on their possible variations due to space weather, we use the EGEON model (Plainaki et al., Icarus, 2015). In this exospheric model, firstly the plasma entry and circulation inside Ganymede’s magnetosphere, using the global MHD model of Ganymede’s magnetosphere (Jia et al., 2009), is simulated. Then, a 3D Monte Carlo particle model that for the first time takes into consideration the inhomogeneity of the plasma impact on the surface of Ganymede -determined by the morphology of the moon’s intrinsic magnetic field- is applied. We discuss the results of our model in the context of the future ESA/JUICE mission and of its potential to monitor space weather in the Jupiter system. While the JUICE payload elements have the potential to assess space weather phenomena, the highly dynamical nature of the involved processes, require a coordinated approach in order to properly interpret the JUICE data correlation in a vast extent and interpret the phenomena in detail. In this paper we discuss the planning of accurate synergies aiming at determining the dynamic exosphere configuration in space and energy, at Ganymede, as a proxy for space weather phenomena at this satellite.
12	Estimation of the efficiency of different space weather processes at Jupiter's moon Europa	Lucchetti, A et al.	e-Poster
	Alice Lucchetti[1,2], Christina Plainaki[3], Gabriele Cremonese[2], Anna Milillo[3], Timothy Cassidy[4], Xinazhe Jia[5], Valery Shematovich[6]
	[1] CISAS, University of Padova, Via Venezia 15, 35131 Padova, Italy; [2] INAF-Astronomical Observatory of Padova, Vicolo dell’Osservatorio 5, 35131 Padova, Italy; [3] INAF-IAPS Roma, Istituto di Astrofisica e Planetologia Spaziali di Roma, Via del Fosso del Cavaliere, 00133 Roma, Italy; [4] University of Colorado, Laboratory for Atmospheric and Space Physics, 1234 Discovery Drive Boulder, CO 80303, USA; [5] Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, Ann Arbor, MI, USA; [6] Institute of Astronomy RAS, Moscow, Russia.
	Reactions in Europa's exosphere are dominated by plasma interactions with neutrals. The cross-sections for these processes are energy dependent and therefore the respective loss rates of the exospheric species depend on the speed distribution of the charged particles relative to the neutrals, as well as on the densities of each reactant. In this work we perform a detailed estimation of the $H_2O$, $O_2$, and $H_2$ loss rates due to plasma-neutral interactions and we calculate the total mass loss from the moon. Since the plasma electron density at Europa's orbit varies significantly with magnetic latitude, the dissociation and ionization rates due to electron-impact processes are subject to spatial and temporal variations hence the resulting exosphere loss is not homogeneous. In our analysis we discuss the expected spatial variability of Europa's exosphere loss rate and we discuss its potential impact on the spatial distribution of the neutral population density. In addition, the interactions between the planetary ions and the neutral populations have a role in both the loss of exospheric species as well as the modification of the energy distribution of the existing species. In our calculations, we also include photoreactions for both cases of quiet and active Sun. Finally we discuss the current results in the context of future in situ measurements during the ESA's JUICE mission.
13	Definition of Environment Specifications for the Asteroid Impact Mission	Cipriani, F et al.	e-Poster
	Fabrice Cipriani[1], Andrés Galvez[2], Alain Hilgers[1], Ian Carnelli[2], Eamonn Daly[1], Sebastien Hess[3], Pierre Sarraihl[3], Jean-Charles Matéo-Vélez[3]
	[1] ESTEC/TEC-EES; [2] ESA HQ; [3] ONERA/DESP
	The Asteroid Impact and Deflection Assessment mission (AIDA) is a joint European-US technology demonstrator mission including the DART asteroid impactor component (NASA/JHU/APL) and the AIM asteroid rendezvous component (ESA/DLR/OCA). Besides technology demonstration aspects the rendezvous of the AIM platform with Near Earth binary Object 65803 Didymos in October 2022 will allow in situ characterization of the binary asteroid addressing some fundamental science questions. Interestingly, the MASCOT-2 lander will operate in the near surface environment of the binary moonlet, which, together with the potential ability of the Cubesat Opportunity Payloads (COPINS) to sample the dust environment of the binary, will help to better characterize processes of dust charging and transport at airless bodies. In this context, we provide a preliminary assessment of environmental (namely radiation and charged dusts) related risks for the lander and sensitive elements of the orbiting platforms. Such assessment is based on : 1) Radiation environment (fluence and dose) specifications for the cruise phase, total mission and surface phase related to the MASCOT-2 lander operation. 2) An estimation of the electrostatic surface potentials distribution of Didymos moonlet, 170m in diameter, resulting from its interaction with solar wind plasma and solar photons, and of the charging levels, mobilization and transport characteristics of regolith grains. In particular, a range of dust density profiles, m/q, and velocities is provided up to 70m above the surface, based on the currently assumed physical properties of the asteroid regolith, solar illumination conditions at Didymos orbit, and the probability of charged dust to be lifted from the surface. A careful assessment is made on dust grains lifetime since radiation pressure forces largely dominates for grain sizes typically below 5 microns.
14	Space weather effects on the induced magnetospheres of Venus, Mars and the comet CG	Opitz, A et al.	e-Poster
	Andrea Opitz, Karoly Szego, Zoltan Nemeth, Melinda Dosa
	Wigner Research Centre for Physics, Department of Space Physics and Technology, Budapest, Hungary
	Space weather phenomena and their magnitude depend on several factors, among them the heliocentric distance is an important one. We study the solar wind propagation to different distances from the Sun using multi-spacecraft plasma measurements. The solar wind interaction with the ionosphere of such initially unmagnetized bodies forms the induced magnetosphere. This plasma environment of Venus, Mars and the comet CG is highly dependent on the solar wind variations, restructuring can happen on the minute-scale.
15	Updating reaction rates in the context of planetary space weather	Cessateur, G et al.	e-Poster
	Gaël Cessateur[1], Jerome Loreau[2], Johan de Keyser[1], Nathalie Vaeck[2], Romain Maggiolo[1], Frederik Dhooghe[1], Andrew Gibbons[1], Xavier Urbain[3], Pascal Quinet[4], Patrick Palmeri[4]
	[1] Belgian Institute for Space Aeronomy, BIRA-IASB, Brussels, Belgium; [2] Quantum Chemistry and Photophysics Laboratory, Université Libre de Bruxelles, Brussels, Belgium; [3] IMCN/NAPS,Université Catholique de Louvain, Belgium; [4] Astrophysique et Spectroscopie, Université de Mons, Belgium
	In the frame of upper planetary and cometary atmospheres studies, photo rate coefficients for atomic and molecular species are key inputs for photochemical modelling. We present here a sensitivity study of the reaction rates for photo-reactions involving several atmospheric species encountered in cometary and icy moons atmospheres. We will first update the value of the reaction rates regarding the solar activity, from transient events such as flares to long term cycles as the 11-year modulation. Since the amplitude of the variability is cycle-dependent, an update is mandatory to perform accurate modelling in a space weather context. Through several case studies, namely typical neutral cometary and icy moons atmospheres, we will show that the photo rate coefficients can not be taken as a constant along the line of sight. Photochemical models rely generally on a constant rate coefficient which could lead to an overestimation in terms of airglow emissions. This could have some deep impacts regarding planetary atmospheres modelling. We will also show that, for some processes, uncertainties on the reaction cross sections can lead to large errors on the concentration of neutral species.
16	Study of magnetic coupling between Europa's induced field and surrounding plasma currents field.	Agudelo, J et al.	p-Poster
	J. Agudelo
	Universidad de los Andes
	In this work, we present a study of magnetic coupling between Europa's induced magnetic field and its neighboring plasma current fields. This study is relevant for exploring the possibility of liquid water under this moon's ice surface. The magnetometer measurements recovered from the Galileo mission orbitng Europa, shows a magnetic field that does not appear to have an internal source origin. Nevertheles, it has a signature which corresponds to an induced eld produced by a time-variable magnetic field. The model from M. Kivelson (Kivelson et al 2000), suggests that the induced eld is dipolar, but recent studies (A.Pe~na, 2013) shows that one spherical ocean layer in the presence of a time-variable external field, which would be expected if there is liquid water under Europa's ice surface, has a multipolar response. In agreement with these findings, we explore coupling the magnetic field from plasma currents neighbouring Europa to the previous model using the program Magnetic Inner Core (MagIC). We vary the non-dimensional numbers magnetic prandtl (Pm) and Ekman (Ek), to obtain the coupled behaviour of these both magnetic fields and finally contrast the resuts obtained against the Galileo data.