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1. Auroral 3D structure retrieval from the Juno/UVS data.

Author

Benmahi, B., Bonfond, B., Benne, B., Hue, V., Grodent, D., Barthélemy, M., Sinclair, J. A., Moirano, A., Head, L. A., Gladstone, R., Gronoff, G., Sicorello, G., Simon Wedlund, C., Giles, R., and Greathouse, T. K.

Subjects
NATURAL satellite atmospheres, NATURAL satellites, ATMOSPHERE of Jupiter, AURORAS, PLASMA gases
Abstract

Context. Jovian auroras, the most powerful in the Solar System, result from the interaction between the magnetosphere and atmosphere of Jupiter. While the horizontal morphology of these phenomena has been widely studied, their vertical structure, determined by the penetration depth of the magnetospheric electron into the auroral regions, remains relatively unexplored. Previous observations, including those from the Hubble Space Telescope (HST), have addressed this question to a limited extent. Aims. In this study we aim to map the vertical structure of Jovian auroral emissions. Methods. Using observations from Juno's UltraViolet Spectrograph (UVS), we examined the vertical structure of the auroral emissions. Building on a recent study of auroral energy mapping based on UVS observations that mapped the average energy of precipitating electrons in the Jovian auroral regions, we find a relationship between this average energy and the volume emission rate (VER) of H2 for two types of electron energy distributions: monoenergetic and a kappa distribution with κ = 2.5. Results. Using brightness maps, we derived the 3D VER structure of Jovian auroras in both northern and southern regions, across multiple spacecraft perijoves (PJs). By considering the example of PJ11, we find that the average altitude of the VER peak in the polar emission region is approximately ~250 km for the monoenergetic distribution case and ~190 km for kappa distribution case. In the main emission region, we find that the average altitude of the VER peak is approximately ~260 km for the case of monoenergetic distribution and ~197 km for kappa distribution case. For the other PJs, we obtained results that are very similar to those of PJ11. Conclusions. Our findings are, on average, consistent with measurements from the Galileo probe and the HST observations. This study contributes to a better understanding of the complexity of Jovian auroras and highlights the importance of using Juno observations when probing their vertical structure. Considering the variability in the κ parameter in the auroral region, we also studied the impact of this variability on the vertical structure of the auroral emission. This sensitivity study reveals that the influence of the κ parameter on our results was very weak. However, the impact of the κ variability on the VER amplitude shows that there is an influence on the thermal structure and chemical composition of the atmosphere in the auroral regions. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Regions of interest on Ganymede's and Callisto's surfaces as potential targets for ESA's JUICE mission

Author

Stephan, K., Roatsch, T., Tosi, F., Matz, K.-D., Kersten, E., Wagner, R., Molyneux, P., Palumbo, P., Poulet, F., Hussmann, H., Barabash, S., Bruzzone, L., Dougherty, M., Gladstone, R., Gurvits, L.I., Hartogh, P., Iess, L., Wahlund, J.-E., Wurz, P., Witasse, O., Grasset, O., Altobelli, N., Carter, J., Cavalié, T., d'Aversa, E., Della Corte, V., Filacchione, G., Galli, A., Galluzzi, V., Gwinner, K., Hauber, E., Jaumann, R., Krohn, K., Langevin, Y., Lucchetti, A., Migliorini, A., Piccioni, G., Solomonidou, A., Stark, A., Tobie, G., Tubiana, C., Vallat, C., and Van Hoolst, T.

Published
2021
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3. Precipitating Electron Energy Flux and Characteristic Energies in Jupiter's Main Auroral Region as Measured by Juno/JEDI

Author

Clark, G, Tao, C, Mauk, B. H, Nichols, J, Saur, J, Bunce, E. J, Allegrini, F, Gladstone, R, Bagenal, F, Bolton, S, Bonfond, B, Connerney, J, Ebert, R. W, Gershman, D. J, Haggerty, D, Kimura, T, Kollmann, P, Kotsiaros, S, Kurth, W. S, Levin, S, McComas, D. J, Murakami, G, Paranicas, C, Rymer, A, and Valek, P

Subjects
Lunar And Planetary Science And Exploration
Abstract

The relationship between electron energy flux and the characteristic energy of electron distributions in the main auroral loss cone bridges the gap between predictions made by theory and measurements just recently available from Juno. For decades such relationships have been inferred from remote sensing observations of the Jovian aurora, primarily from the Hubble Space Telescope, and also more recently from Hisaki. However, to infer these quantities, remote sensing techniques had to assume properties of the Jovian atmospheric structure - leading to uncertainties in their profile. Juno's arrival and subsequent auroral passes have allowed us to obtain these relationships unambiguously for the first time, when the spacecraft passes through the auroral acceleration region. Using Juno /Jupiter Energetic particle Detector Instrument (JEDI), an energetic particle instrument, we present these relationships for the 30-kiloelectronvolts to 1-megaelectronvolts electron population. Observations presented here show that the electron energy flux in the loss cone is a nonlinear function of the characteristic or mean electron energy and supports both the predictions from Knight (1973, https://doi.org/10.1016/0032-0633(73)90093-7) and magnetohydrodynamic turbulence acceleration theories (e.g., Saur et al., 2003, https://doi.org/10.1029/2002GL015761). Finally, we compare the in situ analyses of Juno with remote Hisaki observations and use them to help constrain Jupiter's atmospheric profile. We find a possible solution that provides the best agreement between these data sets is an atmospheric profile that more efficiently transports the hydrocarbons to higher altitudes. If this is correct, it supports the previously published idea (e.g., Parkinson et al., 2006, https://doi.org/10.1029/2005JE002539) that precipitating electrons increase the hydrocarbon eddy diffusion coefficients in the auroral regions.

Published
2018
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4. Convection in a volatile nitrogen-ice-rich layer drives Plutos geological vigour

Author

McKinnon, William B., Nimmo, Francis, Wong, Teresa, Schenk, Paul M., White, Oliver L., Roberts, J. H., Moore, J. M., Spencer, J. R., Howard, A. D., Umurhan, O. M., Stern, S. A., Weaver, H. A., Olkin, C. B., Young, L. A., Smith, K. E., McKinnon, W. B., Beyer, R., Buie, M., Buratti, B., Cheng, A., Cruikshank, D., Dalle Ore, C., Gladstone, R., Grundy, W., Lauer, T., Linscott, I., Olkin, C., Parker, J., Porter, S., Reitsema, H., Reuter, D., Robbins, S., Schenk, P. M., Showalter, M., Singer, K., Strobel, D., Summers, M., Tyler, L., Weaver, H., White, O. L., Banks, M., Barnouin, O., Bray, V., Carcich, B., Chaikin, A., Chavez, C., Conrad, C., Hamilton, D., Howett, C., Hofgartner, J., Kammer, J., Lisse, C., Marcotte, A., Parker, A., Retherford, K., Saina, M., Runyon, K., Schindhelm, E., Stansberry, J., Steffl, A., Stryk, T., Throop, H., Tsang, C., Verbiscer, A., Winters, H., and Zangari, A.

Subjects
Pluto (Dwarf planet) -- Observations, Astrogeology -- Methods, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): William B. McKinnon (corresponding author) [1]; Francis Nimmo [2]; Teresa Wong [1]; Paul M. Schenk [3]; Oliver L. White [4]; J. H. Roberts [5]; J. M. Moore [4]; J. [...]

Published
2016
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5. Chandra's Observations of Jupiter's X-Ray Aurora During Juno Upstream and Apojove Intervals

Author

Jackman, C.M, Dunn, W, Kraft, R, Gladstone, R, Branduardi-Raymont, G, Knigge, C, Altamirano, D, and Elsner, R

Subjects
Lunar And Planetary Science And Exploration, Astrophysics
Abstract

The Chandra space telescope has recently conducted a number of campaigns to observe Jupiter's X-ray aurora. The first set of campaigns took place in summer 2016 while the Juno spacecraft was upstream of the planet sampling the solar wind. The second set of campaigns took place in February, June and August 2017 at times when the Juno spacecraft was at apojove (expected close to the magnetopause). We report on these upstream and apojove campaigns including intensities and periodicities of auroral X-ray emissions. This new era of jovian X-ray astronomy means we have more data than ever before, long observing windows (up to 72 kiloseconds for this Chandra set), and successive observations relatively closely spaced in time. These features combine to allow us to pursue novel methods for examining periodicities in the X-ray emission. Our work will explore significance testing of emerging periodicities, and the search for coherence in X-ray pulsing over weeks and months, seeking to understand the robustness and regularity of previously reported hot spot X-ray emissions. The periods that emerge from our analysis will be compared against those which emerge from radio and UV wavelengths.

Published
2017

6. Millennial-scale variability in Antarctic ice-sheet discharge during the last deglaciation

Author

Weber, M.E., Clark, P.U., Kuhn, G., Timmermann, A., Sprenk, D., Gladstone, R., Zhang, X., Lohmann, G., Menviel, L., Chikamoto, M.O., Friedrich, T., and Ohlwein, C.

Subjects
Antarctica -- Natural history, Ice sheets -- Natural history, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Our understanding of the deglacial evolution of the Antarctic Ice Sheet (AIS) following the Last Glacial Maximum (26,000-19,000 years ago) (1) is based largely on a few well-dated but temporally and geographically restricted terrestrial and shallow-marine sequences (2-4). This sparseness limits our understanding of the dominant feedbacks between the AIS, Southern Hemisphere climate and global sea level. Marine records of iceberg-rafted debris (IBRD) provide a nearly continuous signal of ice-sheet dynamics and variability. IBRD records from the North Atlantic Ocean have been widely used to reconstruct variability in Northern Hemisphere ice sheets (5), but comparable records from the Southern Ocean of the AIS are lacking because of the low resolution and large dating uncertainties in existing sediment cores. Here we present two well-dated, high-resolution IBRD records that capture a spatially integrated signal of AIS variability during the last deglaciation. We document eight events of increased iceberg flux from various parts of the AIS between 20,000 and 9,000 years ago, in marked contrast to previous scenarios which identified the main AIS retreat as occurring after meltwater pulse 1A (3,6-8) and continuing into the late Holocene epoch. The highest IBRD flux occurred 14,600 years ago, providing the first direct evidence for an Antarctic contribution to meltwater pulse 1A. Climate model simulations with AIS freshwater forcing identify a positive feedback between poleward transport of Circumpolar Deep Water, subsurface warming and AIS melt, suggesting that small perturbations to the ice sheet can be substantially enhanced, providing a possible mechanism for rapid sea-level rise., Today, the estimated total iceberg calving flux from Antarctica is about 1,300-2,000 gigatons per year (Gt [yr.sup.-1]) (9), with giant (longer than 18 km) icebergs representing at least half of [...]

Published
2014
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7. Energetic Charged Particle Observations During Juno's Close Flyby of Ganymede.

Author

Clark, G., Kollmann, P., Mauk, B. H., Paranicas, C., Haggerty, D., Rymer, A., Smith, H. T., Saur, J., Allegrini, F., Duling, S., Ebert, R. W., Kurth, W. S., Gladstone, R., Greathouse, T. K., Li, W., Bagenal, F., Connerney, J. E. P., Bolton, S., Szalay, J. R., and Sulaiman, A. H.

Subjects
PARTICLE detectors, SOLAR system, MAGNETOSPHERE, MAGNETIC fields, ELECTRONS
Abstract

On 7 June 2021, NASA's Juno mission obtained unique measurements of Ganymede's magnetosphere during a close flyby that brought the spacecraft within ∼1,000 km of its surface. Here Jupiter Energetic particle Detector Instrument observations are presented and analyzed. The electron pitch angle distributions reveal distinct regions of Ganymede's magnetosphere that can be characterized as inbound and outbound magnetospheric boundaries, a magnetotail/wake region, and Ganymede's open field line region. Evidence for energy dependent electron pitch angle structuring is also documented both outside and within Ganymede's magnetosphere. Electron precipitation is observed and mapped to Ganymede's surface along Juno's magnetic footpoint. Plain Language Summary: Not only is Ganymede the largest moon in our solar system, it is also the only moon known to generate its own internal magnetic field and mini‐magnetosphere. This makes Ganymede extremely fascinating to study. On 7 June 2021, NASA's Juno mission performed a historic flyby with a closest approach altitude of ∼1,000 km above its surface. The data collected by Juno is providing us with new insights into this unique mini‐magnetosphere. This letter focuses on the energetic ion and electron environment that surrounds Ganymede and the features revealed by Juno's Jupiter Energetic particle Detector Instrument. Key Points: Energetic particle measurements reveal new insights into Ganymede's magnetosphere for the only close Juno flybyElectron pitch angle distributions reveal distinct regions of Ganymede's magnetosphereEvidence for energetic electron precipitation onto Ganymede's surface within the open field line region [ABSTRACT FROM AUTHOR]

Published
2022
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8. PHEBUS: A double ultraviolet spectrometer to observe Mercury's exosphere

Author

Chassefière, E., Maria, J.-L., Goutail, J.-P., Quémerais, E., Leblanc, F., Okano, S., Yoshikawa, I., Korablev, O., Gnedykh, V., Naletto, G., Nicolosi, P., Pelizzo, M.-G., Correia, J.-J., Gallet, S., Hourtoule, C., Mine, P.-O., Montaron, C., Rouanet, N., Rigal, J.-B., Muramaki, G., Yoshioka, K., Kozlov, O., Kottsov, V., Moisseev, P., Semena, N., Bertaux, J.-L., Capria, M.-Th., Clarke, J., Cremonese, G., Delcourt, D., Doressoundiram, A., Erard, S., Gladstone, R., Grande, M., Hunten, D., Ip, W., Izmodenov, V., Jambon, A., Johnson, R., Kallio, E., Killen, R., Lallement, R., Luhmann, J., Mendillo, M., Milillo, A., Palme, H., Potter, A., Sasaki, S., Slater, D., Sprague, A., Stern, A., and Yan, N.

Published
2010
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11. A High Speed, Radiation Hard X-Ray Imaging Spectroscometer for Planetary Investigations

Author

Kraft, R. P, Kenter, A. T, Murray, S. S, Martindale, A, Pearson, J, Gladstone, R, Branduardi-Raymont, G, Elsner, R, Kimura, T, Ezoe, Y, Grant, C, Roediger, E, Howell, R, Elvis, M, Smith, R, Campbell, B, Morgenthaler, J, Kravens, T, Steffl, A. J, and Hong, J

Subjects
Astronomy, Optics, Lunar And Planetary Science And Exploration
Abstract

X-ray observations provide a unique window into fundamental processes in planetary physics, and one that is complementary to observations obtained at other wavelengths. We propose to develop an X-ray imaging spectrometer (0.1-10 keV band) that, on orbital planetary missions, would measure the elemental composition, density, and temperature of the hot plasma in gas giant magnetospheres, the interaction of the Solar wind with the upper atmospheres of terrestrial planets, and map the elemental composition of the surfaces of the Galilean moons and rocky or icy airless systems on spatial scales as small as a few meters. The X-ray emission from gas giants, terrestrial planets and moons with atmospheres, displays diverse characteristics that depend on the Solar wind's interaction with their upper atmospheres and/or magnetospheres. Our imaging spectrometer, as part of a dedicated mission to a gas giant, will be a paradigm changing technology. On a mission to the Jovian system, our baseline instrument would map the elemental composition of the rocky and icy surfaces of the Galilean moons via particle-induced X-ray fluorescence. This instrument would also measure the temperature, density and elemental abundance of the thermal plasma in the magnetosphere and in the Io plasma torus (IPT), explore the interaction of the Solar wind with the magnetosphere, and characterize the spectrum, flux, and temporal variability of X-ray emission from the polar auroras. We will constrain both the mode of energy transport and the effective transport coefficients in the IPT and throughout the Jovian magnetosphere by comparing temporal and spatial variations of the X-ray emitting plasma with those seen from the cooler but energetically dominant 5 eV plasma.

Published
2014

12. Past and future polar amplification of climate change: climate model intercomparisons and ice-core constraints

Author

Masson-Delmotte, V., Kageyama, M., Braconnot, P., Charbit, S., Krinner, G., Ritz, C., Guilyardi, E., Jouzel, J., Abe-Ouchi, A., Crucifix, M., Gladstone, R. M., Hewitt, C. D., Kitoh, A., LeGrande, A. N., Marti, O., Merkel, U., Motoi, T., Ohgaito, R., Otto-Bliesner, B., Peltier, W. R., Ross, I., Valdes, P. J., Vettoretti, G., Weber, S. L., Wolk, F., and Yu, Y.

Published
2006
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13. Reorientation of Sputnik Planitia implies a subsurface ocean on Pluto

Author

Nimmo, F., Hamilton, D. P., McKinnon, W. B., Schenk, P. M., Binzel, R. P., Bierson, C. J., Beyer, R. A., Moore, J. M., Stern, S. A., Weaver, H. A., Olkin, C. B., Young, L. A., Smith, K. E., Spencer, J. R., Beyer, R., Buie, M., Buratti, B., Cheng, A., Cruikshank, D., Ore, C. Dalle, Earle, A., Gladstone, R., Grundy, W., Howard, A. D., Lauer, T., Linscott, I., Parker, J., Porter, S., Reitsema, H., Reuter, D., Roberts, J. H., Robbins, S., Showalter, M., Singer, K., Strobel, D., Summers, M., Tyler, L., White, O. L., Umurhan, O. M., Banks, M., Barnouin, O., Bray, V., Carcich, B., Chaikin, A., Chavez, C., Conrad, C., Howett, C., Hofgartner, J., Kammer, J., Lisse, C., Marcotte, A., Parker, A., Retherford, K., Saina, M., Runyon, K., Schindhelm, E., Stansberry, J., Steffl, A., Stryk, T., Throop, H., Tsang, C., Verbiscer, A., Winters, H., and Zangari, A.

Subjects
Pluto (Dwarf planet) -- Observations, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Author(s): F. Nimmo (corresponding author) [1]; D. P. Hamilton [2]; W. B. McKinnon [3]; P. M. Schenk [4]; R. P. Binzel [5]; C. J. Bierson [1]; R. A. Beyer [6]; [...]

Published
2016
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18. Overview of initial results from the reconnaissance flyby of a Kuiper Belt planetesimal: 2014 MU69

Author

Stern, S. A., Spencer, J. R., Weaver, H. A., Olkin, C. B., Moore, J. M., Grundy, W., Gladstone, R., McKinnon, W. B., Cruikshank, D. P., Young, L. A., Elliott, H. A., Verbiscer, A. J., Parker, J. Wm., and Team, the New Horizons

Subjects
Earth and Planetary Astrophysics (astro-ph.EP), FOS: Physical sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract

The centerpiece objective of the NASA New Horizons first Kuiper Extended Mission (KEM-1) was the close flyby of the Kuiper Belt Object KBO) 2014 MU69, nicknamed Ultima Thule. On 1 Jan 2019 this flyby culminated, making the first close observations of a small KBO. Initial post flyby trajectory reconstruction indicated the spacecraft approached to within ~3500 km of MU69 at 5:33:19 UT. Here we summarize the earliest results obtained from that successful flyby. At the time of this submission, only 4 days of data down-link from the flyby were available; well over an order of magnitude more data will be down-linked by the time of this Lunar and Planetary Science Conference presentation in 2019 March. Therefore many additional results not available at the time of this abstract submission will be presented in this review talk., 2 pages, 2 figures

Published
2019

19. Response of the Io plasma torus to comet Shoemaker-Levy 9

Author

McGrath, M.A., Hall, D.T., Matheson, P.L., Weaver, H.A., Trauger, J.T., Smith, T.E., Thomas, N., Gladstone, R., Schneider, N.M., Harris, W.M., Livengood, T.A., Prange, R., and Festou, M.C.

Subjects
Io (Satellite) -- Observations, Jupiter (Planet) -- Observations, Shoemaker-Levy 9 (Comet) -- Observations, Science and technology, Observations
Abstract

Spectroscopic and imaging observations of the lo plasma torus were made in June and July 1994 in conjunction with the encounter of periodic comet Shoemaker-Levy 9 with Jupiter. Characteristic emissions from sulfur and oxygen ions showed a decline of about 30 percent in the extreme ultraviolet and an increase of about 40 percent in the far ultraviolet relative to preimpact observations. Changes in the extreme ultraviolet may be indicative of small changes in the torus electron temperature as a result of quenching of electrons by dust associated with the comet passage. However, no new emission features indicative of fragment dust within the torus were detected. The characteristic torus morphology seen in ground-based imaging was typical of that observed in the past., An extensive program of observations was undertaken in July 1994 to determine what effect, if any, comet Shoemaker-Levy 9 (SL9) might have on the lo plasma torus. The torus is [...]

Published
1995

20. Chandra X-Ray Observatory Observations of the Jovian System

Author

Elsner, R. F, Bhardwaj, A, Gladstone, R, Waite, J. H, Ford, P, and Branduari-Raymont, G

Subjects
Astrophysics
Abstract

Chandra X-ray Observatory (CXO) and XMM-Newton observations of x-rays from the Jovian system have answered questions that arose from early observations with the Einstein and Rosat X-ray Observatories, but in the process of vastly increasing our knowledge of x-ray emission from Jupiter and its environs they have also raised new questions and point to new opportunities for future studies. We will review recent x-ray results on the Jovian system, from the point of view of the CXO, and discuss various questions that have arisen in the course of our studies. We will discuss prospects for more observations in the immediate future, and how they might address open questions. Finally we will briefly describe ways in which an imaging x-ray spectrometer in the vicinity of the Jovian system could provide a wealth of data and results concerning Jupiter's x-ray auroral and disk emission, elemental abundance measurements for the Galilean moons, and detailed studies of x-ray emission from the Io Plasma Torus.

Published
2005

21. A polar orbiter to probe Jupiter's deep atmosphere, interior structure and polar magnetosphere

Author

Bolton, S. J, Allison, M, Anderson, J, Atreya, S, Bagenal, F, Connerney, J, Coradini, A, DeJong, E, Folkner, W, Gautier, D, Gladstone, R, Gulkis, S, Guillot, T, Hofstadter, M, Hubbard, W, Ingersoll, A, Janssen, M, Klein, M, Kurth, W, Levin, S, Lunine, J, Mauk, B, McComas, D, Murphy, N, Owen, T, Smith, E, Spilker, T, Stevenson, D, Thorne, R, and Waite, H

Published
2003

22. Preliminary Results from Recent Simultaneous Chandra/HST Observations of Jupiter Auroral Zones

Author

Elsner, R, Gladstone, R, Waite, H, Majeed, T, Ford, P, Grodent, D, Bwardwaj, A, Howell, R, Cravens, T, and MacDowell, R

Subjects
Astronomy
Abstract

Jupiter was observed by the Chandra X-ray Observatory in late February, 2003, for 144 ks, using both the ACIS-S and HRC-I imaging x-ray cameras. Five orbits of HST STIS observations of the planet's northern auroral zone were obtained during the ACIS-S observations. These data are providing a wealth of information about Jupiter's auroral activity, including the first x-ray spectra from the x-ray hot spots inside the auroral ovals. We will also discuss the approximately 45 minute quasi-periodicity in the auroral x-ray emission - which correlates well with simultaneous observations of radio bursts by the Ulysses spacecraft - and a possible phase relation between the emission from the northern and southern x-ray aurora.

Published
2003

24. Electron and Proton Auroral Dynamics

Author

Mende, S. B, Frey, H. U, Gerard, J. C, Hubert, B, Fuselier, S, Spann, J. F., Jr, Gladstone, R, Burch, J. L, and Rose, M. Franklin

Subjects
Geophysics
Abstract

Data from the Wide-band Imaging Camera (WIC) sensitive to far ultraviolet auroras and from the Spectrographic Imager (SI) channel SI12, sensitive to proton precipitation induced Lyman alpha were analyzed during a high altitude orbit segment of the IMAGE spacecraft. This segment began during the expansive phase of a substorm. The aurora changed into a double oval configuration, consisting of a set of discrete pole-ward forms and a separate diffuse auroral oval equatorwards, Although IMF Bz was strongly southward considerable activity could be seen poleward of the discrete auroras in the region that was considered to be the polar cap. The SI12 Doppler shifted Lyman alpha signature of precipitating protons show that the proton aurora is on the equatorward side of the diffuse aurora. In the following several hours the IMF Bz field changed signed. Although the general character of the proton and electron aurora did not change, the dayside aurora moved equatorward when the Bz was negative and more bright aurora was seen in the central polar cap during periods of positive Bz.

Published
2000

25. The Proton and Electron Aurora as Seen by Image-FUV and FAST

Author

Gerard, J.-C, Hubert, B, Habraken, S, Renotte, E, Jamar, C, Rochus, P, Spann, J, Gladstone, R, and Rose, M. Franklin

Subjects
Geophysics
Abstract

The Far Ultraviolet (FUV) instrument on IMAGE images the aurora in three different wavelength regions. The Wideband Imaging Camera (WIC) observes the molecular Lyman-Birge-Hopfield (LBH) and atomic Nitrogen emissions at 140-190 nm. The two channels of the Spectrographic Imager (SI) observe the Doppler shifted Lyman Alpha emission of precipitating protons at 121.8 nm (SI 12) and the mostly electron produced emission from oxygen OI at 135.6 nm (SI13). The major advantage of FUV compared to previously flown UV imagers is the simultaneous operation of all three imaging systems without the need for filter changes and the uncertainty of temporal changes of the aurora between exposures. The FAST satellite passes every two hours through FUV images during apogee operations. This enables a comparison between the remotely imaged particle precipitation and the in-situ measurements along the FAST track. The detailed analysis of images from all three systems together with a full simulation of auroral emissions based on in-situ measurements by FAST confirms the laboratory calibrations of FUV. The spatial resolution and image quality of WIC permits the observation of a good correspondence between in-situ and remote measurements of precipitation boundaries. The clear separation between the lower latitude proton precipitation and the more structured higher latitude electron precipitation is obtained with both SI-channels.

Published
2000

26. Stellar Calibration of the WIC and SI Imagers and the GEO Photometers on IMAGE/FUV

Author

Gladstone, R, Mende, S. B, Frey, H. U, Geller, S. P, Immel, T. J, Lampton, M, Gerard, J.-C, Spann, J, Habraken, S, Renotte, E, Jamar, C, Rochus, P, and Rose, M. Franklin

Subjects
Optics
Abstract

The FUV instrument on the IMAGE spacecraft comprises three wide-field imagers, the Wide-Band Imaging Camera (WIC) of observing N2 Lyman-Birge-Hopfield (LBH) (140-190 nm) emissions and the Spectrographic Imager (SI), which has a 121.8 nm channel for observing red-shifted HI Lya photons and a 135.6 run channel for observing 01 135.6 nm emissions. In addition, three HI Lya photometers (GEO) are used to monitor the geocorona. The fields of view are 17 degrees x 17 degrees for the WIC imagers, 15 degrees x 15 degrees for the two SI imagers, and 10 diameter for the three GEO photometers. As the IMAGE spacecraft spins every 120 seconds, the GEO photometers sweep out circles on the sky (at 0 degrees and plus or minus 30 degrees with respect to the spacecraft spin plane), and the WIC and SI imagers use the Time Delay Integration (TDI) method to construct images centered on the Earth. Many FUV-bright stars are seen in the WIC, SI and even the GEO data. WE have used archived International Ultraviolet Explorer (IUE) far-ultraviolet flux spectra for 22 of the brightest of these stars to help refine the FUV instrumental sensitivities. The stars chosen range in spectral type form B0V to A11V, with magnitudes ranging from V- 1.3 (a Cru) to V=4.7 (G Cen) (although many more fainter stars are also seen). The initial results of this stellar calibration will be presented and compared with the pre-flight and dayglow modeling results.

Published
2000

27. Rocket FUV Observations of the Io Plasma Torus During the Shoemaker-Levy/9 Impacts

Author

Stern, S. A, Slater, D, Cash, W, Wilkinson, E, Green, J, and Gladstone, R

Subjects
Lunar And Planetary Exploration
Abstract

We observed the Io torus from 820-1140 A on universal time (UT) 20.25 July 1994 from a sounding rocket telescope/spectrograph. These observations serve as only the fourth published spectrum of the torus in this wavelength range, and the only far ultraviolet (FUV) data documenting the state of the torus during the Shoemaker Levy 9 Impacts.

Published
1995
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28. Population genetic structure, antibiotic resistance, capsule switching and evolution of invasive pneumococci before conjugate vaccination in Malawi

Author

Chaguza, C, Cornick, J, Andam, C, Gladstone, R, Alaerts, M, Musicha, P, Peno, C, Bar-Zeev, N, Kamng'ona, A, Kiran, A, Msefula, C, McGee, L, Breiman, R, Kadioglu, A, French, N, Heyderman, R, Hanage, W, Bentley, S, and Everett, D

Subjects
Research Support, Non-U.S. Gov't, Journal Article, Human medicine
Abstract

Introduction: Pneumococcal infections cause a high death toll in Sub Saharan Africa (SSA) but the recently rolled out pneumococcal conjugate vaccines (PCV) will reduce the disease burden. To better understand the population impact of these vaccines, comprehensive analysis of large collections of pneumococcal isolates sampled prior to vaccination is required. Here we present a population genomic study of the invasive pneumococcal isolates sampled before the implementation of PCV13 in Malawi. Materials and methods: We retrospectively sampled and whole genome sequenced 585 invasive isolates from 2004 to 2010. We determine the pneumococcal population genetic structure and assessed serotype prevalence, antibiotic resistance rates, and the occurrence of serotype switching. Results: Population structure analysis revealed 22 genetically distinct sequence clusters (SCs), which consisted of closely related isolates. Serotype 1 (ST217), a vaccine-associated serotype in Glade SC2, showed highest prevalence (19.3%), and was associated with the highest MDR rate (81.9%) followed by serotype 12F, a non-vaccine-serotype in Glade SC10 with an MDR rate of 57.9%. Prevalence of serotypes was stable prior to vaccination although there was an increase in the PMEN19 clone, serotype 5 ST289, in Glade SC1 in 2010 suggesting a potential undetected local outbreak. Coalescent analysis revealed recent emergence of the SCs and there was evidence of natural capsule switching in the absence of vaccine induced selection pressure. Furthermore, majority of the highly prevalent capsule-switched isolates were associated with acquisition of vaccine-targeted capsules. Conclusions: This study provides descriptions of capsule-switched serotypes and serotypes with potential to cause serotype replacement post-vaccination such as 12F. Continued surveillance is critical to monitor these serotypes and antibiotic resistance in order to design better infection prevention and control measures such as inclusion of emerging replacement serotypes in future conjugate vaccines. (C) 2017 The Authors. Published by Elsevier Ltd.

Published
2017
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29. Hot flow anomaly observed at Jupiter's bow shock

Author

Valek, P. W., Thomsen, M. F., Allegrini, F., Bagenal, F., Bolton, S., Connerney, J., Ebert, R. W., Gladstone, R., Kurth, W. S., Levin, S., Louarn, P., Mauk, B., Mccomas, D. J., Pollock, C., Reno, M., Szalay, J. R., Weidner, S., Wilson, R. J., Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)

Subjects
Juno, Bow shock, [SDU]Sciences of the Universe [physics], Jupiter, Hot flow anomaly
Abstract

International audience; A Hot Flow Anomaly (HFA) is created when an interplanetary current sheet interacts with a planetary bow shock. Previous studies have reported observing HFAs at Earth, Mercury, Venus, Mars, and Saturn. During Juno's approach to Jupiter, a number of its instruments operated in the solar wind. Prior to crossing into Jupiter's magnetosphere, Juno observed an HFA at Jupiter for the first time. This Jovian HFA shares most of the characteristics of HFAs seen at other planets. The notable exception is that the Jovian HFA is significantly larger than any HFA seen before. With an apparent size greater than 2 × 106 km the Jovian HFA is orders of magnitude larger than those seen at the other planets. By comparing the size of the HFAs at the other planets with the Jovian HFA, we conclude that HFAs size scales with the size of planetary bow shocks that the interplanetary current sheet interacts with.

Published
2017
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31. Atmospheric and Oceanographic Signatures in the Ice Shelf Channel Morphology of Roi Baudouin Ice Shelf, East Antarctica, Inferred From Radar Data.

Author

Drews, R., Schannwell, C., Ehlers, T. A., Gladstone, R., Pattyn, F., and Matsuoka, K.

Subjects
OCEANOGRAPHY, ANTARCTIC research stations, STRATIGRAPHIC geology, FLOTATION, ROI Baudouin Station (Antarctica)
Abstract

Ice shelves around Antarctica can provide back stress for outlet glaciers and control ice sheet mass loss. They often contain narrow bands of thin ice termed ice shelf channels. Ice shelf channel morphology can be interpreted through surface depressions and exhibits junctions and deflections from flowlines. Using ice flow modeling and radar, we investigate ice shelf channels in the Roi Baudouin Ice Shelf. These are aligned obliquely to the prevailing easterly winds. In the shallow radar stratigraphy, syncline and anticline stacks occur beneath the upwind and downwind side, respectively. The structures are horizontally and vertically coherent, except near an ice shelf channel junction where patterns change structurally with depth. Deeper layers truncate near basal incisions. Using ice flow modeling, we show that the stratigraphy is ∼9 times more sensitive to atmospheric variability than to oceanic variability. This is due to the continual adjustment toward flotation. We propose that syncline‐anticline pairs in the shallow stratigraphy are caused by preferential snow deposition on the windward side and wind erosion at the downwind side. This drives downwind deflection of ice shelf channels of several meters per year. The depth variable structures indicate formation of an ice shelf channel junction by basal melting. We conclude that many ice shelf channels are seeded at the grounding line. Their morphology farther seaward is shaped on different length scales by ice dynamics, the ocean, and the atmosphere. These processes act on finer (subkilometer) scales than are captured by most ice, atmosphere, and ocean models, yet the dynamics of ice shelf channels may have broader implications for ice shelf stability. Plain Language Summary: Ice flows from Antarctica's interior toward the coast. At the contact point between ice and ocean, the ice becomes afloat and forms fast‐flowing ice shelves. Snowfall continuously accumulates at the ice shelf surface, and at the ice shelf bottom the relatively warm ocean water can melt ice from below. Ice shelves sometimes exhibit a network of surface depressions resembling a river network. At the base, the depressions are accompanied by large incisions termed ice shelf channels. Using radar as a tool for echolocation, we investigate how the shape of this network is formed. We find that snow preferentially collects in the upwind side of the surface depressions. This makes ice shelf channels move to the downwind side. We also find that ice shelf channels can form junctions through localized ocean melting. This is important because it helps us to better understand how the Antarctic ice sheet interacts with the surrounding ocean. Key Points: The radar stratigraphy in ice shelves is 9 times more sensitive to variability in snow deposition than to variability in basal meltingSome ice shelf channels at Roi Baudouin Ice Shelf deflect from flowlines; the radar stratigraphy reflects related processesVariable snow deposition causes slow deflection, and basal melting can form ice shelf channel junctions far from the grounding line [ABSTRACT FROM AUTHOR]

Published
2020
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34. Discussion On Giants And Dwarfs

Author

Cunningham, D. J., Windle, B. C. A., Gilford, Hastings, Gibson, George A., Dixon, A. F., Thompson, Peter, Mann, Gustav, Gladstone, R. J., Anderson, Richard J., Patten, C. J., and Symington, Johnson

Published
1904

36. Jupiter Icy Moons Explorer: mission status after the Definition Phase

Author

Titov, D., Barabash, S., Bruzzone, Lorenzo, Dougherty, M. K., Erd, C., Fletcher, L., Gare, Philippe, Gladstone, R., Grasset, O., Gurvits, L., Hartogh, P., Hussmann, Hauke, Iess, L., Jaumann, Ralf, Langevin, Yves, Palumbo, P., Piccioni, Giuseppe, Sarri, Guiseppe, Wahlund, J.-E., and Witasse, Olivier

Subjects
Planetengeologie, Planetengeodäsie, JUICE
Published
2015

37. Century-scale simulations of the response of the West Antarctic Ice Sheet to a warming climate

Author

Cornford, S. L., Martin, D. F., Payne, A. J., Ng, E. G., Le Brocq, A. M., Gladstone, R. M., Edwards, T. L., Shannon, S. R., Agosta, C., van den Broeke, M. R., Hellmer, H. H., Krinner, G., Ligtenberg, S. R. M., Timmermann, R., Vaughan, D. G., Sub Dynamics Meteorology, Marine and Atmospheric Research, University of Bristol [Bristol], Lawrence Berkeley National Laboratory [Berkeley] (LBNL), Centre for Ecology and Conservation, College of Life and Environmental Sciences, University of Exeter, Penryn, UK., Université de Liège, Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Institute for Marine and Atmospheric Research [Utrecht] (IMAU), Utrecht University [Utrecht], Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), School of Geographical Sciences, University of Bristol, Bristol, United Kingdom, Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Lawrence Berkeley National Laboratory [Berkeley] ( LBNL ), University of Liege Belgium, Laboratoire de glaciologie et géophysique de l'environnement ( LGGE ), Observatoire des Sciences de l'Univers de Grenoble ( OSUG ), Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Université Joseph Fourier - Grenoble 1 ( UJF ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université Grenoble Alpes ( UGA ) -Centre National de la Recherche Scientifique ( CNRS ), Institute for Marine and Atmospheric Research Utrecht ( IMAU ), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung ( AWI ), Institute for Marine and Atmospheric Research Utrecht, British Antarctic Survey ( BAS ), Natural Environment Research Council ( NERC ), Sub Dynamics Meteorology, and Marine and Atmospheric Research

Subjects
SHELF, 010504 meteorology & atmospheric sciences, SURFACE MASS-BALANCE, Ice stream, FLOW, MODELS, Antarctic ice sheet, Antarctic sea ice, 010502 geochemistry & geophysics, 01 natural sciences, Ice shelf, [ SDE ] Environmental Sciences, Sea ice, Cryosphere, Ice divide, BED, lcsh:Environmental sciences, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, lcsh:GE1-350, geography, geography.geographical_feature_category, lcsh:QE1-996.5, WEDDELL SEA SECTOR, RETREAT, lcsh:Geology, GROUNDING-LINE MIGRATION, 13. Climate action, Climatology, [SDE]Environmental Sciences, PINE ISLAND GLACIER, Ice sheet, SENSITIVITY, Geology
Abstract

We use the BISICLES adaptive mesh ice sheet model to carry out one, two, and three century simulations of the fast-flowing ice streams of the West Antarctic Ice Sheet. Each of the simulations begins with a geometry and velocity close to present day observations, and evolves according to variation in meteoric ice accumulation, ice shelf melting, and mesh resolution. Future changes in accumulation and melt rates range from no change, through anomalies computed by atmosphere and ocean models driven by the E1 and A1B emissions scenarios, to spatially uniform melt rates anomalies that remove most of the ice shelves over a few centuries. We find that variation in the resulting ice dynamics is dominated by the choice of initial conditions, ice shelf melt rate and mesh resolution, although ice accumulation affects the net change in volume above flotation to a similar degree. Given sufficient melt rates, we compute grounding line retreat over hundreds of kilometers in every major ice stream, but the ocean models do not predict such melt rates outside of the Amundsen Sea Embayment until after 2100. Sensitivity to mesh resolution is spurious, and we find that sub-kilometer resolution is needed along most regions of the grounding line to avoid systematic under-estimates of the retreat rate, although resolution requirements are more stringent in some regions – for example the Amundsen Sea Embayment – than others – such as the Möller and Institute ice streams.

Published
2015
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38. The Jupiter icy moons explorer (JUICE): Complementarity of the payload in addressing the mission science objectives (abstract)

Author

Grasset, O., Altobelli, N., Barabash, S., Bruzzone, L., Dougherty, M., Erd, C., Fletcher, L., Gare, P., Gladstone, R., Gurvits, L., Hartogh, P., Hussmann, H., Jaumann, R., Iess, L., Langevin, Y., Palumbo, P., Piccioni, G., Titov, D., and Wahlund, J.E.

Abstract

This presentation will give a status of the JUICE mission in the end of the definition phase, its science scenario, and the observation strategies that are foreseen with a strong emphasis on the complemen-tarity of the suite of instruments. To summarize, the instrument suite on-board JUICE will allow the inte-gration of datasets into a comprehensive multisensor / multitemporal / multiresolution view maximizing the scientific return of the data. This will be demonstrated using six examples that are briefly described in this abstract.

Published
2014

39. Jupiter Icy Moons Explorer (JUICE): Science Objectives, Mission and Instruments (abstract)

Author

Gurvits, L., Plaut, J.J., Barabash, S., Bruzzone, L., Dougherty, M., Erd, C., Fletcher, L., Gladstone, R., Grasset, O., Hartogh, P., Hussmann, H., Iess, L., Jaumann, R., Langevin, Y., Palumbo, P., Piccioni, G., Titov, D., and Wahlund, J.E.

Subjects
Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Physics::Geophysics
Abstract

The JUpiter ICy Moons Explorer (JUICE) is a European Space Agency mission that will fly by and observe the Galilean satellites Europa, Ganymede and Callisto, characterize the Jovian system in a lengthy Jupiter-orbit phase, and ultimately orbit Ganymede for in-depth studies of habitability, evolution and the local environment [1].

Published
2014

40. Jupiter Icy Moons Explorer (JUICE): Science Objectives, Mission and Instruments

Author

Plaut, S., Barabash, S., Bruzzone, L., Dougherty, M. K., Erd, C., Fletcher, L., Gladstone, R., Grasset, O., Gurvits, L., Hartogh, Paul, Hussmann, H., Iess, L., Jaumann, R., Langevin, Y., Palumbo, P., Piccioni, G., Titov, D.V., and Wahlund, J.-E.

Subjects
Planetengeologie, Juice, planetary missions, Planetengeodäsie
Published
2014

41. JUICE:complementarity of the payload in adressing the mission science objectives

Author

Titov, D.V., Barabash, S., Bruzzone, L., Dougherty, M. K., Erd, C., Fletcher, L., Gare, Philippe, Gladstone, R., Grasset, O., Gurvits, L., Hartogh, P., Hussmann, H., Iess, L., Jaumann, R., Langevin, Y., Palumbo, P., Piccioni, G., and Wahlund, J.-E.

Subjects
Planetengeologie, Planetengeodäsie, JUICE
Published
2014

43. Assessing Quasi‐Periodicities in Jovian X‐Ray Emissions: Techniques and Heritage Survey.

Author

Jackman, C. M., Knigge, C., Altamirano, D., Gladstone, R., Dunn, W., Elsner, R., Kraft, R., Branduardi‐Raymont, G., and Ford, P.

Subjects
MONTE Carlo method, FAST Fourier transforms, AURORAL zones, RAYLEIGH waves, BIG data
Abstract

Jupiter's auroral X‐rays are rather mysterious, with an unknown driver, and several previous reports of individual cases of quasi‐periodic emission. In this work we revisit heritage X‐ray data sets from the 1990s to 2015 and apply robust significance testing of emerging quasi‐periodicities, seeking to understand the robustness and regularity of previously reported quasi‐periodic emissions. Our analysis incorporates the use of the Rayleigh test as an alternative to Lomb‐Scargle analysis or Fast Fourier Transforms, where Rayleigh is particularly suited to a time‐tagged data set of sparse counts such as is common for jovian X‐ray data. Furthermore, the analysis techniques that we present (including Rayleigh testing and Monte Carlo simulation) can be applied to any time‐tagged data set. The code to conduct such analysis is released as supplementary information to accompany this paper. The five most significant (p value <0.01) quasi‐periods from Jupiter's northern auroral region have periods ranging from ~8.0 to 45.96 min, and the two most significant (p value <0.01) quasi‐periods from the south have periods of ~14.1 and ~34.9 min. The selection of a restrictive hot spot source region seems to be critical for detecting quasi‐periodic emission, suggesting that the site of pulsations may be spatially localized. Periods vary from one Jupiter rotation to the next in one long observation, and the north and south are shown to pulse independently in another conjugate observation. These results have important implications for understanding the driver of jovian X‐ray emission. Key Points: Timing analysis of Chandra observations of Jupiter's X‐ray auroras from 1999 to 2015Statistically significant quasi‐periodicities in jovian auroral X‐rays are relatively rare and periods variable, even on successive planetary rotationsWe use Rayleigh testing and Monte Carlo simulation to search for statistically significant quasi‐periods in sparse, time‐tagged data [ABSTRACT FROM AUTHOR]

Published
2018
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44. Earth-based detection of Uranus' aurorae

Author

Lamy, L., Prangé, R., Hansen, K., Clarke, J., Zarka, P., Cecconi, B., Aboudarham, J., Andre, N., Branduardi-Raymont, G., Gladstone, R., Barthelemy, M., Achilleos, N., Guio, P., Dougherty, M., Melin, H., Cowley, S., Stallard, T., Nichols, J., Ballester, G., AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG ), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Department of Physics and Astronomy [UCL London], Space and Atmospheric Physics Group [London], Blackett Laboratory, Imperial College London-Imperial College London, Université de Lille, Radio and Space Plasma Physics Group [Leicester] (RSPP), University of Leicester, University of Edinburgh, Department of Planetary Sciences [Tucson], University of Arizona, Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), and Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)

Subjects
[PHYS]Physics [physics], [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2012
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45. Grounding line migration in an adaptive mesh ice sheet model

Author

Gladstone, R M, Lee, V, Vieli, Andreas, Payne, A J, and University of Zurich

Subjects
1104 Aquatic Science, 1901 Earth and Planetary Sciences (miscellaneous), 1904 Earth-Surface Processes, 1107 Forestry, 1911 Paleontology, 10122 Institute of Geography, 2312 Water Science and Technology, 1912 Space and Planetary Science, 1910 Oceanography, 1902 Atmospheric Science, 1906 Geochemistry and Petrology, 910 Geography & travel, 1908 Geophysics, 2303 Ecology, 1111 Soil Science
Published
2010

46. Past polar amplification of climate change : assessment of PMIP climate model intercomparisons and ice-core constraints

Author

Masson-Delmotte, Valérie, Kageyama, Masa, Braconnot, Pascale, Charbit, S., Krinner, Gerhard, Ritz, C., Guilyardi, Éric, Jouzel, Jean, Abe-Ouchi, Ayako, Crucifix, M., M. Gladstone, R., D. Hewitt, C., Kitoh, A., N. Legrande, A., Marti, Olivier, Merkel, U., Motoi, T., Ohgaito, R., Otto-Bliesner, B., R. Peltier, W., Ross, I., J. Valdes, P., Vettoretti, G., L. Weber, S., Wolk, F., Yu, Y., Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de glaciologie et géophysique de l'environnement (LGGE), Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Joseph Fourier - Grenoble 1 (UJF)-Observatoire des Sciences de l'Univers de Grenoble [1985-2015] (OSUG [1985-2015]), and Université Joseph Fourier - Grenoble 1 (UJF)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut polytechnique de Grenoble - Grenoble Institute of Technology [2007-2019] (Grenoble INP [2007-2019])-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)

Subjects
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [PHYS.PHYS.PHYS-GEO-PH]Physics [physics]/Physics [physics]/Geophysics [physics.geo-ph]
Abstract

Climate model simulations available from the PMIP1, PMIP2 and CMIP (IPCC-AR4) intercomparison projects for past and future climate change simulations are examined in terms of polar temperature changes in comparison to global temperature changes and with respect to pre-industrial reference simulations. For the mid-Holocene (MH, 6,000 years ago), the models are forced by changes in the Earth's orbital parameters. The MH PMIP1 atmosphere-only simulations conducted with sea surface temperatures fixed to modern conditions show no MH consistent response for the poles, whereas the new PMIP2 coupled atmosphere–ocean climate models systematically simulate a significant MH warming both for Greenland (but smaller than ice-core based estimates) and Antarctica (consistent with the range of ice-core based range). In both PMIP1 and PMIP2, the MH annual mean changes in global temperature are negligible, consistent with the MH orbital forcing. The simulated last glacial maximum (LGM, 21,000 years ago) to pre-industrial change in global mean temperature ranges between 3 and 7°C in PMIP1 and PMIP2 model runs, similar to the range of temperature change expected from a quadrupling of atmospheric CO2 concentrations in the CMIP simulations. Both LGM and future climate simulations are associated with a polar amplification of climate change. The range of glacial polar amplification in Greenland is strongly dependent on the ice sheet elevation changes prescribed to the climate models. All PMIP2 simulations systematically underestimate the reconstructed glacial–interglacial Greenland temperature change, while some of the simulations do capture the reconstructed glacial–interglacial Antarctic temperature change. Uncertainties in the prescribed central ice cap elevation cannot account for the temperature change underestimation by climate models. The variety of climate model sensitivities enables the exploration of the relative changes in polar temperature with respect to changes in global temperatures. Simulated changes of polar temperatures are strongly related to changes in simulated global temperatures for both future and LGM climates, confirming that ice-core-based reconstructions provide quantitative insights on global climate changes.

Published
2006
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47. Planetary Ionospheres And Magnetospheres: What Can We Learn From Comparative Auroral Analysis?

Author

Galand, Marina, Prangé, Renée, Bhardwaj, Anil, Chakrabarti, Supriya, Gladstone, R., Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Physique des plasmas, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2005

49. Jupiter's Auroral Infrared Emissions from FTS/BEAR Spectro-imaging Observations

Author

Maillard, Jean-Pierre, Lellouch, Emmanuel, Fouchet, Thierry, Drossart, Pierre, Bézard, Bruno, Waite, Hunter, Gladstone, R., Mandin, J.-Y., Dana, V., Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)

Subjects
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Abstract

International audience

Published
2002

50. Impact of ocean forcing on the Aurora Basin in the 21st and 22nd centuries.

Author

Sun, S., Cornford, S. L., Gwyther, D. E., Gladstone, R. M., Galton-Fenzi, B. K., Zhao, L., and Moore, J. C.

Subjects
ICE shelves, GEOLOGICAL basins, MARINE ecology, OCEANOGRAPHY
Abstract

The grounded ice in the Totten and Dalton glaciers is an essential component of the buttressing for the marine-based Aurora basin, and hence their stability is important to the future rate of mass loss from East Antarctica. Totten and Vanderford glaciers are joined by a deep east-west running subglacial trench between the continental ice sheet and Law Dome, while a shallower trench links the Totten and Dalton glaciers. All three glaciers flow into the ocean close to the Antarctic circle and experience ocean-driven ice shelf melt rates comparable with the Amundsen Sea Embayment. We investigate this combination of trenches and ice shelves with the BISICLES adaptive mesh ice-sheet model and ocean-forcing melt rates derived from two global climate models. We find that ice shelf ablation at a rate comparable with the present day is sufficient to cause widespread grounding line retreat in an east-west direction across Totten and Dalton glaciers, with projected future warming causing faster retreat. Meanwhile, southward retreat is limited by the shallower ocean facing slopes between the coast and the bulk of the Aurora sub-glacial trench. However the two climate models produce completely different future ice shelf basal melt rates in this region: HadCM3 drives increasing sub-ice shelf melting to ~2150, while ECHAM5 shows little or no increase in sub-ice shelf melting under the two greenhouse gas forcing scenarios. [ABSTRACT FROM AUTHOR]

Published
2016
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