Search

Your search keyword '"Gérard, J.‐C."' showing total 760 results
Start Over Author "Gérard, J.‐C."
760 results on '"Gérard, J.‐C."'

1. Effect of magnetospheric conditions on the morphology of Jupiter's UV main auroral emission, as observed by Juno-UVS

Author

Head, L. A., Grodent, D., Bonfond, B., Moirano, A., Benmahi, B., Sicorello, G., Gérard, J-C, Vogt, M. F., Hue, V., Greathouse, T., Gladstone, G. R., and Yao, Z.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Space Physics
Abstract

Auroral emissions are a reflection of magnetospheric processes, and, at Jupiter, it is not entirely certain how the morphology of the UV main emission (ME) varies with magnetospheric compression or the strength of the central current sheet. This work leverages the observations from Juno-UVS to link ME variability with magnetospheric states. Novel arc-detection techniques are used to determine new reference ovals for the ME from perijoves 1 through 54, in both hemispheres, and analyse how the size and shape of the ME vary compared to this reference oval. The morphology and brightness of the ME vary in local time: the dawn-side ME is typically expanded and the dusk-side ME typically contracted compared to the reference oval, and the dusk-side ME being typically twice as bright as the dawn-side ME. Both the northern and southern ME, and the day-side and night-side ME, expand and contract from their reference ovals synchronously, which indicates that the variable size of the ME is caused by a process occurring throughout the jovian magnetosphere. The poleward latitudinal shift of the auroral footprint of Ganymede correlates with the poleward motion of the ME, whereas a similar relation is not present for the footprint of Io. Additionally, the expansion of the ME correlates well with an increase in magnetodisc current. These two results suggest that a changing current-sheet magnetic field is partially responsible for the variable size of the ME. Finally, magnetospheric compression is linked to a global ME contraction and brightening, though this brightening occurs predominantly in the day-side ME. This observation, and the observation that the dusk-side ME is typically brighter than the dawn-side ME, stands in contrast to the modelled and observed behaviour of field-aligned currents and thus weakens the theoretical link between field-aligned currents and the generation of the auroral ME.

Published
2024
Full Text
View/download PDF

3. Moons and Jupiter Imaging Spectrometer (MAJIS) on Jupiter Icy Moons Explorer (JUICE)

Author

Poulet, F., Piccioni, G., Langevin, Y., Dumesnil, C., Tommasi, L., Carlier, V., Filacchione, G., Amoroso, M., Arondel, A., D’Aversa, E., Barbis, A., Bini, A., Bolsée, D., Bousquet, P., Caprini, C., Carter, J., Dubois, J.-P., Condamin, M., Couturier, S., Dassas, K., Dexet, M., Fletcher, L., Grassi, D., Guerri, I., Haffoud, P., Larigauderie, C., Le Du, M., Mugnuolo, R., Pilato, G., Rossi, M., Stefani, S., Tosi, F., Vincendon, M., Zambelli, M., Arnold, G., Bibring, J.-P., Biondi, D., Boccaccini, A., Brunetto, R., Carapelle, A., Cisneros González, M., Hannou, C., Karatekin, O., Le Cle’ch, J.-C., Leyrat, C., Migliorini, A., Nathues, A., Rodriguez, S., Saggin, B., Sanchez-Lavega, A., Schmitt, B., Seignovert, B., Sordini, R., Stephan, K., Tobie, G., Zambon, F., Adriani, A., Altieri, F., Bockelée, D., Capaccioni, F., De Angelis, S., De Sanctis, M.-C., Drossart, P., Fouchet, T., Gérard, J.-C., Grodent, D., Ignatiev, N., Irwin, P., Ligier, N., Manaud, N., Mangold, N., Mura, A., Pilorget, C., Quirico, E., Renotte, E., Strazzulla, G., Turrini, D., Vandaele, A.-C., Carli, C., Ciarniello, M., Guerlet, S., Lellouch, E., Mancarella, F., Morbidelli, A., Le Mouélic, S., Raponi, A., Sindoni, G., and Snels, M.

Published
2024
Full Text
View/download PDF

4. Discrete Aurora at Mars: Dependence on Upstream Solar Wind Conditions

Author

Girazian, Z, Schneider, NM, Milby, Z, Fang, X, Halekas, J, Weber, T, Jain, SK, Gérard, J‐C, Soret, L, Deighan, J, and Lee, CO

Subjects
Earth Sciences, Atmospheric Sciences, Astronomical Sciences, Physical Sciences, aurora, Mars, discrete aurora, solar wind, Astronomical and Space Sciences, Geophysics, Astronomical sciences, Space sciences
Abstract

Discrete aurora at Mars, characterized by their small spatial scale and tendency to form near strong crustal magnetic fields, are emissions produced by particle precipitation into the Martian upper atmosphere. Since 2014, Mars Atmosphere and Volatile EvolutioN's (MAVEN's) Imaging Ultraviolet Spectrograph (IUVS) has obtained a large collection of UV discrete aurora observations during its routine periapsis nightside limb scans. Initial analysis of these observations has shown that, near the strongest crustal magnetic fields in the southern hemisphere, the IUVS discrete aurora detection frequency is highly sensitive to the interplanetary magnetic field (IMF) clock angle. However, the role of other solar wind properties in controlling the discrete aurora detection frequency has not yet been determined. In this work, we use the IUVS discrete aurora observations, along with MAVEN observations of the upstream solar wind, to determine how the discrete aurora detection frequency varies with solar wind dynamic pressure, IMF strength, and IMF cone angle. We find that, outside of the strong crustal field region (SCFR) in the southern hemisphere, the aurora detection frequency is relatively insensitive to the IMF orientation, but significantly increases with solar wind dynamic pressure, and moderately increases with IMF strength. Interestingly however, although high solar wind dynamic pressures cause more aurora to form, they have little impact on the brightness of the auroral emissions. Alternatively, inside the SCFR, the detection frequency is only moderately dependent on the solar wind dynamic pressure, and is much more sensitive to the IMF clock and cone angles. In the SCFR, aurora are unlikely to occur when the IMF points near the radial or anti-radial directions when the cone angle (arccos(B x /|B|)) is less than 30° or between 120° and 150°. Together, these results provide the first comprehensive characterization of how upstream solar wind conditions affect the formation of discrete aurora at Mars.

Published
2022

6. First ICON‐FUV Nighttime NmF2 and hmF2 Comparison to Ground and Space‐Based Measurements

Author

Wautelet, G, Hubert, B, Gérard, J‐C, Immel, TJ, Frey, HU, Mende, SB, Kamalabadi, F, Kamaci, U, and England, SL

Subjects
Earth Sciences, Atmospheric Sciences, Physical Sciences, airglow, ICON, FUV, GNSS, ionosonde, comparison, Astronomical and Space Sciences, Geophysics, Astronomical sciences, Space sciences
Abstract

The Far Ultra Violet (FUV) ultraviolet imager onboard the NASA-ICON mission is dedicated to the observation and study of the ionosphere dynamics at mid and low latitudes. We compare O+ density profiles provided by the ICON FUV instrument during nighttime with electron density profiles measured by the COSMIC-2 constellation (C2) and ground-based ionosondes. Co-located simultaneous observations are compared, covering the period from November 2019 to July 2020, which produces several thousands of coincidences. Manual scaling of ionogram sequences ensures the reliability of the ionosonde profiles, while C2 data are carefully selected using an automatic quality control algorithm. Photoelectron contribution coming from the magnetically conjugated hemisphere is clearly visible in FUV data around solstices and has been filtered out from our analysis. We find that the FUV observations are consistent with the C2 and ionosonde measurements, with an average positive bias lower than 1 × 1011e/m3. When restricting the analysis to cases having an NmF2 value larger than 5 × 1011e/m3, FUV provides the peak electron density with a mean difference with C2 of 10%. The peak altitude, also determined from FUV observations, is found to be 15 km above that obtained from C2, and 38 km above the ionosonde value on average.

Published
2021

10. Corotating Magnetic Reconnection Site in Saturn's Magnetosphere

Author

Yao, Zhonghua, Coates, A. J., Ray, L. C., Rae, I. J., Grodent, D., Jones, G. H., Dougherty, M. K., Owen, C. J., Guo, R. L., Dunn, W., Radioti, A., Pu, Z. Y., Lewis, G. R., Waite, J. H., and Gerard, J. -C.

Subjects
Physics - Space Physics
Abstract

Using measurements from the Cassini spacecraft in Saturn's magnetosphere, we propose a 3D physical picture of a corotating reconnection site, which can only be driven by an internally generated source. Our results demonstrate that the corotating magnetic reconnection can drive an expansion of the current sheet in Saturn's magnetosphere and, consequently, can produce Fermi acceleration of electrons. This reconnection site lasted for longer than one of Saturn's rotation period. The long-lasting and corotating natures of the magnetic reconnection site at Saturn suggest fundamentally different roles of magnetic reconnection in driving magnetospheric dynamics (e.g., the auroral precipitation) from the Earth. Our corotating reconnection picture could also potentially shed light on the fast rotating magnetized plasma environments in the solar system and beyond., Comment: 7 pages, 5 figures

Published
2017
Full Text
View/download PDF

11. The Ionospheric Connection Explorer Mission: Mission Goals and Design

Author

Immel, TJ, England, SL, Mende, SB, Heelis, RA, Englert, CR, Edelstein, J, Frey, HU, Korpela, EJ, Taylor, ER, Craig, WW, Harris, SE, Bester, M, Bust, GS, Crowley, G, Forbes, JM, Gérard, J-C, Harlander, JM, Huba, JD, Hubert, B, Kamalabadi, F, Makela, JJ, Maute, AI, Meier, RR, Raftery, C, Rochus, P, Siegmund, OHW, Stephan, AW, Swenson, GR, Frey, S, Hysell, DL, Saito, A, Rider, KA, and Sirk, MM

Subjects
Space Sciences, Astronomical Sciences, Physical Sciences, Aeronomy, Ionospheres, Thermospheres, Ion-Neutral Interactions, Atmospheric Waves, Geospace, Astronomical and Space Sciences, Astronomy & Astrophysics, Astronomical sciences, Space sciences
Abstract

The Ionospheric Connection Explorer, or ICON, is a new NASA Explorer mission that will explore the boundary between Earth and space to understand the physical connection between our world and our space environment. This connection is made in the ionosphere, which has long been known to exhibit variability associated with the sun and solar wind. However, it has been recognized in the 21st century that equally significant changes in ionospheric conditions are apparently associated with energy and momentum propagating upward from our own atmosphere. ICON's goal is to weigh the competing impacts of these two drivers as they influence our space environment. Here we describe the specific science objectives that address this goal, as well as the means by which they will be achieved. The instruments selected, the overall performance requirements of the science payload and the operational requirements are also described. ICON's development began in 2013 and the mission is on track for launch in 2017. ICON is developed and managed by the Space Sciences Laboratory at the University of California, Berkeley, with key contributions from several partner institutions.

Published
2018

13. The EChO science case

Author

Tinetti, Giovanna, Drossart, Pierre, Eccleston, Paul, Hartogh, Paul, Isaak, Kate, Linder, Martin, Lovis, Christophe, Micela, Giusi, Ollivier, Marc, Puig, Ludovic, Ribas, Ignasi, Snellen, Ignas, Allard, Bruce Swinyard. France, Barstow, Joanna, Cho, James, Coustenis, Athena, Cockell, Charles, Correia, Alexandre, Decin, Leen, de Kok, Remco, Deroo, Pieter, Encrenaz, Therese, Forget, Francois, Glasse, Alistair, Griffith, Caitlin, Guillot, Tristan, Koskinen, Tommi, Lammer, Helmut, Leconte, Jeremy, Maxted, Pierre, Mueller-Wodarg, Ingo, Nelson, Richard, North, Chris, Pallé, Enric, Pagano, Isabella, Piccioni, Guseppe, Pinfield, David, Selsis, Franck, Sozzetti, Alessandro, Stixrude, Lars, Tennyson, Jonathan, Turrini, Diego, Beaulieu, Mariarosa Zapatero-Osorio. Jean-Philippe, Grodent, Denis, Guedel, Manuel, Luz, David, Nørgaard-Nielsen, Hans Ulrik, Ray, Tom, Rickman, Hans, Selig, Avri, Banaszkiewicz, Mark Swain. Marek, Barlow, Mike, Bowles, Neil, Branduardi-Raymont, Graziella, Foresto, Vincent Coudé du, Gerard, Jean-Claude, Gizon, Laurent, Hornstrup, Allan, Jarchow, Christopher, Kerschbaum, Franz, Kovacs, Géza, Lagage, Pierre-Olivier, Lim, Tanya, Lopez-Morales, Mercedes, Malaguti, Giuseppe, Pace, Emanuele, Pascale, Enzo, Vandenbussche, Bart, Wright, Gillian, Adriani, Gonzalo Ramos Zapata. Alberto, Azzollini, Ruymán, Balado, Ana, Bryson, Ian, Burston, Raymond, Colomé, Josep, Crook, Martin, Di Giorgio, Anna, Griffin, Matt, Hoogeveen, Ruud, Ottensamer, Roland, Irshad, Ranah, Middleton, Kevin, Morgante, Gianluca, Pinsard, Frederic, Rataj, Mirek, Reess, Jean-Michel, Savini, Giorgio, Schrader, Jan-Rutger, Stamper, Richard, Abe, Berend Winter. L., Abreu, M., Achilleos, N., Ade, P., Adybekian, V., Affer, L., Agnor, C., Agundez, M., Alard, C., Alcala, J., Prieto, C. Allende, Floriano, F. J. Alonso, Altieri, F., Iglesias, C. A. Alvarez, Amado, P., Andersen, A., Aylward, A., Baffa, C., Bakos, G., Ballerini, P., Banaszkiewicz, M., Barber, R. J., Barrado, D., Barton, E. J., Batista, V., Bellucci, G., Avilés, J. A. Belmonte, Berry, D., Bézard, B., Biondi, D., Błęcka, M., Boisse, I., Bonfond, B., Bordé, P., Börner, P., Bouy, H., Brown, L., Buchhave, L., Budaj, J., Bulgarelli, A., Burleigh, M., Cabral, A., Capria, M. T., Cassan, A., Cavarroc, C., Cecchi-Pestellini, C., Cerulli, R., Chadney, J., Chamberlain, S., Charnoz, S., Jessen, N. Christian, Ciaravella, A., Claret, A., Claudi, R., Coates, A., Cole, R., Collura, A., Cordier, D., Covino, E., Danielski, C., Damasso, M., Deeg, H. J., Delgado-Mena, E., Del Vecchio, C., Demangeon, O., De Sio, A., De Wit, J., Dobrijévic, M., Doel, P., Dominic, C., Dorfi, E., Eales, S., Eiroa, C., Contreras, M. Espinoza, Esposito, M., Eymet, V., Fabrizio, N., Fernández, M., Castella, B. Femenía, Figueira, P., Filacchione, G., Fletcher, L., Focardi, M., Fossey, S., Fouqué, P., Frith, J., Galand, M., Gambicorti, L., Gaulme, P., López, R. J. García, Garcia-Piquer, A., Gear, W., Gerard, J. -C., Gesa, L., Giani, E., Gianotti, F., Gillon, M., Giro, E., Giuranna, M., Gomez, H., Gomez-Leal, I., Hernandez, J. Gonzalez, Merino, B. González, Graczyk, R., Grassi, D., Guardia, J., Guio, P., Gustin, J., Hargrave, P., Haigh, J., Hébrard, E., Heiter, U., Heredero, R. L., Herrero, E., Hersant, F., Heyrovsky, D., Hollis, M., Hubert, B., Hueso, R., Israelian, G., Iro, N., Irwin, P., Jacquemoud, S., Jones, G., Jones, H., Justtanont, K., Kehoe, T., Kerschbaum, F., Kerins, E., Kervella, P., Kipping, D., Koskinen, T., Krupp, N., Lahav, O., Laken, B., Lanza, N., Lellouch, E., Leto, G., Goldaracena, J. Licandro, Lithgow-Bertelloni, C., Liu, S. J., Cicero, U. Lo, Lodieu, N., Lognonné, P., Lopez-Puertas, M., Lopez-Valverde, M. A., Rasmussen, I. Lundgaard, Luntzer, A., Machado, P., MacTavish, C., Maggio, A., Maillard, J. -P., Magnes, W., Maldonado, J., Mall, U., Marquette, J. -B., Mauskopf, P., Massi, F., Maurin, A. -S., Medvedev, A., Michaut, C., Miles-Paez, P., Montalto, M., Rodríguez, P. Montañés, Monteiro, M., Montes, D., Morais, H., Morales, J. C., Morales-Calderón, M., Morello, G., Martín, A. Moro, Moses, J., Bedon, A. Moya, Alcaino, F. Murgas, Oliva, E., Orton, G., Palla, F., Pancrazzi, M., Pantin, E., Parmentier, V., Parviainen, H., Ramírez, K. Y. Peña, Peralta, J., Perez-Hoyos, S., Petrov, R., Pezzuto, S., Pietrzak, R., Pilat-Lohinger, E., Piskunov, N., Prinja, R., Prisinzano, L., Polichtchouk, I., Poretti, E., Radioti, A., Ramos, A. A., Rank-Lüftinger, T., Read, P., Readorn, K., López, R. Rebolo, Rebordão, J., Rengel, M., Rezac, L., Rocchetto, M., Rodler, F., Béjar, V. J. Sánchez, Lavega, A. Sanchez, Sanromá, E., Santos, N., Forcada, J. Sanz, Scandariato, G., Schmider, F. -X., Scholz, A., Scuderi, S., Sethenadh, J., Shore, S., Showman, A., Sicardy, B., Sitek, P., Smith, A., Soret, L., Sousa, S., Stiepen, A., Stolarski, M., Strazzulla, G., Tabernero, H. M, Tanga, P., Tecsa, M., Temple, J., Terenzi, L., Tessenyi, M., Testi, L., Thompson, S., Thrastarson, H., Tingley, B. W., Trifoglio, M., Torres, J. Martín, Tozzi, A., Turrini, D., Varley, R., Vakili, F., de Val-Borro, M., Valdivieso, M. L., Venot, O., Villaver, E., Vinatier, S., Viti, S., Waldmann, I., Waltham, D., Ward-Thompson, D., Waters, R., Watkins, C., Watson, D., Wawer, P., Wawrzaszk, A., White, G., Widemann, T., Winek, W., Wiśniowski, T., Yelle, R., Yung, Y., and Yurchenko, S. N.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The discovery of almost 2000 exoplanets has revealed an unexpectedly diverse planet population. Observations to date have shown that our Solar System is certainly not representative of the general population of planets in our Milky Way. The key science questions that urgently need addressing are therefore: What are exoplanets made of? Why are planets as they are? What causes the exceptional diversity observed as compared to the Solar System? EChO (Exoplanet Characterisation Observatory) has been designed as a dedicated survey mission for transit and eclipse spectroscopy capable of observing a large and diverse planet sample within its four-year mission lifetime. EChO can target the atmospheres of super-Earths, Neptune-like, and Jupiter-like planets, in the very hot to temperate zones (planet temperatures of 300K-3000K) of F to M-type host stars. Over the next ten years, several new ground- and space-based transit surveys will come on-line (e.g. NGTS, CHEOPS, TESS, PLATO), which will specifically focus on finding bright, nearby systems. The current rapid rate of discovery would allow the target list to be further optimised in the years prior to EChO's launch and enable the atmospheric characterisation of hundreds of planets. Placing the satellite at L2 provides a cold and stable thermal environment, as well as a large field of regard to allow efficient time-critical observation of targets randomly distributed over the sky. A 1m class telescope is sufficiently large to achieve the necessary spectro-photometric precision. The spectral coverage (0.5-11 micron, goal 16 micron) and SNR to be achieved by EChO, thanks to its high stability and dedicated design, would enable a very accurate measurement of the atmospheric composition and structure of hundreds of exoplanets., Comment: 50 pages, 30 figures. Experimental Astronomy

Published
2015
Full Text
View/download PDF

20. Juno observations of spot structures and a split tail in Io-induced aurorae on Jupiter

Author

Mura, A., Adriani, A., Connerney, J. E. P., Bolton, S., Altieri, F., Bagenal, F., Bonfond, B., Dinelli, B. M., Gérard, J.-C., Greathouse, T., Grodent, D., Levin, S., Mauk, B., Moriconi, M. L., Saur, J., Waite, J. H., Amoroso, M., Cicchetti, A., Fabiano, F., Filacchione, G., Grassi, D., Migliorini, A., Noschese, R., Olivieri, A., Piccioni, G., Plainaki, C., Sindoni, G., Sordini, R., Tosi, F., and Turrini, D.

Published
2018

25. Variability of the Auroral Footprint of Io Detected by Juno‐JIRAM and Modeling of the Io Plasma Torus

Author

Moirano, A., primary, Mura, A., additional, Bonfond, B., additional, Connerney, J. E. P., additional, Dols, V., additional, Grodent, D., additional, Hue, V., additional, Gérard, J.‐C., additional, Tosi, F., additional, Migliorini, A., additional, Adriani, A., additional, Altieri, F., additional, Castagnoli, C., additional, Cicchetti, A., additional, Dinelli, B. M., additional, Grassi, D., additional, Moriconi, M. L., additional, Noschese, R., additional, Piccioni, G., additional, Plainaki, C., additional, Scarica, P., additional, Sindoni, G., additional, Sordini, R., additional, Turrini, D., additional, and Zambon, F., additional

Published
2023
Full Text
View/download PDF

26. Juno's Multi‐Instruments Observations During the Flybys of Auroral Bright Spots in Jupiter's Polar Aurorae

Author

Haewsantati, K., primary, Bonfond, B., additional, Wannawichian, S., additional, Gladstone, G. R., additional, Hue, V., additional, Greathouse, T. K., additional, Grodent, D., additional, Yao, Z., additional, Gérard, J.‐C., additional, Guo, R., additional, Elliott, S., additional, Mauk, B. H., additional, Clark, G., additional, Gershman, D., additional, Kotsiaros, S., additional, Kurth, W. S., additional, Connerney, J., additional, Szalay, J. R., additional, and Phriksee, A., additional

Published
2023
Full Text
View/download PDF

27. SPICAM on Mars Express: A 10 year in-depth survey of the Martian atmosphere

Author

Montmessin, F., Korablev, O., Lefèvre, F., Bertaux, J.-L., Fedorova, A., Trokhimovskiy, A., Chaufray, J.Y., Lacombe, G., Reberac, A., Maltagliati, L., Willame, Y., Guslyakova, S., Gérard, J.-C., Stiepen, A., Fussen, D., Mateshvili, N., Määttänen, A., Forget, F., Witasse, O., Leblanc, F., Vandaele, A.C., Marcq, E., Sandel, B., Gondet, B., Schneider, N., Chaffin, M., and Chapron, N.

Published
2017
Full Text
View/download PDF

32. Discrete Aurora at Mars: Insights Into the Role of Magnetic Reconnection.

Author

Johnston, B. J., Schneider, N. M., Jain, S. K., Milby, Z., Deighan, J., Bowers, C. F., DiBraccio, G. A., Gérard, J.‐C., Soret, L., Girazian, Z., Brain, D. A., Ruhunusiri, S., and Curry, S.

Subjects
MAGNETIC reconnection, SOLAR magnetic fields, GEOMAGNETISM, MARTIAN atmosphere, AURORAS, SOLAR wind, MARS (Planet)
Abstract

Discrete aurora are sporadic emissions of light originating in Mars upper atmosphere. We report nadir imaging observations from MAVEN's Imaging UltraViolet Spectrograph which identify the conditions which trigger electron precipitation causing these events. Prior studies have shown that discrete aurora events in the strong crustal magnetic field region in the southern hemisphere are the brightest and most repeatable compared to events occurring outside the region. Our new data set offers a more complete and accurate characterization of aurora in this area. The region of strongest crustal fields is composed of two distinct magnetic regions, with magnetic fields in opposite directions; discrete aurora events trigger in one region after dusk and in the other before dawn. Magnetic reconnection in these two adjacent regions with the draped interplanetary field may open the crustal fields in these regions during opposing local times. Particle precipitation can then cause discrete aurora at the observed times and locations. Plain Language Summary: Mars has a surprising variety of types of aurora, all different from Earth's "northern lights." Mars lacks the familiar high‐latitude aurora because it no longer has the same kind of global magnetic field Earth does. This study examines "discrete aurora" events that occur in region in Mars southern hemisphere that has retained some of the ancient magnetic field. It takes the form of long arcades of magnetic loops that resemble a set of arches. As Mars rotates, these arcades are carried around the planet as the solar wind and its imbedded magnetic field are carried past the planet. We show that when conditions are favorable, the magnetic field locked in the solar wind can interact and "reconnect" with Mars magnetic loops, allowing energetic particles to spiral down the field lines into the atmosphere to cause discrete aurora. Key Points: New data confirm that Mars discrete aurora events occur most frequently near strong crustal fields and vary with local timeAuroral events in adjacent regions with opposite magnetic polarity occur before or after midnight depending on local magnetic field directionMagnetic reconnection between crustal fields and the draped interplanetary field appears to control regional and local time behavior [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

34. The Io, Europa, and Ganymede Auroral Footprints at Jupiter in the Ultraviolet: Positions and Equatorial Lead Angles

Author

Hue, V., primary, Gladstone, G. R., additional, Louis, C. K., additional, Greathouse, T. K., additional, Bonfond, B., additional, Szalay, J. R., additional, Moirano, A., additional, Giles, R. S., additional, Kammer, J. A., additional, Imai, M., additional, Mura, A., additional, Versteeg, M. H., additional, Clark, G., additional, Gérard, J.‐C., additional, Grodent, D. C., additional, Rabia, J., additional, Sulaiman, A. H., additional, Bolton, S. J., additional, and Connerney, J. E. P., additional

Published
2023
Full Text
View/download PDF

35. Juno's Multi-Instruments Observations During the Flybys of Auroral Bright Spots in Jupiter's Polar Aurorae

Author

Haewsantati, K., Bonfond, B., Wannawichian, S., Gladstone, G. R., Hue, V., Greathouse, T. K., Grodent, D., Yao, Z., Gérard, J. C., Guo, R., Elliott, S., Mauk, B. H., Clark, G., Gershman, D., Kotsiaros, S., Kurth, W. S., Connerney, J., Szalay, J. R., Phriksee, A., Haewsantati, K., Bonfond, B., Wannawichian, S., Gladstone, G. R., Hue, V., Greathouse, T. K., Grodent, D., Yao, Z., Gérard, J. C., Guo, R., Elliott, S., Mauk, B. H., Clark, G., Gershman, D., Kotsiaros, S., Kurth, W. S., Connerney, J., Szalay, J. R., and Phriksee, A.

Abstract

Juno's arrival at Jupiter in 2016 revealed unprecedented details about Jupiter's ultraviolet aurorae thanks to its unique suite of remote sensing and in situ instruments. Here we present results from in situ observations during Juno flybys above specific bright auroral spots in Jupiter's polar aurora. We compare data observed by Juno-UVS, JEDI, JADE, Waves, and MAG instruments when Juno was magnetically connected to bright polar auroral spots (or their immediate vicinity) during perijove 3 (PJ3), PJ15, and PJ33. The highly energetic particles observed by JEDI show enhancements dominated by upward electrons, which suggests that the particle acceleration region takes place below the spacecraft. Moreover, brightness and upward particle flux were higher for the northern bright spot in PJ3 than the southern spots found in PJ15 and PJ33. In addition, we notice the intensification of whistler-mode waves at the time of the particle enhancements, suggesting that wave-particle interactions contribute to the acceleration of particles that cause the UV aurorae. The MAG data reveal magnetic perturbations during the PJ3 spot detection by Juno, which suggests the presence of significant field-aligned electric currents. While the stable positions of the bright spots in System III suggest that the phenomenon is fixed to the planet's rotation, the presence of field-aligned currents leaves the possibility of an origin rooted much farther in the magnetosphere.

Published
2023

39. Ganymede's UV Reflectance From Juno‐UVS Data

Author

Molyneux, P. M., primary, Greathouse, T. K., additional, Gladstone, G. R., additional, Versteeg, M. H., additional, Hue, V., additional, Kammer, J., additional, Davis, M. W., additional, Bolton, S. J., additional, Giles, R., additional, Connerney, J. E. P., additional, Gérard, J. C., additional, and Grodent, D. C., additional

Published
2022
Full Text
View/download PDF

42. Magnetosphere‐Ionosphere‐Thermosphere Coupling Study at Jupiter Based on Juno's First 30 Orbits and Modeling Tools

Author

Al Saati, S., primary, Clément, N., additional, Louis, C., additional, Blanc, M., additional, Wang, Y., additional, André, N., additional, Lamy, L., additional, Bonfond, B., additional, Collet, B., additional, Allegrini, F., additional, Bolton, S., additional, Clark, G., additional, Connerney, J. E. P., additional, Gérard, J.‐C., additional, Gladstone, G. R., additional, Kotsiaros, S., additional, Kurth, W. S., additional, and Mauk, B., additional

Published
2022
Full Text
View/download PDF

45. NOMAD, an Integrated Suite of Three Spectrometers for the ExoMars Trace Gas Mission: Technical Description, Science Objectives and Expected Performance

Author

Vandaele, A. C., Lopez-Moreno, J.-J., Patel, M. R., Bellucci, G., Daerden, F., Ristic, B., Robert, S., Thomas, I. R., Wilquet, V., Allen, M., Alonso-Rodrigo, G., Altieri, F., Aoki, S., Bolsée, D., Clancy, T., Cloutis, E., Depiesse, C., Drummond, R., Fedorova, A., Formisano, V., Funke, B., González-Galindo, F., Geminale, A., Gérard, J.-C., Giuranna, M., Hetey, L., Ignatiev, N., Kaminski, J., Karatekin, O., Kasaba, Y., Leese, M., Lefèvre, F., Lewis, S. R., López-Puertas, M., López-Valverde, M., Mahieux, A., Mason, J., McConnell, J., Mumma, M., Neary, L., Neefs, E., Renotte, E., Rodriguez-Gomez, J., Sindoni, G., Smith, M., Stiepen, A., Trokhimovsky, A., Vander Auwera, J., Villanueva, G., Viscardy, S., Whiteway, J., Willame, Y., Wolff, M., and the NOMAD Team

Published
2018
Full Text
View/download PDF

46. Planet‐Wide Ozone Destruction in the Middle Atmosphere on Mars During Global Dust Storm

Author

Daerden, F., Neary, L., Wolff, M. J., Clancy, R. T., Lefèvre, F., Whiteway, J. A., Viscardy, S., Piccialli, A., Willame, Y., Depiesse, C., Aoki, S., Thomas, I. R., Ristic, B., Erwin, J., Gérard, J.‐C., Sandor, B. J., Khayat, A., Smith, M. D., Mason, J. P., Patel, M. R., Villanueva, G. L., Liuzzi, G., Bellucci, G., Lopez‐Moreno, J.‐J., Vandaele, A. C., Ministerio de Ciencia e Innovación (España), European Commission, Belgian Science Policy Office, and UK Space Agency

Subjects
Ozone, Geophysics, Atmosphere, Mars, NOMAD, General Earth and Planetary Sciences, General circulation model, Global dust storm
Abstract

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes., The Nadir and Occultation for MArs Discovery (NOMAD)/UV-visible (UVIS) spectrometer on the ExoMars Trace Gas Orbiter provided observations of ozone (O3) and water vapor in the global dust storm of 2018. Here we show in detail, using advanced data filtering and chemical modeling, how Martian O3 in the middle atmosphere was destroyed during the dust storm. In data taken exactly 1 year later when no dust storm occurred, the normal situation had been reestablished. The model simulates how water vapor is transported to high altitudes and latitudes in the storm, where it photolyzes to form odd hydrogen species that catalyze O3. O3 destruction is simulated at all latitudes and up to 100 km, except near the surface where it increases. The simulations also predict a strong increase in the photochemical production of atomic hydrogen in the middle atmosphere, consistent with the enhanced hydrogen escape observed in the upper atmosphere during global dust storms. © 2022 The Authors., This work was made possible thanks to the reconstructed gridded maps of column dust optical depth from Mars Climate Sounder observations provided by L. Montabone. The dust maps were prepared using MCS v5.3 provided by A. Kleinböhl and D. Kass. Dust climatologies can be found at the following link: http://www-mars.lmd.jussieu.fr/mars/dust_climatology/. ExoMars is a space mission of the European Space Agency (ESA) and Roscosmos. The NOMAD experiment is led by the Royal Belgian Institute for Space Aeronomy (IASB-BIRA), assisted by Co-PI teams from Spain (IAA-CSIC), Italy (INAF-IAPS), and the United Kingdom (Open University). This project acknowledges funding by the Belgian Science Policy Office (BELSPO), with the financial and contractual coordination by the ESA Prodex Office (PEA 4000103401, 4000121493), by the UK Space Agency (grants ST/V002295/1, ST/P001262/1, ST/V005332/1 and ST/S00145X/1), by the Spanish Ministry of Science and Innovation (MCIU), and by European funds (grants PGC2018-101836-B-I00 and ESP2017-87143-R, MINECO/FEDER), as well as by the Italian Space Agency (Grant 2018-2-HH.0). This work was supported by the Belgian Fonds de la Recherche Scientifique – FNRS (Grant Nos. 30442502, ET_HOME). This work has received funding from the European Union's Horizon 2020 research and innovation programme (grant agreement No 101004052, RoadMap project). The IAA/CSIC team acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). US investigators were supported by the National Aeronautics and Space Administration, by NASA's Mars Program Office (under WBS 604796, “Participation in the TGO/NOMAD Investigation of Trace Gases on Mars.”), and by NASA (award number 80GSFC21M0002). Canadian investigators were supported by the Canadian Space Agency.

Published
2022

47. The Mars Oxygen Visible Dayglow: A Martian Year of NOMAD/UVIS Observations

Author

Soret, L., Gérard, J.‐C., Aoki, S., Gkouvelis, L., Thomas, I. R., Ristic, B., Hubert, B., Willame, Y., Depiesse, C., Vandaele, A.C., Patel, M. R., Mason, J. P., Daerden, F., López‐Moreno, J.‐J., Bellucci, G., Ministerio de Ciencia e Innovación (España), European Commission, Belgian Science Policy Office, UK Space Agency, and Agenzia Spaziale Italiana

Subjects
Oxygen, Green line, Geophysics, Atmosphere, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Mars, Dayglow, Red line
Abstract

The Ultraviolet and Visible Spectrometer Ultraviolet (UVIS UV) and Visible Spectrometer channel of the Nadir and Occultation for MArs Discovery spectrometer aboard the ExoMars Trace Gas Orbiter has made limb observations of the Martian dayglow during more than a Martian year. Two pointing modes have been applied: (a) In the inertial mode, the spectrometer scans the atmosphere twice down to near the surface and provides altitude profiles of the dayglow; (b) in the tracking mode, the atmosphere is scanned at varying latitudes at a nearly constant altitude through the entire observation. We present a statistical study of the vertical and seasonal distribution of the recently discovered oxygen green and red lines at 557.7 nm and 630 nm. It indicates that the brightness of the green line emission responds to changes in the Lyman-α flux. The peak altitude of the green line emission increases seasonally when the Sun-Mars distance decreases. The lower peak of the green line statistically drops by 15–20 km between perihelion and aphelion at mid-to high altitude. The main lower peak intensity shows an asymmetry between the two hemispheres. It is significantly brighter and more pronounced in the southern hemisphere than in the north. This is a consequence of the stronger Lyman-α solar flux near perihelion. The second component of the oxygen red line at 636.4 nm is also detected for the first time in the Martian atmosphere. A photochemical model is used to simulate the variations of the green dayglow observed along limb tracking orbits. © 2022. American Geophysical Union. All Rights Reserved., The NOMAD experiment is led by the Royal Belgian Institute for Space Aeronomy (IASB-BIRA), assisted by Co-PI teams from Spain (IAA-CSIC), Italy (INAF-IAPS), and the United Kingdom (Open University). This project acknowledges funding by the Belgian Science Policy Office (BELSPO), with the financial and contractual coordination by the ESA Prodex Office (PEA 4000103401, 4000121493, 4000129686), by Spanish Ministry of Science and Innovation (MCIU) and by European funds under grants PGC2018-101836-B-I00 and ESP2017-87143-R (MINECO/FEDER), as well as by UK Space Agency. This work is supported by the UK Space Agency through grants ST/V002295/1, ST/V005332/1 and ST/S00145X/1 and Italian Space Agency through Grant 2018-2-HH.0. This research was supported by the Belgian Fonds de la Recherche Scientifique – FNRS under Grant No. 30442502 (ET_HOME). B. H. is supported by FNRS. The IAA/CSIC team acknowledges financial support from the State Agency for Research of the Spanish MCIU through the “Center of Excellence Severo Ochoa” award for the Instituto de Astrofísica de Andalucía (SEV-2017-0709). L. Gkouvelis is supported by the National Aeronautics and Space Administration. B. H. is supported by the Belgian Fund for Scientific Research (FNRS).

Published
2022

48. Scientific problems addressed by the Spektr-UV space project (world space Observatory—Ultraviolet)

Author

Boyarchuk, A. A., Shustov, B. M., Savanov, I. S., Sachkov, M. E., Bisikalo, D. V., Mashonkina, L. I., Wiebe, D. Z., Shematovich, V. I., Shchekinov, Yu. A., Ryabchikova, T. A., Chugai, N. N., Ivanov, P. B., Voshchinnikov, N. V., Gomez de Castro, A. I., Lamzin, S. A., Piskunov, N., Ayres, T., Strassmeier, K. G., Jeffrey, S., Zwintz, S. K., Shulyak, D., Gérard, J.-C., Hubert, B., Fossati, L., Lammer, H., Werner, K., Zhilkin, A. G., Kaigorodov, P. V., Sichevskii, S. G., Ustamuich, S., Kanev, E. N., and Kil’pio, E. Yu.

Published
2016
Full Text
View/download PDF

49. The Ionospheric Connection Explorer Mission: Mission Goals and Design

Author

Immel, T. J., England, S. L., Mende, S. B., Heelis, R. A., Englert, C. R., Edelstein, J., Frey, H. U., Korpela, E. J., Taylor, E. R., Craig, W. W., Harris, S. E., Bester, M., Bust, G. S., Crowley, G., Forbes, J. M., Gérard, J.-C., Harlander, J. M., Huba, J. D., Hubert, B., Kamalabadi, F., Makela, J. J., Maute, A. I., Meier, R. R., Raftery, C., Rochus, P., Siegmund, O. H. W., Stephan, A. W., Swenson, G. R., Frey, S., Hysell, D. L., Saito, A., Rider, K. A., and Sirk, M. M.

Published
2017
Full Text
View/download PDF

50. Planet‐Wide Ozone Destruction in the Middle Atmosphere on Mars During Global Dust Storm

Author

Daerden, F., primary, Neary, L., additional, Wolff, M. J., additional, Clancy, R. T., additional, Lefèvre, F., additional, Whiteway, J. A., additional, Viscardy, S., additional, Piccialli, A., additional, Willame, Y., additional, Depiesse, C., additional, Aoki, S., additional, Thomas, I. R., additional, Ristic, B., additional, Erwin, J., additional, Gérard, J.‐C., additional, Sandor, B. J., additional, Khayat, A., additional, Smith, M. D., additional, Mason, J. P., additional, Patel, M. R., additional, Villanueva, G. L., additional, Liuzzi, G., additional, Bellucci, G., additional, Lopez‐Moreno, J.‐J., additional, and Vandaele, A. C., additional

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results