Search

Your search keyword '"Esposito, L. W"' showing total 14 results
Start Over Author "Esposito, L. W" Publication Year Range Last 10 years
14 results on '"Esposito, L. W"'

3. Enhanced Airglow Signature Observed at Titan in Response to its Fluctuating Magnetospheric Environment

Author

Royer, E. M., Esposito, L. W., Crary, F., Wahlund, Jan-Erik, Royer, E. M., Esposito, L. W., Crary, F., and Wahlund, Jan-Erik

Abstract

On rare occasions Titan has been observed in the magnetosheath, where the solar wind interferes with the regular magnetic field generated by Saturn. This particular orbital position allows for a deeper investigation of Titan's upper atmosphere response to its highly energetic magnetospheric environment. Although solar extreme ultraviolet radiation is known to be the main source of ionization in Titan's upper atmosphere, magnetospheric particle precipitation can also account for about 10% of the ionization process. We are reporting here on ultraviolet observations of Titan airglow enhancements occurring while the spacecraft and Titan are known to have been exposed to the magnetosheath environment. Using remote sensing Cassini Ultraviolet Imaging Spectrograph observations of Titan in correlation with in situ Cassini Plasma Spectrometer measurements, we present evidence of Titan's upper atmosphere response to an electron burst crossing the magnetosheath at the time of the T32 flyby, on 13 June 2007. Plain Language Summary Most of the time, Titan is embedded in Saturn's magnetosphere. The solar wind pressure on Saturn's magnetic field defines the size of the magnetospheric envelop around the planet. On rare occasion, this pressure is strong enough to reduce the size of Saturn's magnetospheric envelop, leaving Titan outside of it. We have been observing Titan and its immediate environment during such a configuration. The compression of the magnetic envelop allows for Titan uppermost layer of its atmosphere to directly interact with solar wind particles. We are reporting here on an observation showing a strong and sudden brightening of the upper atmosphere of Titan correlated with simultaneous measurements of an increase in electron energy around the satellite. Using remote sensing Cassini Ultraviolet Imaging Spectrograph observations of Titan in correlation with in situ Cassini Plasma Spectrometer measurements, we present evidence of Titan's upper atmosphere response to

Published
2018
Full Text
View/download PDF

8. The Clouds of Venus – an overview of Venus Express results

Author

Wilson, C. F., Marcq, Emmanuel, Markiewicz, W.J., Montmessin, Franck, Fedorova, A., Wilquet, V., Petrova, E.V., Ignatiev, N.I., Shalygina, O.S., Määttänen, Anni, McGouldrick, K.M., Hashimoto, G.L., Imamura, T., Rossi, Loïc, Luginin, M., Oschlisniok, J., Haus, R., Parkinson, C.D., Titov, D.V., Esposito, L. W., Limaye, Sanjay S., Vandaele, A.-C., Zasova, Liudmila V., Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), University of Oxford [Oxford], IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Space Research Institute of the Russian Academy of Sciences ( IKI ), Russian Academy of Sciences [Moscow] ( RAS ), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] ( IGEP ), Technische Universität Braunschweig [Braunschweig], Laboratory for Atmospheric and Space Physics [Boulder] ( LASP ), University of Colorado Boulder [Boulder], Okoyama University, Institute of Space and Astronautical Science ( ISAS ), Rhenish Institute for Environmental Research ( RIU ), University of Cologne, Westfälische Wilhelms-Universität Münster ( WWU ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), University of Michigan [Ann Arbor], European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ), Space Science and Engineering Center [Madison] ( SSEC ), University of Wisconsin-Madison [Madison], Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Okayama University, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), Rhenish Institute for Environmental Research (RIU), Westfälische Wilhelms-Universität Münster = University of Münster (WWU), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan System-University of Michigan System, European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Space Science and Engineering Center [Madison] (SSEC), University of Wisconsin-Madison, Max-Planck-Institut für Sonnensystemforschung (MPS), Westfälische Wilhelms-Universität Münster (WWU), and European Space Agency (ESA)

Subjects
[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP]
Abstract

International audience; Venus is completely enveloped by clouds. The main cloud layers stretch from altitudes of 48 – 75 km, with additional tenuous hazes found at altitudes 30 – 100 km. Clouds play a crucial role in governing atmospheric circulation, chemistry and climate on all planets, but particularly so on Venus due to the optical thickness of the atmosphere. The European Space Agency’s Venus Express (VEx) satellite has carried out a wealth of observations of Venus clouds since its arrival at Venus in April 2006. Many VEx observations are relevant to cloud science – from imagers and spectrometers to solar, stellar and radio occultation – each covering different altitude ranges, spectral ranges and atmospheric constituents.We have formed an International Team at the International Space Science Institute to bring together scientists from each of the relevant Venus Express investigation teams as well as from previous missions, as well as those developing computational and analytical models of clouds and hazes. The aims of the project are (1) to perform intercomparisons of cloud parameters measured using different techniques, (1) to create self-consistent reference cloud/haze models which capture not only a mean cloud structure but also its main modes of variability; and (2) to bring together modelers and observers, to reach an understanding of clouds and hazes on Venus which matches all observables and is physically consistent.This talk will present an overview of Venus Express cloud observations of all different types, and discuss progress towards a new reference cloud model to be submitted to an update of the Venus International Reference Atmosphere.

Published
2015

10. The Search for Activity on Dione and Tethys With CassiniVIMS and UVIS

Author

Buratti, B. J., Hansen, C. J., Hendrix, A. R., Esposito, L. W., Mosher, J. A., Brown, R. H., Clark, R. N., Baines, K. H., and Nicholson, P. D.

Abstract

During the Cassinimission the Saturnian moons Dione and Tethys showed intriguing and multiple clues suggesting residual geologic activity that might be detectable as an atmosphere, plume, or even heat signature. These clues included an atmospheric aura around Dione, injection of particles into Saturn's magnetosphere, mysterious red streaks on Tethys, and possible cryovolcanic features on Dione. A concerted effort that was strengthened in the latter stages of the mission included the acquisition of stellar occulations by the Ultraviolet Imaging Spectrograph (UVIS) of both Dione and Tethys and high solar phase observations of Dione by the Visible Infrared Mapping Spectrometer (VIMS) to detect forward scattering from grains in a plume. Analysis of these observations shows no evidence for even a low level of activity on either moon. In addition, infrared images at 2.65 μm obtained throughout the mission were scrutinized for the reappearance of an atmosphere‐like aura, with negative results. Two moons of Saturn, Dione and Tethys, showed intriguing clues suggesting residual geologic activity on their surfaces throughout the Cassinimission. A close inspection of data from the ultraviolet and visible/infrared imagers on Cassini failed to detect an atmosphere or plume on either moon. Dione and to a less extent Tethys exhibited clues during the Cassinimission for residual geological activityOccultations and images from the ultraviolet and visible/infrared imaging spectrometers showed no evidence for a plume or atmosphere on either moon

Published
2018
Full Text
View/download PDF

12. ENCELADUS: USING UV DATA TO STUDY PLUME FALLOUT.

Author

Hendrix, A. R., Hansen, C. J., Royer, E. M., Cassidy, T. A., Esposito, L. W., and Holsclaw, G. M.

Subjects
ENCELADUS (Satellite), SATELLITES of Saturn, SPACE exploration
Published
2017

Catalog

Books, media, physical & digital resources
See catalog results