The Io UV footprint: Location, inter-spot distances and tail vertical extent (2009)
Bonfond, Bertrand, Grodent, Denis, Gérard, Jean-Claude, Radioti, Aikaterini, Dols, Vincent, Delamere, Peter, ...
The Io footprint (IFP) consists of one or several spots observed in both jovian hemispheres and is related to the electromagnetic interaction between Io and the magnetosphere. These spots are...
The Io UV footprint: Location, inter-spot distances and tail vertical extent (2009)
Bonfond, Bertrand, Grodent, Denis, Gérard, Jean-Claude, Radioti, Aikaterini, Dols, V, Delamere, P A, ...
The Io footprint (IFP) consists of one or several spots observed in both jovian hemispheres and is related to the electromagnetic interaction between Io and the magnetosphere. These spots are...
Auroral footprint of Ganymede (2009)
Grodent, Denis, Bonfond, Bertrand, Radioti, Aikaterini, Gérard, Jean-Claude, Jia, Xianzhe, Nichols, Jonathan D, ...
The interaction of Ganymede with Jupiter's fast rotating magnetospheric plasma gives rise to a current system producing an auroral footprint in Jupiter's ionosphere, usually referred to as the...
Variation of different components of Jupiter's auroral emission (2009)
Nichols, J D, Clarke, J T, Gérard, Jean-Claude, Grodent, Denis, Hansen, K C
The Hubble Space Telescope (HST) data set obtained over two campaigns in 2007 is used to determine the long-term variability of the different components of Jupiter's auroras. Three regions on the...
The auroral footprint of Ganymede (2009)
Grodent, Denis, Bonfond, Bertrand, Radioti, Aikaterini, Gérard, Jean-Claude, Jia, Xianzhe, Nichols, Jonathan D., ...
The interaction of Ganymede with Jupiter's fast rotating magnetospheric plasma gives rise to a current system producing an auroral footprint in Jupiter's ionosphere, usually referred to as the...
Radioti, Aikaterini, Tomás, Ana Tomas, Grodent, Denis, Gérard, Jean-Claude, Gustin, Jacques, Bonfond, Bertrand, ...
Abstract Available from http://www.agu.org
Response of Jupiter's and Saturn's auroral activity to the solar wind (2009)
Clarke, J T, Nichols, J, Gérard, Jean-Claude, Grodent, Denis, Hansen, K C, Kurth, William, ...
While the terrestrial aurorae are known to be driven primarily by the interaction of the Earth's magnetosphere with the solar wind, there is considerable evidence that auroral emissions on Jupiter...
Equatorward diffuse auroral emissions at Jupiter: Simultaneous HST and Galileo observations (2009)
Radioti, Aikaterini, Tomás, Ana Teresa, Grodent, Denis, Gérard, Jean-Claude, Gustin, Jacques, Bonford, Bertrand, ...
We study the auroral emissions equatorward of the main oval based on Hubble Space Telescope (HST) observations of both Jovian hemispheres on September 20, 1997. On the same day, Galileo observed...
Observations of Jovian polar auroral filaments (2009)
Nichols, J D, Clarke, J T, Gérard, Jean-Claude, Grodent, Denis
In this paper we report a phenomenon hitherto unobserved in Jupiter's ultraviolet polar auroras, specifically thin (~0.6° wide), long-lived quasi-sun-aligned polar auroral filaments (PAFs) of...
Observations of Jovian polar auroral filaments (2009)
Nichols, J D, Clarke, J T, Gérard, Jean-Claude, Grodent, Denis
In this paper we report a phenomenon hitherto unobserved in Jupiter's ultraviolet polar auroras, specifically thin (~0.6° wide), long-lived quasi-sun-aligned polar auroral filaments (PAFs) of...
Radioti, Aikaterini, Grodent, Denis, Gérard, Jean-Claude, Roussos, Elias, Paranicas, C, Bonfond, Bertrand, ...
We report for the first time transient isolated auroral spots at Saturn's southern polar region, based on Hubble Space Telescope (HST) FUV images. The spots last several minutes and appear distinct...
Gérard, Jean-Claude, Saglam, Adem, Piccioni, Giuseppe, Drossart, Pierre, Montmessin, Frank, Bertaux, Jean-Loup
This VIRTIS instrument on board Venus Express has collected spectrally resolved images of the Venus nightside limb that show the presence of the (0,0) band of the Deltag1-->Sigmag3 infrared...
Gérard, Jean-Claude, Bonfond, Bertrand, Gustin, Jacques, Grodent, Denis, Clarke, J T, Bisikalo, D, ...
Images of Saturn's aurora at the limb have been collected with the Advanced Camera for Surveys on board the Hubble Space Telescope. They show that the peak of Saturn's nightside emission is generally...
Blockx, Caroline, Gérard, Jean-Claude, Coumans, Valérie, Hubert, Benoît, Meurant, M
Substorm energetics has been shown to have two components, the "loading-unloading'' component releasing energy previously stored in the tail and the "directly driven'' component dissipating...
Cox, Cédric, Saglam, Adem, Gérard, Jean-Claude, Bertaux, Jean-Loup, Gonzalez-Galindo, Francesco, Leblanc, François, ...
Limb observations with the SPICAM ultraviolet spectrometer on board the Mars Express orbiter revealed ultraviolet nightglow emission in the delta (190–240 nm) and gamma (225–270 nm) bands of...
Gérard, Jean-Claude, Cox, Cédric, Saglam, Adem, Bertaux, J*-L, Villard, E, Nehmé, C
Limb observations of the spectrum of nightglow emission in the delta (190-240 nm) and gamma (225-270 nm) bands of nitric oxide have been made with the Spectroscopy for Investigation of...
Discontinuity in Jupiter's main auroral oval (2008)
Radioti, Aikaterini, Gérard, Jean-Claude, Grodent, Denis, Bonfond, Bertrand, Krupp, N, Woch, J
On the basis of a series of FUV Hubble Space Telescope images obtained between 1997 and 2007 it is shown that there is a segment of the main auroral oval where the emission drops significantly from a...
Gérard, Jean-Claude, Saglam, Adem, Piccioni, G, Drossart, P, Cox, Cédric, Erard, S, ...
We present characteristics of the statistical horizontal distribution of the O[SUB]2[/SUB] infrared nightglow over most of the southern hemisphere observed with the VIRTIS instrument over a period...
Oscillation of Saturn's southern auroral oval (2008)
Nichols, J D, Clarke, J T, Cowley, S W H, Duval, J, Farmer, A J, Gérard, Jean-Claude, ...
Near-planetary-period oscillations in the Cassini plasma and magnetic field data have been observed throughout Saturn's magnetosphere despite the fact that Saturn's internal magnetic field is...
Cowley, S W H, Arridge, C S, Bunce, E J, Clarke, John T., Coates, A J, Dougherty, Michele K., ...
The first simultaneous observations of fields and plasmas in Saturn's high-latitude magnetosphere and UV images of the conjugate auroral oval were obtained by the Cassini spacecraft and the Hubble...
Bunce, E J, Arridge, C S, Clarke, J T, Coates, A J, Cowley, S W H, Dougherty, Michele K., ...
Outer planet auroras have been imaged for more than a decade, yet understanding their physical origin requires simultaneous remote and in situ observations. The first such measurements at Saturn were...
Jupiter's changing auroral location (2008)
Grodent, Denis, Gérard, Jean-Claude, Radioti, Aikaterini, Bonfond, Bertrand, Saglam, Adem
[1] We examine the case of significant latitudinal shifts of the Jovian northern auroral emissions appearing in a data set spanning nine years of observations with the Hubble Space Telescope in the...
Radioti, Aikaterini, Grodent, Denis, Gérard, Jean-Claude, Bonfond, Bertrand, Clarke, J T
We report the presence of polar spots located in the dawn auroral region, based on the HST ACS 2007 campaign. We study the location of these features in the equatorial plane as well as their time...
Auroral evidence of a localized magnetic anomaly in Jupiter's northern hemisphere (2008)
Grodent, Denis, Bonfond, Bertrand, Gérard, Jean-Claude, Radioti, Aikaterini, Gustin, Jacques, Clarke, John T, ...
We analyze more than 1000 HST/Advanced Camera for Survey images of the ultraviolet auroral emissions appearing in the northern hemisphere of Jupiter. The auroral footprints of Io, Europa, and...
A dynamic upper atmosphere of Venus as revealed by VIRTIS on Venus Express (2007)
Drossart, P, Piccioni, G, Gérard, Jean-Claude, Lopez-Valverde, MA, Sanchez-Lavega, A, Zasova, L, ...
The upper atmosphere of a planet is a transition region in which energy is transferred between the deeper atmosphere and outer space. Molecular emissions from the upper atmosphere (90-120 km...
Bertaux, JL, Nevejans, D, Korablev, O, Villard, E, Quemerais, E, Neefs, E, ...
Spectroscopy for the investigation of the characteristics of the atmosphere of Venus (SPICAV) is a suite of three spectrometers in the UV and IR range with a total mass of 13.9 kg flying on the Venus...
Blockx, Caroline, Gérard, Jean-Claude, Coumans, Valérie, Hubert, Benoît, Meurant, M
In a previous study, Blockx et al. (2005) showed that the SI12 camera on board the IMAGE spacecraft is an excellent tool to remotely determine the position of the isotropy boundary (IB) in the...
Energetic oxygen atoms in the polar geocorona (2006)
Shematovich, VI, Bisikalo, DV, Gérard, Jean-Claude
[ 1] The role of the auroral sources induced by the electron and proton precipitation in the formation of the hot oxygen corona in the polar upper atmosphere is studied. It is found that both...
Hubert, Benoît, Palmroth, Minna, Laitinen, Tiera V., Janhunen, Pekka, Milan, Steve E., Grocott, Adrian, ...
We use a novel method to evaluate the global opening and closure of magnetic flux in the terrestrial system, and to analyse two interplanetary shock passages that occurred during magnetically quiet...
Coumans, Valérie, Gérard, Jean-Claude, Hubert, Benoît, Meurant, M
The brightness of proton aurora observed near solar maximum at summer and winter solstices with the FUV-SI12 global imager on board the IMAGE satellite has been correlated with the solar wind and the...
Morphology of the ultraviolet Io footprint emission and its control by Io's location (2006)
Gérard, Jean-Claude, Saglam, Adem, Grodent, Denis, Clarke, JT
[1] A total of 74 images of the ultraviolet footprint of the Io flux tube (IFT) on Jupiter's upper atmosphere made with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope...
Far ultraviolet remote sensing of the isotropy boundary and magnetotail stretching (2005)
Blockx, Caroline, Gérard, Jean-Claude, Meurant, M, Hubert, Benoît, Coumans, Valérie
Several studies have attempted to identify the isotropy boundary (IB) defining the limit between the adiabatic and nonadiabatic trajectories of the trapped protons along closed magnetic field lines....
Comparison of intense nightside shock-induced precipitation and substorm activity (2005)
Meurant, M, Gérard, Jean-Claude, Blockx, Caroline, Coumans, Valérie, Hubert, Benoît, Connors, M, ...
[1] Sudden variations of the solar wind dynamic pressure frequently induce dayside enhancements of auroral activity with features such as high-latitude arcs, low-latitude proton flashes, and...
An Earth-like correspondence between Saturn's auroral features and radio emission (2005)
Kurth, William S., Gurnett, Donald A., Clarke, John T., Zarka, Philippe, Desch, Michael D., Kaiser, Michael L., ...
Saturn is a source of intense kilometre-wavelength radio emissions that are believed to be associated with its polar aurorae(1,2), and which provide an important remote diagnostic of its...
Morphological differences between Saturn's ultraviolet aurorae and those of Earth and Jupiter (2005)
Clarke, JT, Gérard, Jean-Claude, Grodent, Denis, Wannawichian, S, Gustin, Jacques, Connerney, J, ...
It has often been stated that Saturn's magnetosphere and aurorae are intermediate between those of Earth, where the dominant processes are solar wind driven(1), and those of Jupiter, where processes...
Crary, Frank J., Clarke, John T., Dougherty, Michele K., Hanlon, P. G., Hansen, K. C., Steinberg, John T., ...
The interaction of the solar wind with Earth's magnetosphere gives rise to the bright polar aurorae and to geomagnetic storms(1), but the relation between the solar wind and the dynamics of the outer...
Coumans, Valérie, Gérard, Jean-Claude, Hubert, Benoît, Mende, SB, Cowley, SWH
Observations with the FUV imagers on board the IMAGE satellite have been used to map the auroral electron and proton energy fluxes during the summer and winter solstices of 2000, in order to...
Coumans, Valérie, Gérard, Jean-Claude, Hubert, Benoît, Meurant, M, Mende, SB
The Far Ultraviolet (FUV) imaging system on board the IMAGE satellite provides a global view of the north auroral region in three spectral channels, including the SI 12 camera sensitive to Doppler...
Meurant, M, Gérard, Jean-Claude, Hubert, Benoît, Coumans, Valérie, Blockx, Caroline, Ostgaard, N, ...
[1] On April 28 2001, simultaneous global images of electron and proton aurora were obtained by IMAGE- FUV following a sudden increase of solar wind dynamic pressure. The local time and intensity...
High resolution FUV observations of proton aurora (2003)
Chua, DH, Dymond, KF, Budzien, SA, McCoy, RP, Gérard, Jean-Claude, Coumans, Valérie, ...
We present new FUV observations of Doppler-shifted Lyman-alpha emissions from proton aurora obtained from the High Resolution Ionospheric and Thermospheric Spectrograph ( HITS) aboard the Advanced...
Meurant, M, Gérard, Jean-Claude, Hubert, Benoît, Coumans, Valérie, Shematovich, VI, Bisikalo, DV, ...
[1] The FUV imager on board the IMAGE satellite provides simultaneous images of the north polar aurora every 2 min in three spectral channels. The Wideband Imaging Camera (WIC) responds primarily to...
Excitation of the FUV Io tail on Jupiter: Characterization of the electron precipitation (2002)
Gérard, Jean-Claude, Gustin, Jacques, Grodent, Denis, Delamere, P, Clarke, JT
[1] Spectral observation of both polar regions of Jupiter in the far ultraviolet (FUV) obtained with the Space Telescope Imaging Spectrograph (STIS), on board the Hubble Space Telescope from July...
Ultraviolet emissions from the magnetic footprints of Io, Ganymede and Europa on Jupiter (2002)
Clarke, JT, Ajello, Joseph M., Ballester, G, Ben Jaffel, Lofti, Connerney, J, Gérard, Jean-Claude, ...
Io leaves a magnetic footprint on Jupiter's upper atmosphere that appears as a spot of ultraviolet emission that remains fixed underneath Io as Jupiter rotates(1-3). The specific physical mechanisms...
The role of proton precipitation in the excitation of auroral FUV emissions (2001)
Hubert, Benoît, Gérard, Jean-Claude, Bisikalo, D V, Shematovich, V I, Solomon, S C
Far ultraviolet remote sensing from a high-altitude satellite is extensively used to image the global aurora, derive its energetics, and follow its dynamical morphology. It is generally assumed that...
The electron and proton aurora as seen by IMAGE-FUV and FAST (2001)
Frey, H U, Mende, S B, Carlson, C W, Gérard, Jean-Claude, Hubert, Benoît, Spann, J, ...
The Far Ultraviolet Instrument (FUV) on the IMAGE spacecraft observes the aurora in three different channels. One of them (SI12) is sensitive to the signal from precipitating protons, while the other...
Ion outflow observed by IMAGE: Implications for source regions and heating mechanisms (2001)
Fuselier, S A, Ghielmetti, A G, Moore, T E, Collier, M R, Quinn, J M, Wilson, G R, ...
Images of the Earth's proton aurora from the IMAGE spacecraft on 8 June 2000 indicate a temporally and spatially isolated ionospheric response to a shock that impinged on the Earth's magnetopause....
Global observations of proton and electron auroras in a substorm (2001)
Mende, S B, Frey, H U, Lampton, M, Gérard, Jean-Claude, Hubert, Benoît, Fuselier, S, ...
This is the first report of a substorm observed by the IMAGE FUV instruments permitting global observations of electron and proton produced auroras. On the 28th of June 2000 at 1956 UT in the...
Modelling short-term CO2 fluxes and long-term tree growth in temperate forests with ASPECTS (2001)
François, Louis, Aubinet, M, Kowalski, AS, Vande Walle, I, Laitat, E, Gérard, Jean-Claude
The net ecosystem exchange (NEE) Of CO2 between temperate forests and the atmosphere governs both carbon removal from the atmosphere and forest growth. In recent years, many experiments have been...
A model of the Lyman-alpha line profile in the proton aurora (2000)
Gérard, Jean-Claude, Hubert, Benoît, Bisikalo, Dimitry V, Shematovich, Valery I
The Lyman-alpha auroral emission is characterized by a broad line profile whose shape depends on the energy and pitch angle distributions of the initial proton beam, whereas its total brightness...
A model of the Lyman-alpha line profile in the proton aurora (2000)
Gérard, Jean-Claude, Hubert, Benoît, Bisikalo, Dimitry V, Shematovich, Valery I
The Lyman-alpha auroral emission is characterized by a broad line profile whose shape depends on the energy and pitch angle distributions of the initial proton beam, whereas its total brightness...
Mende, S B, Heetderks, H, Frey, H U, Stock, J M, Lampton, M, Geller, S P, ...
Two FUV Spectral imaging instruments, the Spectrographic Imager (SI) and the Geocorona Photometer (GEO) provide IMAGE with simultaneous global maps of the hydrogen (121.8 nm) and oxygen 135.6 nm...
Far ultraviolet imaging from the IMAGE spacecraft. 1. System design (2000)
Mende, S B, Heetderks, H, Frey, H U, Lampton, M, Geller, S P, Habraken, Serge, ...
Direct imaging of the magnetosphere by the IMAGE spacecraft will be supplemented by observation of the global aurora, the footprint of magnetospheric regions. To assure the simultaneity of these...
Effect of hot oxygen on thermospheric O I UV airglow (1999)
Hubert, Benoît, Gérard, Jean-Claude, Cotton, D M, Bisikalo, D V, Shematovich, V I
The role of nonthermal oxygen atoms in the vertical distribution of the O I 989 Å EUV multiplet intensity is investigated using a thermospheric radiative transfer code. The superthermal oxygen...
Thermalization of O([SUP]1[/SUP]D) atoms in the thermosphere (1999)
Shematovich, Valery, Gérard, Jean-Claude, Bisikalo, Dimitry V, Hubert, Benoît
Measurements of the Doppler width of the 6300 Å airglow emission line have been extensively used to determine the thermospheric temperature. This technique is based on the assumption that the bulk...
Nemry, B, François, Louis, Gérard, Jean-Claude, Bondeau, A, Heimann, M
Eight terrestrial biospheric models (TBMs) calculating the monthly distributions of both net primary productivity (NPP) and soil heterotrophic respiration (R-H) in the Potsdam NPP Model...
The interannual change of atmospheric CO2: contribution of subtropical ecosystems? (1999)
Gérard, Jean-Claude, Nemry, B, François, Louis, Warnant, Pierre
The global terrestrial carbon cycle model CARAIB (CARbon Assimilation In the Biosphere) is used to study the response of the terrestrial ecosystems to the large scale climate variations over the...
Hubble Space Telescope imaging of Jupiter's UV aurora during the Galileo orbiter mission (1998)
Clarke, John T, Ben Jaffel, Lotfi, Gérard, Jean-Claude
Hubble Space Telescope (HST) Wide-Field Planetary Camera 2 (WFPC 2) images of Jupiter's aurora have been obtained close in time with Galileo ultraviolet spectrometer (UVS) spectra and in situ...
Gérard, Jean-Claude, Grodent, Denis, Dols, V, Waite, JH
A three-dimensional model is used to assess the role of the viewing geometry on the auroral color ratio. The simulations show that both an auroral are with a geometry deduced from images obtained...
HST spectra of the Jovian ultraviolet aurora: Search for heavy ion precipitation (1998)
Trafton, LM, Dols, V, Gérard, Jean-Claude, Waite, JH, Gladstone, GR, Munhoven, Guy
Ultraviolet spectra using Hubble Space Telescope sampled between 1250 and 1680 Angstrom, at spectral resolution less than or equal to 0.57 Angstrom are reported for characteristically bright regions...
Fesen, C G, Gérard, Jean-Claude, Hays, P B, Anderson, D N
Not Available
An updated model of the hot nitrogen atom kinetics and thermospheric nitric oxide (1997)
Gérard, Jean-Claude, Bisikalo, D V, Shematovich, V I, Duff, J W
New observations and reanalysis of previous measurements suggest an upward revision of the measured thermospheric nitric oxide density. Our previous model of NO production by fast N([SUP]4[/SUP]S)...
Bisikalo, D V, Shematovich, V I, Gérard, Jean-Claude, Gladstone, G R, Waite, J H
The energy distribution functions of nonthermal thermospheric hydrogen atoms are calculated for electron and proton precipitation in the Jovian aurora. A numerical model taking into account the...
Nemry, B, François, Louis, Warnant, Pierre, Robinet, F, Gérard, Jean-Claude
Two simulations of the seasonal variation of the global atmospheric CO2 distribution are obtained by combining an atmospheric transport model, two parameterizations of soil heterotrophic respiration...
Hubert, Benoît, Gérard, Jean-Claude, Shematovich, Valeri I, Bisikalo, Dimitri V
The reaction between superthermal N([SUP]4[/SUP]S) atoms produced by exothermic processes and O[SUB]2[/SUB] has been proposed to explain observations of highly rotationally excited nitric oxide in...
Prange, Renee, Rego, Daniel, Gérard, Jean-Claude
Previous spectral analyses have given evidence of collisionally excited Jovian and (at times) Saturnian H2 Werner bands being absorbed by hydrocarbons at the shortest wavelengths along the auroral...
HST Far-Ultraviolet Imaging of Jupiter During the Impacts of Comet Shoemaker-Levy 9 (1995)
Clarke, John T, Prange, Renee, Ballester, Gilda E, Trauger, John, Evans, Robin, Rego, Daniel, ...
Hubble Space Telescope far-ultraviolet images of Jupiter during the Shoemaker-Levy 9 impacts show the impact regions darkening over the 2 to 3 hours after the impact, becoming darker and more...
Delire, Christine, Gérard, Jean-Claude
Global models including atmospheric, oceanic, and biogeochemical processes are needed for the study of possible environmental changes, but they require efficient approximations of physical processes...
Bisikalo, D V, Shematovich, V I, Gérard, Jean-Claude
A model for the oxygen geocorona near the exobase solving the nonlinear Boltzmann equation with a Monte Carlo method is used to calculate the distribution of the hot oxygen atoms during...
The importance of new chemical sources for the hot oxygen geocorona (1995)
Gérard, Jean-Claude, Richards, P G, Shematovich, V I, Bisikalo, D V
Exothermic reactions involving metastable neutrals and ions were recently proposed as sources of hot oxygen atoms in addition to the classical O2(+) and NO(+) dissociative recombination. The...
SIMULTANEOUS OBSERVATIONS OF THE SATURNIAN AURORA AND POLAR HAZE WITH THE HST/FOC (1995)
Gérard, Jean-Claude, DOLS, V, Grodent, Denis, WAITE, JH, GLADSTONE, GR, PRANGE, R
Near simultaneous observations of the Saturnian H-2 north ultraviolet aurora and the polar haze were made at 153 nm and 210 nm respectively with the Faint Object Camera on board the post-COSTAR...
A kinetic model of the formation of the hot oxygen geocorona. 1: Quiet geomagnetic conditions (1994)
Shematovich, V I, Bisikalo, D V, Gérard, Jean-Claude
A model of the hot oxygen geocorona in the transition region near the exobase is described. It is based on a Monte Carlo solution of the nonlinear Boltzmann equation for hot oxygen atoms produced by...
Gérard, Jean-Claude, Dols, Vincent, Prange, Renee, Paresce, Francesco
A series of six images covering a complete rotation of the north polar region of Jupiter were obtained in February 1993 with the Faint Object Camera on board the Hubble Space Telescope (HST). These...
Rego, Daniel, Prange, Renee, Gérard, Jean-Claude
This paper is part of a work aimed at modeling the ratio of the observed Jovian auroral intensity at H Lyman-alpha and in the H2 Lyman and Werner bands and interpreting them as diagnostic of the...
Clarke, John T, Ben Jaffel, Lotfi, Vidal-Madjar, Alfred, Gladstone, G Randall, Prange, Renee, ...
We have observed the emission spectrum from Jupiter's north auroral atmosphere with 0.57 A spectral resolution over 1204-1241 A. Bright emissions have been detected from 50 deg to 60 deg latitude at...
Gérard, Jean-Claude, Grodent, Denis, Prangé, R., Waite, J. H., Gladstone, G. R., Dols, V., ...
Two sets of ultraviolet images of the Jovian north aurora were obtained with the Faint Object Camera on board the Hubble Space Telescope. The first series shows an intense discrete are in near...
TRAFTON, LM, Gérard, Jean-Claude, Munhoven, Guy, WAITE, JH
The first spectroscopic observations of planetary aurora with the HST are reported. These include spectral regions centered on the H-2 Lyman and Werner bands of a region of Jupiter's northern aurora....
CARAIB - A GLOBAL-MODEL OF TERRESTRIAL BIOLOGICAL PRODUCTIVITY (1994)
Warnant, Pierre, François, Louis, Strivay, David, Gérard, Jean-Claude
CARAIB, a mechanistic model of carbon assimilation in the biosphere estimates the net primary productivity (NPP) of the continental vegetation on a grid of 1 degrees x 1 degrees in latitude and...
Gérard, Jean-Claude, Dols, Vincent, Paresce, Francesco, Prange, Renee
High spatial resolution images of the north polar region of Jupiter have been obtained with the Faint Object Camera (FOC) on board the Hubble Space Telescope (HST). The first set of two images...
Gérard, Jean-Claude, Shematovich, V I, Bisikalo, D V
The variation of the nitric oxide peak density near 110 km with solar activity is calculated using a photochemical diffusive model of thermospheric odd nitrogen. This model includes the reaction of...
Effect of hot N(4S) atoms on the NO solar cycle variation in the lower thermosphere (1993)
Gérard, Jean-Claude, Shematovich, V I, Bisikalo, D V
The variation of the nitric oxide peak density near 110 km with solar activity is calculated using a photochemical diffusive model of thermospheric odd nitrogen. This model includes the reaction of...
A first look at the ASSI ultraviolet results (1993)
Chakrabarti, S, Gladstone, G R, Tobiska, W K, Schmidtke, G, Doll, H, Gérard, Jean-Claude
The Airglow and Solar Spectrometer Instrument (ASSI) on the San Marco D satellite has obtained near-simultaneous measurements of solar irradiances and airglow emissions in the 200-7000 A spectral...
The thermospheric odd nitrogen photochemistry - Role of non thermal N(4S) atoms (1992)
Shematovich, V I, Bisikalo, D V, Gérard, Jean-Claude
A nonequilibrium model to calculate the Maxwellian 'hot' N(4S) atom population using a Monte Carlo method is developed, and the NO vertical distribution for minimum solar cycle conditions is...
Ultraviolet imaging of the Jovian aurora with the Hubble Space Telescope (1992)
Dols, V, Gérard, Jean-Claude, Paresce, F, Prange, R, Vidal-Madjar, A
We present here for the first time a Lyman-alpha image of the north polar region of Jupiter obtained with the Faint Object Camera on board the Hubble Space Telescope a few hours after the encounter...
Friedlingstein, P, Delire, C, Müler, J F, Gérard, Jean-Claude
A simplified three-dimensional global climate model was used to simulate the surface temperature and precipitation distributions for the Last Glacial Maximum (LGM), 18000 years ago. These fields were...
Thermospheric odd nitrogen (1992)
The photochemistry of NO, N(2D) and N(4S) and results of recent space measurements of their density distribution are discussed. In particular, the role of the reaction between metastable N(2D) atoms...
Gérard, Jean-Claude, HAUGLUSTAINE, DA, François, Louis
A seasonal one-and-a-half-dimensional (1 1/2-D) energy-balance climate model including a detailed sea ice calculation and an interactive albedo formulation has been developed and is used to...
Gérard, Jean-Claude, Hauglustaine, D A, François, Louis
A seasonal one-and-a-half-dimensional (1 1/2-D) energy-balance climate model including a detailed sea ice calculation and an interactive albedo formulation has been developed and is used to...
Non thermal nitrogen atoms in the Earth's thermosphere. 2. A source of nitric oxide (1991)
Gérard, Jean-Claude, Shematovich, V I, Bisikalo, D V
The role of the non maxwellian nitrogen atoms in the odd nitrogen thermospheric chemistry is investigated with a numerical model. This one-dimensional model solves the continuity equation, including...
Shematovich, V I, Bisikalo, D V, Gérard, Jean-Claude
The energy distribution of translationally hot nitrogen atoms in the thermosphere has been calculated using a nonequilibrium kinetic model. Dissociation by solar EUV photons and photoelectrons is...
Rusch, D W, Gérard, Jean-Claude, Fesen, C G
A data base of parameters important to understanding the diurnal variation of odd-nitrogen and ions in the thermosphere near equinox, at low latitudes, and for quiet geomagnetic conditions is...
The latitudinal gradient of the NO peak density (1990)
Fesen, C G, Rusch, D W, Gérard, Jean-Claude
Results are presented from SME observations of the latitudinal gradients of peak NO densities at about 110-km altitude during the solstice and equinox periods from 1982 through 1985. It is shown that...
The warm Cretaceous climate - Role of the long-term carbon cycle (1990)
Gérard, Jean-Claude, Dols, Vincent
An annual energy-balance model is coupled to a steady state formulation of the long-term CO2 cycle to investigate the possible sources of global warming of the Cretaceous period. It is found that...
Solar cycle variation of thermospheric nitric oxide at solstice (1990)
Gérard, Jean-Claude, Fesen, C G, Rusch, D W
A coupled, two-dimensional, chemical-diffusive model of the thermosphere is used to study the role of solar activity in the global distribution of nitric oxide. The model calculates self-consistently...
Bougher, S W, Gérard, Jean-Claude, Stewart, A I F, Fessen, C G
The mechanism responsible for the Venus nitric oxide (0,1) delta band nightglow observed in the Pioneer Venus Orbiter UV spectrometer (OUVS) images was investigated using the Venus Thermospheric...
Modelling the Climatic Response to Solar Variability: Discussion (1990)
Pecker, J*-C, Gérard, Jean-Claude
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Modelling the Climatic Response to Solar Variability (1990)
The Sun, the primary energy source driving the climate system, is known to vary in time both in total irradiance and in spectral composition in the ultraviolet. According to solar interior evolution...
Gérard, Jean-Claude, DELCOURT, D, François, Louis
Current theories of stellar evolution imply that the solar luminosity was 25-30% less than at present during early phases of the Earth's history. The response of the global annual climate to changes...
A MODEL OF SOLAR-CYCLE EFFECTS ON PALEOCLIMATE AND ITS IMPLICATIONS FOR THE ELATINA FORMATION (1987)
François, Louis, Gérard, Jean-Claude
A reservoir model describing the time evolution of the sedimentary cycle of sulfur over the past 800 my has been developed. As a first approximation, the ocean sulfate concentration is assumed to be...
Gérard, Jean-Claude, Noel, Caroline
Measurements of the NO gamma(1,0) band resonance scattering distribution obtained with the Atmosphere Explorer D satellite have been inverted to generate maps of the meridional distribution of nitric...
Measurements of the E-region electron density were made with the Saint-Santin incoherent scatter radar during consecutive days in June 1978, March 1979 and December 1980. On the basis of a...
Reducing Power of Ferrous Iron in the Archean Ocean, 1. Contribution of Photosynthetic Oxygen (1986)
François, Louis, Gérard, Jean-Claude
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Cravens, T E, Gérard, Jean-Claude, Lecompte, M, Stewart, A I, Rusch, D W
The ultraviolet nitric oxide spectrometer (UVNO) experiment on the Atmosphere Explorer D (AE-D) satellite measured thermospheric nitric oxide during the winter of 1974-1975 using resonant...
The transport of thermospheric nitric oxide into the mesosphere (1984)
Gérard, Jean-Claude, Deneye, E J F
A ratio phi/K of vertical nitric oxide flux to the eddy diffusion coefficient is derived to estimate the magnitude of nitric oxide transport from the thermosphere into the mesosphere. Rocket...
Gérard, Jean-Claude, Roble, R G, Rusch, D W, Stewart, A I
A two-dimensional model of odd nitrogen in the thermosphere and upper mesosphere is described. The global distributions of nitric oxide and atomic nitrogen are calculated for the solstice period for...
The thermospheric heating efficiency under electron precipitation conditions (1982)
The results of a study of the altitude distribution of particle heating due to magnetospheric electron penetration into the atmosphere are presented. Updated chemical species data were used in the...
Transport of aurorally produced N/2D/ by winds in the high latitude thermosphere (1982)
Gérard, Jean-Claude, Roble, R G
A time-dependent, two-dimensional model is developed for describing the meridional circulation of thermospheric odd nitrogen species produced in the auroral zone. The model is based on a previous...
A model of the interaction between incident electron precipitation and H2 atmospheres is described. The local degraded primary and secondary electron energy distributions are calculated by using the...
Solomon, S, Rusch, D W, Gérard, Jean-Claude, Reid, G C, Crutzen, P J
A one dimensional time-dependent model of the neutral and ion chemistry of the middle atmosphere has been used to examine the production of odd hydrogen (H, OH, and HO2) during charged particle...
Rusch, D W, Gérard, Jean-Claude, Solomon, S, Crutzen, P J, Reid, G C
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Gérard, Jean-Claude, Stewart, A I F, Bougher, S W
The altitude distribution of the nitric oxide nightglow was measured with an ultraviolet spectrometer on board Pioneer Venus, in order to study the effects of the distribution on the Venus nightside...
Morphology of the Venus ultraviolet night airglow (1980)
Stewart, A I F, Gérard, Jean-Claude, Rusch, D W, Bougher, S W
Images of the nightside of Venus in the (0,1)delta band of nitric oxide have been obtained by the Pioneer Venus orbiter ultraviolet spectrometer (OUVS). The emission, which is produced by radiative...
Metastable N/2P/ atoms in the aurora (1980)
Gérard, Jean-Claude, Harang, O E
Auroral spectra have been obtained in the 3380- to 3560-A region to study the forbidden N I 4S-2P doublet at 3466 A. The forbidden N I 3466 A/N2 Vegard-Kaplan ratio is found to remain constant. This...
Satellite studies of N/D-2/ emission and ion chemistry in aurorae (1980)
Rusch, D W, Gérard, Jean-Claude
The incident particle flux ion and neutral composition data taken on the AE-D satellite have been used to investigate the quantal emission of N2(plus) at 4278 A, N(D-2) at 5200 A, and the ion...
Gérard, Jean-Claude, Rusch, D W, Hays, P B, Fesen, C L
The Visible Airglow Experiment on the Atmosphere Explorer E satellite has observed the resonantly scattered emission from Mg II at 2800 A in the equatorial ionosphere. Altitude profiles of the...
The auroral ionosphere - Comparison of a time-dependent model with composition measurements (1979)
Gérard, Jean-Claude, Rusch, D W
A time-dependent model of the auroral ionosphere including the odd nitrogen species, NO, N(D-2), and N(S-4), is used for comparison with data from a coordinated rocket-satellite measurement of an...
The latitudinal gradient of nitric oxide in the thermosphere (1979)
Cravens, T E, Gérard, Jean-Claude, Stewart, A I, Rusch, D W
Theoretical calculations of nitric oxide altitude profiles are made at five different latitudes by using neutral temperatures and composition primarily from the MSIS (mass spectrometer and incoherent...
The reaction of N/2D/ with O2 as a source of O/1D/ atoms in aurorae (1978)
Rusch, D W, Sharp, W E, Gérard, Jean-Claude
The source of O(1D) atoms in the auroral ionosphere is investigated using sounding rocket data. Previously, it has been shown that the conventional sources of O(1D) atoms in the aurora, dissociative...
The Mg II equatorial airglow altitude distribution (1978)
Gérard, Jean-Claude, Monfils, A
Four occasional measurements of the altitude distribution of the 2796-2803-Å doublet equatorial airglow have been made with the astronomical TD-1A satellite during winter 1973-1974. The observations...
Magnetic storm effects on the tropical ultraviolet airglow (1977)
Gérard, Jean-Claude, Anderson, D N, Matsushita, S
Ogo 4 measurements of the UV equatorial airglow made during a period which included a major magnetic storm are analyzed and used as an indicator of wind direction and velocity as well as ExB drift...
High-latitude nitric oxide in the lower thermosphere (1977)
Gérard, Jean-Claude, Barth, C A
High-latitude observations of fluorescent nitric oxide gamma bands were made before and during a strong magnetic storm with the Ogo 4 ultraviolet spectrometer. Brightness measurements of the (1-0)...
OGO-4 observations of the ultraviolet auroral spectrum (1976)
Gérard, Jean-Claude, Barth, C A
Auroral ultraviolet spectra in the range from 1200 to 3200 A have been obtained by the spectrometer on board the OGO-4 satellite. Emissions of N2, H, O, and N are readily identified. Atomic and...
Shepherd, G G, Pieau, J F, Creutzberg, F, McNamara, A G, Gérard, Jean-Claude, McEwen, D J, ...
On Dec. 6, 1974, a Black Brant VD rocket was launched from Cape Parry, N.W.T., into the dayside magnetospheric cleft. The prime launch criterion was the detection of 6300-A emission by two...
Rocket-borne baffled photometer - Design and calibration (1976)
Marette, G, Gérard, Jean-Claude
The design of an interference filter twin photometer suitable for the observation by rocket of the daytime magnetospheric cleft aurora at 2761 A and 5200 A is presented. The two-stage baffling system...
Satellite measurements of high-altitude twilight Mg/plus/ emission (1976)
Observations made by the ultraviolet spectrometer on board the orbiting geophysical observatory OGO 4 confirmed the presence of resonance scattering at 2800 A of Mg(plus) ions in the twilight...
Photometric measurements of the O2 U.V. nightglow (1975)
The O2 Herzberg system in the night airglow was measured in the wavelength range 2400 to 3100 A by the S2/68 UV telescope aboard the ESRO TD-1 satellite. The statistical latitudinal variations of the...
Ground-based photometric observations of the type A aurora of 17-18 December 1971 (1974)
Ground-based observations have been made during the event of 17-18 Dec. 1971 from northern Norway, using a tilting-filter photometer monitoring the intensities of N2(plus) 1.Neg., H-beta, 6300-A O-I,...
Satellite observations of the equatorial Mg II dayglow intensity distribution. (1974)
Gérard, Jean-Claude, Monfils, A
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Ultraviolet observations of equatorial dayglow above the F[SUB]2[/SUB] peak. (1973)
Boksenberg, A, Gérard, Jean-Claude
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