30 results on '"Jain, Sonal K."'
Search Results
2. Another one derives the dust: Ultraviolet dust aerosol properties retrieved from MAVEN/IUVS data
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Connour, Kyle, Wolff, Michael J., Schneider, Nicholas M., Deighan, Justin, Lefèvre, Franck, and Jain, Sonal K.
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- 2022
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3. MAVEN/IUVS observations of C I 156.1 nm and 165.7 nm dayglow: Direct detection of carbon and implications on photochemical escape
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Lo, Daniel Y., Yelle, Roger V., Deighan, Justin I., Jain, Sonal K., Evans, J. Scott, Stevens, Michael H., Ajello, Joseph M., Mayyasi, Majd A., and Schneider, Nicholas M.
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- 2022
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4. EMM EMUS Observations of FUV Aurora on Mars: Dependence on Magnetic Topology, Local Time, and Season.
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Chirakkil, Krishnaprasad, Lillis, Robert J., Deighan, Justin, Chaffin, Michael S., Jain, Sonal K., Brain, David A., Fillingim, Matthew O., Susarla, Raghuram, Holsclaw, Greg, Fang, Xiaohua, Schneider, Nick M., AlMazmi, Hoor, AlMatroushi, Hessa, Gacesa, Marko, El‐Kork, Nayla, Thiemann, Ed, and Halekas, Jasper S.
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THERMOSPHERE ,AURORAS ,SPACE environment ,CORONAL mass ejections ,MARS (Planet) ,SOLAR cycle - Abstract
We present a comprehensive study of the nightside aurora phenomenon on Mars, utilizing observations from EMUS onboard Emirates Mars Mission. The oxygen emission at 130.4 nm is by far the brightest FUV auroral emission line observed at Mars. Our statistical analysis reveals geographic, solar zenith angle, local time, and seasonal dependencies of auroral occurrence. Higher occurrence of aurora is observed in regions of open magnetic topology, where crustal magnetic fields are either very weak or both strong and vertical. Aurora occurs more frequently closer to the terminator and is more likely on the dusk side than on the dawn side of the night hemisphere. A pronounced auroral feature appears close to midnight local times in the southern hemisphere, consistent with the spot of energetic electron fluxes previously identified in the Mars Global Surveyor data. This auroral spot is more frequent after midnight than before. Additionally, some regions on Mars are "aurora voids" where essentially no aurora occurs. Aurora exhibits a seasonal dependence, with a major enhancement near perihelion. Non–crustal field aurora additionally shows a secondary enhancement near Ls 30°. This seasonal variability is a combination of the variability in ionospheric photoelectrons and thermospheric atomic oxygen abundance. Auroral occurrence also shows an increase with the rise of Solar Cycle 25. The brightest auroral pixels are observed during space weather events such as Coronal Mass Ejections and Stream Interaction Regions. These observations not only shed light on where and when Martian aurora occurs, but also add to our understanding of Mars' magnetic environment and its interaction with the heliosphere. Plain Language Summary: In this study, we explore the phenomenon of aurora on the nightside of Mars, using observations from the highly sensitive Emirates Mars Ultraviolet Spectrometer (EMUS) on the Emirates Mars Mission. Our analysis reveals distinct patterns in auroral occurrence on the planet. For instance, there is a higher rate of auroral activity in regions where Mars' magnetic field lines are open (i.e., connected to the collisional atmosphere at one end). We also found that aurora is more common near the terminator (with the occurrence decreasing as the solar zenith angle increases), and particularly during the evening hours, as opposed to early morning. Interestingly, these auroral events also show a seasonal dependence, peaking around perihelion in a Martian year, when Mars is closest to the sun. This seasonal pattern corresponds with the variation of photoelectrons in Mars' dayside ionosphere and the atomic oxygen abundance in the thermosphere. Auroral occurrence increases with increasing solar activity. Also, the auroral brightness increases during space weather events. Our study not only gives us a clearer picture of where and when the aurora occurs on Mars but also hints at the underlying processes influencing them, offering insights into the planet's magnetic and charged particle environment. Key Points: Higher auroral occurrence is observed in regions of open magnetic topology, where crustal fields are either very weak or primarily verticalAurora occurs more frequently near the terminator compared to deep night, with higher occurrence at dusk than at dawnAurora occurs more frequently near perihelion, with the brightest auroral pixels observed during space weather events [ABSTRACT FROM AUTHOR]
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- 2024
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5. The Emirates Mars Ultraviolet Spectrometer (EMUS) for the EMM Mission
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Holsclaw, Gregory M., Deighan, Justin, Almatroushi, Hessa, Chaffin, Mike, Correira, John, Evans, J. Scott, Fillingim, Matthew, Hoskins, Alan, Jain, Sonal K., Lillis, Robert, Lootah, Fatma Hussain, McPhate, Jason B., Siegmund, Oswald H. W., Soufli, Regina, and Tyagi, Kush
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- 2021
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6. EMM EMUS Observations of Hot Oxygen Corona at Mars: Radial Distribution and Temporal Variability.
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Chirakkil, Krishnaprasad, Deighan, Justin, Chaffin, Michael S., Jain, Sonal K., Lillis, Robert J., Raghuram, Susarla, Holsclaw, Greg, Brain, David A., Thiemann, Ed, Chamberlin, Phil, Fillingim, Matthew O., Evans, J. Scott, England, Scott, AlMatroushi, Hessa, AlMazmi, Hoor, Eparvier, Frank, Gacesa, Marko, El‐Kork, Nayla, and Curry, Shannon M.
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ROTATION of the Sun ,MARS (Planet) ,SOLAR cycle ,SOLAR oscillations ,SOLAR corona ,ATMOSPHERIC oxygen ,ULTRAVIOLET spectrometers ,OXYGEN - Abstract
We present the first observations of the dayside coronal oxygen emission in far ultraviolet (FUV) measured by the Emirates Mars Ultraviolet Spectrometer (EMUS) onboard the Emirates Mars Mission (EMM). The high sensitivity of EMUS is providing an opportunity to observe the tenuous oxygen corona in FUV, which is otherwise difficult to observe. Oxygen resonance fluorescence emission at 130.4 nm provides a measurement of the upper atmospheric and exospheric oxygen. More than 500 oxygen corona profiles are constructed using the long–exposure time cross–exospheric mode (OS4) of EMUS observations. These profiles range from ∼200 km altitude up to several Mars radii (>6 RM) across all seasons and for two Mars years. Our analysis shows that OI 130.4 nm is highly correlated with solar irradiance (solar photoionizing and 130.4 nm illuminating irradiances) as well as changes in the Sun–Mars distance. The prominent short term periodicity in oxygen corona brightness is consistent with the solar rotation period (quasi–27–day). A comparison between the perihelion seasons of Mars Year (MY) 36 and MY 37 shows interannual variability with enhanced emission intensities during MY 37, due to the rise of Solar Cycle 25. These observations show a highly variable oxygen corona, which has significant implications on constraining the photochemical escape of atomic oxygen from Mars. Plain Language Summary: The highly sensitive Emirates Mars Ultraviolet Spectrometer (EMUS) onboard Emirates Mars Mission (EMM) is capable of observing ultraviolet emissions emanating from Mars. Oxygen in the Martian exosphere is hard to see because it's tenuous. In this study, the analysis of long exposure time EMUS optical observations show that the hot oxygen corona on Mars has a short term variability due to solar rotation. Hot oxygen corona also shows a long–term variability that depends on the Sun–Mars distance and the solar cycle progression. When comparing data from two Martian years, it is noticed that the oxygen corona became brighter when the Sun is more active. Key Points: Brighter O corona is observed during perihelion and dimmer during aphelion, indicating a strong relationship with the Sun‐Mars distanceThe variation in OI 130.4 nm brightness shows a linear correlation with solar EUV irradiance, with a short‐term solar rotation periodicityInterannual variability is observed from MY 36 to MY 37, showing an enhancement in O corona brightness with the rise of Solar Cycle 25 [ABSTRACT FROM AUTHOR]
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- 2024
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7. Thermal Structure of the Martian Upper Mesosphere/Lower Thermosphere From MAVEN/IUVS Stellar Occultations
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Gupta, Sumedha, primary, Yelle, Roger V., additional, Schneider, Nicholas M., additional, Jain, Sonal K., additional, González‐Galindo, Francisco, additional, Verdier, Loic, additional, Braude, Ashwin S., additional, Montmessin, Franck, additional, Mayyasi, Majd, additional, Deighan, Justin, additional, and Curry, Shannon, additional
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- 2022
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8. Laboratory Study of the Cameron Bands and UV Doublet in the Middle Ultraviolet 180–300 nm by Electron Impact upon CO2 with Application to Mars
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Lee, Rena A., primary, Ajello, Joseph M., additional, Malone, Charles P., additional, Evans, J. Scott, additional, Veibell, Victoir, additional, Holsclaw, Gregory M., additional, McClintock, William E., additional, Hoskins, Alan C., additional, Jain, Sonal K., additional, Gérard, Jean-Claude, additional, Aryal, Saurav, additional, and Schneider, Nicholas M., additional
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- 2022
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9. Morphology of Extreme and Far Ultraviolet Martian Airglow Emissions Observed by the EMUS Instrument on Board the Emirates Mars Mission
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Jain, Sonal K., primary, Deighan, Justin, additional, Chaffin, Mike, additional, Holsclaw, Greg, additional, Lillis, Rob, additional, Fillingim, Matt, additional, Evans, J. Scott, additional, Correira, John, additional, AlMatroushi, Hessa, additional, Lootah, Fatma, additional, England, Scott, additional, AlMazmi, Hoor, additional, Thiemann, Ed, additional, Chamberlin, Phil, additional, and Eparvier, Frank, additional
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- 2022
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10. Laboratory Study of the Cameron Bands and UV Doublet in the Middle Ultraviolet 180â€"300 nm by Electron Impact upon CO2 with Application to Mars.
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Lee, Rena A., Ajello, Joseph M., Malone, Charles P., Evans, J. Scott, Veibell, Victoir, Holsclaw, Gregory M., McClintock, William E., Hoskins, Alan C., Jain, Sonal K., GĂ©rard, Jean-Claude, Aryal, Saurav, and Schneider, Nicholas M.
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PHYSICAL constants ,MARS (Planet) ,ELECTRON transport ,ELECTRONS ,AIRGLOW - Abstract
We have observed electron impact fluorescence from CO
2 to excite the Cameron bands (CBs), CO (a3 Î â†' X1 ÎŁ+ ; 180â€"280 nm), the first-negative group (1NG) bands, CO+ (B2 ÎŁ+ â†' X2 ÎŁ+ ; 180â€"320 nm), the fourth-positive group (4PG) bands, CO (A1 Î â†' X1 ÎŁ+ ; 111â€"280 nm), and the UV doublet, CO2 + ( B Ëś 2 ÎŁ u + â†' X Ëś 2 Î g ; 288.3 and 289.6 nm) in the ultraviolet (UV). This wavelength range matches the spectral region of past and present spacecraft equipped to observe UV dayglow and aurora emissions from the thermospheres (100â€"300 km) of Mars and Venus. Our large vacuum system apparatus is able to measure the emission cross sections of the strongest optically forbidden UV transitions found in planetary spectra. Based on our cross-sectional measurements, previous CB emission cross-sectional errors exceed a factor of 3. The UV doublet lifetime is perturbed through B Ëś 2 ÎŁ u + â' A Ëś 2 Î u spinâ€"orbit coupling. Forward modeling codes of the Mars dayglow have not been accurate in the mid-UV due to systematic errors in these two emission cross sections. We furnish absolute emission cross sections for several band systems over electron energies 20â€"100 eV for CO2 . We present a CB lifetime, which together with emission cross sections, furnish a set of fundamental physical constants for electron transport codes such as AURIC (Atmospheric Ultraviolet Radiance Integrated Code). AURIC and Trans-Mars are used in the analysis of UV spectra from the Martian dayglow and aurora. [ABSTRACT FROM AUTHOR]- Published
- 2022
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11. Vertical Propagation of Wave Perturbations in the Middle Atmosphere on Mars by MAVEN/IUVS
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Nakagawa, Hiromu, primary, Terada, Naoki, additional, Jain, Sonal K., additional, Schneider, Nicholas M., additional, Montmessin, Franck, additional, Yelle, Roger V., additional, Jiang, Fayu, additional, Verdier, Loic, additional, England, Scott L., additional, Seki, Kanako, additional, Fujiwara, Hitoshi, additional, Imamura, Takeshi, additional, Yoshida, Nao, additional, Kuroda, Takeshi, additional, Terada, Kaori, additional, Gröller, Hannes, additional, Deighan, Justin, additional, and Jakosky, Bruce M., additional
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- 2020
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12. A Warm Layer in the Nightside Mesosphere of Mars
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Nakagawa, Hiromu, primary, Jain, Sonal K., additional, Schneider, Nicholas M., additional, Montmessin, Franck, additional, Yelle, Roger V., additional, Jiang, Fayu, additional, Verdier, Loic, additional, Kuroda, Takeshi, additional, Yoshida, Nao, additional, Fujiwara, Hitoshi, additional, Imamura, Takeshi, additional, Terada, Naoki, additional, Terada, Kaori, additional, Seki, Kanako, additional, Gröller, Hannes, additional, and Deighan, Justin I., additional
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- 2020
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13. Mars's Twilight Cloud Band: A New Cloud Feature Seen During the Mars Year 34 Global Dust Storm
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Connour, Kyle, primary, Schneider, Nicholas M., additional, Milby, Zachariah, additional, Forget, François, additional, Alhosani, Mohamed, additional, Spiga, Aymeric, additional, Millour, Ehouarn, additional, Lefèvre, Franck, additional, Deighan, Justin, additional, Jain, Sonal K., additional, and Wolff, Michael J., additional
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- 2020
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14. Detection of the Nitric Oxide Dayglow on Mars by MAVEN/IUVS
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Stevens, Michael H., primary, Siskind, David E., additional, Evans, J. Scott, additional, Fox, Jane L., additional, Deighan, Justin, additional, Jain, Sonal K., additional, and Schneider, Nicholas M., additional
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- 2019
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15. Variability of D and H in the Martian Exosphere
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Clarke, John T., Mayyasi, Majd, Bhattacharyya, Dolon, McCord Schneider, Nicholas, Mcclintock, Bill, Deighan, Justin, Stewart, Ian F., Chaufray, Jean-Yves, Chaffin, Michael, Jain, Sonal K., Stiepen, Arnaud, Crismani, Matteo M. J., Holsclaw, Greg, Montmessin, Franck, Jakosky, Bruce Martin, Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), University of Colorado [Boulder], Laboratory for Atmospheric and Space Physics [Boulder] (LASP), HELIOS - 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), PLANETO - LATMOS, and Cardon, Catherine
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[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,[SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[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] ,[PHYS.PHYS.PHYS-AO-PH] Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; The IUVS instrument on MAVEN contains an echelle spectrograph with a novel optical design to enable long-aperture measurements of emission lines in the absence of continuum, intended primarily to measure the H and D Ly α emission lines from the martian upper atmosphere. The main scientific goal of the echelle channel is to measure the H and D Ly α emissions that result from resonant scattering of solar emission and to discover how the H and D densities, temperatures, and escape fluxes vary with location, season, topography, etc. The global D/H ratio of the martian atmosphere is roughly 5 times higher than in the terrestrial atmosphere due to the escape of a large volume of water into space, likely early in the history of Mars. Since H atoms escape faster than D atoms, the D/H ratio increases with time as more water is lost. Earth-based IR observations have indicated large variations in the HDO/H2O ratio in the lower atmosphere from location to location, and possible changes with the atmospheric seasonal cycles [Villanueva et al. 2015]. HST and MEX measurements of the H corona of Mars have shown large (order of magnitude) changes in the H exosphere and escape flux with changing seasons and/or heliospheric distance [Clarke et al. 2014; Chaffin et al. 2014]. A series of observations of D and H with the IUVS echelle channel now show a strong trend in the variation of both emissions, with order of magnitude changes in both species in the upper atmosphere. With the added data expected in Fall 2016, we will be able to determine this trend over a full range of martian solar longitude. These results and a comparison with proposed processes that might lead to the observed changes will be presented.
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- 2016
16. Mars Ozone Mapping with MAVEN IUVS
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Lefèvre, Franck, Montmessin, Franck, Schneider, Nicholas M., Deighan, Justin, Jain, Sonal K., Stewart, Ian, Stiepen, Arnaud, Chaffin, Michael S., Mcclintock, William, Lo, Daniel, Clarke, John, Holsclaw, Greg, Jakosky, Bruce M., STRATO - 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), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], University of Arizona, Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), and Cardon, Catherine
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[SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[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] ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; Ozone (O3) on Mars is a product of the CO2 photolysis by ultraviolet radiation. It is destroyed with a timescale of less than ~1 hour during the day by the H, OH, and HO2 radicals. This tight coupling between O3 and HOx species makes ozone a sensitive tracer of the odd hydrogen chemistry that stabilizes the CO2 atmosphere of Mars, and ozone measurements offer a powerful constraint for photochemical models. Ozone is also expected to be anti-correlated to water vapour, the source of hydrogen radicals HOx. At high latitudes in winter, the absence of H2O prevents the production of HOx and the chemical lifetime of ozone may increase up to several days. In these conditions, the ozone column abundance usually reaches its largest values of the Martian year and ozone turns into a measurable tracer of the polar vortex dynamics.The Imaging Ultraviolet Spectrograph (IUVS) is one of nine science instruments aboard the Mars Atmosphere and Volatile and Evolution (MAVEN) spacecraft. In the apoapse imaging phase, the spacecraft motion carries the IUVS lines-of-sight across the Martian disk while the scan mirror is used to make transverse swaths. This observation mode allows mapping the ozone vertically-integrated column from its signature in the solar ultraviolet flux backscattered by the surface and the atmosphere.This paper will present an overview of the first year of ozone mapping by IUVS. We will describe in particular the last Mars northern winter (2015) when the largest ozone columns have been observed since the beginning of the MAVEN mission. The data will be compared to prior Earth-based observations and to the SPICAM and MARCI ozone datasets. We will also test our quantitative understanding of the Martian ozone by comparing the IUVS observations to our three-dimensional model with photochemistry.
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- 2015
17. Mars Nitric Oxide Nightglow as observed by MAVEN/IUVS
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Stiepen, Arnaud, Stewart, Ian, Jain, Sonal K., Deighan, Justin, Schneider, Nicholas M., Stevens, Michael H., Bougher, Stephen, Evans, Joseph, Chaffin, Michael S., Mcclintock, Bill, Clarke, John, Holsclaw, Greg, Montmessin, Franck, Lefèvre, Franck, Lo, Daniel, Jakosky, Bruce, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Naval Research Laboratory (NRL), Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Computational Physics, Inc., Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), 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), University of Arizona, and Cardon, Catherine
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[SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[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] ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; We report results from a study of nitric oxide nightglow over the northern hemisphere of Mars during winter. We present observations of the nitric oxide δ and γ band emissions between 190 and 270 nm by the Imaging UltraViolet Spectrograph on the MAVEN spacecraft. The emission reveals recombination of N and O atoms dissociated on the dayside of Mars, and is known to trace upper atmosphere hemispheric circulation patterns. We extend previous studies to higher latitudes, finding brighter emissions lower in the atmosphere as predicted from global circulation models. Statistically signicant variability suggests variation of the fluxes of N and O carried from the dayside thermosphere, as well as possible variations of the wind pattern in the nightside thermosphere and mesosphere. We report unexpected variability between the individual components of the nitric oxide band system. We provide statistical characteristics and evaluate possible explanations for this phenomenon.
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- 2015
18. The Hot Oxygen Corona of Mars: Observations by MAVEN IUVS
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Deighan, Justin, Chaffin, Michael, Chaufray, Jean-Yves, Schneider, Nicholas M., Jain, Sonal K., Stiepen, Arnaud, Crismani, Matteo, Clarke, John, Stewart, Ian, Mcclintock, William, Holsclaw, Greg, Montmessin, Franck, Thiemann, Ed, Chamberlin, Phillip, Jakosky, Bruce, Eparvier, Francis, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], HELIOS - 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), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), PLANETO - LATMOS, NASA Goddard Space Flight Center (GSFC), and Cardon, Catherine
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[SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,Physics::Space Physics ,[SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[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] ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; Observation of the Martian hot oxygen corona is an important but difficult measurement in planetary science. These energetic oxygen atoms are thought to be primarily produced by dissociative recombination of O2+ in the planet's ionosphere. While the corona is dominated by gravitationally bound particles, the fraction capable of escaping the planet is expected to be the major pathway for oxygen escape from Mars at the present time. Thus, observing the hot oxygen corona provides valuable insight into the planet’s atmospheric evolution. Up until now, characterization of this population has been elusive due to its extremely tenuous nature. We present here altitude profiles of the hot oxygen corona collected by the MAVEN IUVS instrument as part of its investigation of atmospheric escape from Mars. These measurements confirm the presence of this long anticipated feature of the Martian exosphere, and offer an invaluable way of probing the mechanisms driving escape of atomic oxygen at the present day. Correlation with MAVEN EUVM measurements suggests a relationship between coronal density and solar photoionizing flux, supporting the expectation that dissociative recombination in the ionosphere is the primary source of hot oxygen at Mars. The quality and quantity of the dataset provides valuable constraints for the coronal modeling community, and preliminary comparison of the observed gross structure with a Monte Carlo model is presented.
- Published
- 2015
19. Mars’ ultraviolet dayglow observations by IUVS/MAVEN: Structure and variability of Martian upper atmosphere
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Jain, Sonal K., Stewart, Ian, Schneider, Nicholas M., Deighan, Justin, Stiepen, Arnaud, Evans, Joseph, Stevens, Michael H., Chaffin, Michael S., Crismani, Matteo, Mcclintock, Bill, Clarke, John, Holsclaw, Greg, Lo, Daniel, Lefèvre, Franck, Montmessin, Franck, Thiemann, Ed, Epavier, Francis, Jakosky, Bruce M., Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Computational Physics, Inc., Naval Research Laboratory (NRL), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), University of Arizona, STRATO - 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), and Cardon, Catherine
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[SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[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] ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; Mars has been studied extensively at ultraviolet wavelengths starting from Mariner 6 and 7 (Barth et al. JGR, 1971; Stewart, JGR, 1972), Mariner 9 (Barth et al., Icaurs, 1972; Stewart et al. Icarus, 1972), and more recently by SPICAM aboard Mars Express (Leblanc et al., JGR, 2006). The results from these measurements reveal a large variability in the composition and structure of Martian upper atmosphere. However, due to the lack of simultaneous measurements of energy input in the atmosphere, such as solar electromagnetic and particle flux as well as limitations in the observation geometry and data itself, this variability is still not fully understood.We report a comprehensive study of Mars dayglow observations by the Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) satellite, focusing on upper atmospheric structure and seasonal variability. The dayglow emission spectra show features similar to previous UV measurements at Mars. The IUVS detected a second, low-altitude peak in the emission profile of OI 297.2 nm, confirmation of the prediction that the absorption of solar Lyman alpha emission is an important energy source there. We find a significant drop in thermospheric scale height and temperature between Ls = 218° and Ls = 337 - 352°, attributed primarily to the decrease in solar activity and increase in heliocentric distance. The CO2+ UVD peak intensity is well correlated with simultaneous observations of solar 17 - 22 nm irradiance at Mars by Extreme Ultraviolet Monitor (EUVM) aboard MAVEN. I will present and discuss the variability in Martian UV dayglow, its dependence on solar EUV irradiance, and the importance of IUVS observations in our current understanding of Mars’ thermosphere.
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- 2015
20. Structure and variability of the Martian upper atmosphere: Ultraviolet dayglow observations by MAVEN/IUVS
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Deighan, Justin, Jain, Sonal K., Lo, Daniel Y., Stewart, A. Ian F., Schneider, Nicholas M., Stiepen, Arnaud, Evans, J. Scott, Stevens, Michael H., Yelle, Roger V., England, Scott L., Chaffin, Michael Scott, Crismani, Matteo, Mcclintock, William E., Clarke, John T., Holsclaw, Greg M., Lefèvre, Franck, Montmessin, Franck, Thiemann, Edward M. B., Eparvier, Frank, Jakosky, Bruce M., Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Computational Physics, Inc., Naval Research Laboratory (NRL), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), 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), University of California [Berkeley], and University of California-University of California
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[SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; Mars has been studied extensively at ultraviolet wavelengths starting from Mariner 6 and 7, Mariner 9, and more recently by SPICAM aboard Mars Express. The results from these measurements reveal a large variability in the composition and structure of the Martian upper atmosphere. However, due to the lack of simultaneous measurements of energy input (such as solar electromagnetic and particle flux), and limitations in the observation geometry and data itself, this variability is still not fully understood.We report a comprehensive study of Mars dayglow observations by the Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) satellite, focusing on vertical and global upper atmospheric structure and seasonal variability. The dayglow emission spectra show features similar to previous UV measurements at Mars. IUVS has detected a second, low-altitude peak in the emission profile of OI 297.2 nm, confirming the prediction that the absorption of solar Lyman alpha emission is an important energy source there. We find a significant drop in thermospheric scale height and temperature between Ls = 218° and Ls = 337 - 352°, attributed primarily to the decrease in solar activity and increase in heliocentric distance. The CO2+ UVD peak intensity is well correlated with simultaneous observations of solar 17 - 22 nm irradiance at Mars by Extreme Ultraviolet Monitor (EUVM) aboard MAVEN. Variations of the derived CO2 density also exhibit significant persistent global structure with longitudinal wavenumbers 1, 2 and 3 in a fixed local solar time frame, pointing to non-migrating atmospheric tides driven by diurnal solar heating. We will present and discuss the variability in Martian UV dayglow, its dependence on solar EUV flux, and the importance of IUVS observations in our current understanding of Mars’ thermosphere.
- Published
- 2015
21. New Observations of Molecular Nitrogen by the Imaging Ultraviolet Spectrograph on MAVEN
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Stevens, Michael H., Evans, J. Scott, Schneider, Nicholas M., Stewart, A. Ian F., Deighan, Justin, Jain, Sonal K., Crismani, Matteo M. J., Stiepen, Arnaud, Chaffin, Michael S., Mcclintock, William E., Holsclaw, Greg M., Lefèvre, Franck, Montmessin, Franck, Lo, Daniel Y., Clarke, John T., Bougher, Stephen W., Jakosky, Bruce M., Naval Research Laboratory (NRL), Computational Physics, Inc., Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], 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), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, and Cardon, Catherine
- Subjects
[SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,[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] ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; The Martian ultraviolet dayglow provides information on the basic state of the Martian upper atmosphere. The Imaging Ultraviolet Spectrograph (IUVS) on NASA’s Mars Atmosphere and Volatile Evolution (MAVEN) mission has observed Mars at mid and far-UV wavelengths since its arrival in September 2014. In this work, we describe a linear regression method used to extract components of UV spectra from IUVS limb observations and focus in particular on molecular nitrogen (N2) photoelectron excited emissions. We identify N2 Lyman-Birge-Hopfield (LBH) emissions for the first time at Mars and we also confirm the tentative identification of N2 Vegard-Kaplan (VK) emissions. We compare observed VK and LBH limb radiance profiles to model results between 90 and 210 km. Finally, we compare retrieved N2 density profiles to general circulation (GCM) model results. Contrary to earlier analyses using other satellite data that indicated N2 densities were a factor of three less than predictions, we find that N2 abundances exceed GCM results by about a factor of two at 130 km but are in agreement at 150 km.
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- 2015
22. Two Types of Aurora on Mars as Observed by MAVEN's Imaging UltraViolet Spectrograph
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Schneider, Nicholas M., Deighan, Justin, Jain, Sonal K., Stiepen, Arnaud, Larson, Davin, Mitchell, D. L., Lee, Christina O., Lillis, Robert, Brain, David, Mcclintock, William E., Chaffin, Michael Scott, Crismani, Matteo, Holsclaw, Greg M., Jakosky, Bruce M., Mazelle, Christian, Evans, J. Scott, Stewart, A. Ian F., Stevens, M. H., Clarke, John T., Montmessin, Franck, Lefèvre, Franck, Lo, Daniel, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley] (UC Berkeley), University of California (UC)-University of California (UC), 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), Computational Physics, Inc., Naval Research Laboratory (NRL), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), 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), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, University of California [Berkeley], University of California-University of California, 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
Physics::Space Physics ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,Astrophysics::Earth and Planetary Astrophysics ,Physics::Atmospheric and Oceanic Physics ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; The Imaging UltraViolet Spectrograph (IUVS) on the MAVEN spacecraft has detected two distinct types of auroral emission on Mars. First, we report the discovery of a low altitude, diffuse aurora spanning much of Mars’ northern hemisphere coincident with a solar energetic particle outburst. IUVS observed northerly latitudes during late December 2014, detecting auroral emission in virtually all nightside observations for ~5 days spanning virtually all geographic longitudes. The vertical profile showed emission down to ~70 km altitude (1 microbar), deeper than confirmed at any other planet. The onset and duration of emission coincide with the observed arrival of solar energetic particles up to 200 keV precipitating directly and deeply into the atmosphere. Preliminary modeling of the precipitation, energy deposition and spectral line emission yields good matches to the observations. These observations represent a new class of planetary auroras produced in the Martian middle atmosphere. Given minimal magnetic fields over most of the planet, Mars is likely to exhibit aurora more globally than Earth.Second, we confirm the existence of small patches of discrete aurora near crustal magnetic fields in Mars' southern hemisphere, as observed previously by SPICAM on Mars Express (Bertaux et al., Nature, 435, 790-794 (2005)). IUVS observed southern latitudes in July and August 2015, detecting discrete auroral emission in ~1% of suitable observations. Limb scans resolved both vertically and along-slit indicate this type of auroral emission was patchy on the scale of ~40 km, and located at higher altitudes ~140 km. The higher altitudes imply a lower energy of precipitating particles. The mix of spectral emissions also differed signficiantly from the diffuse aurora, indicating different excitation and quenching processes.We will discuss the observed properties of the aurora and associated charged particle precipitation, as well as the broader implications of this high-energy deposition into Mars' atmopshere.
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- 2015
23. The structure and variability of Mars dayside thermosphere from MAVEN NGIMS and IUVS measurements: Seasonal and solar activity trends in scale heights and temperatures
- Author
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Bougher, Stephen W., primary, Roeten, Kali J., additional, Olsen, Kirk, additional, Mahaffy, Paul R., additional, Benna, Mehdi, additional, Elrod, Meredith, additional, Jain, Sonal K., additional, Schneider, Nicholas M., additional, Deighan, Justin, additional, Thiemann, Ed, additional, Eparvier, Francis G., additional, Stiepen, Arnaud, additional, and Jakosky, Bruce M., additional
- Published
- 2017
- Full Text
- View/download PDF
24. H Escape in 3D: MAVEN IUVS observations of the Mars corona
- Author
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Chaffin, Michael S., Chaufray, Jean-Yves, Deighan, Justin, Schneider, Nicholas M., Mcclintock, William, Stewart, Ian, Thiemann, Ed, Clarke, John, Holsclaw, Greg, Jain, Sonal K., Crismani, Matteo, Stiepen, Arnaud, Montmessin, Franck, Eparvier, Francis, Chamberlin, Phillip, Jakosky, Bruce M., Cardon, Catherine, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], HELIOS - 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), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), PLANETO - LATMOS, and NASA Goddard Space Flight Center (GSFC)
- Subjects
[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,[SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] - Abstract
International audience; Mars has lost a significant fraction of its initial water inventory to space, as evidenced by surface morphology and an enrichment of the heavy isotope deuterium relative to hydrogen. This loss continues today via thermal Jeans escape of neutral hydrogen from the extended H corona. The Mars Atmosphere and Volatile EvolutioN mission's Imaging Ultraviolet Spectrometer IUVS constrains this escape with high cadence, spatially resolved measurements of the corona in scattered sunlight in the Lyman alpha line of neutral H at 121.6 nm. These measurements indicate spatial variability in the corona never before recognized, with potential effects on reconstructing the escape history of water and on retrieved escape rates from previous spatially unresolved observations. I will present our current progress in retrieving escape rates and density distributions from the IUVS observations, including the degree to which observations of the H corona can constrain the thermospheric general circulation at Mars.
- Published
- 2015
25. Retrieval of CO2 and N2 in the Martian thermosphere using dayglow observations by IUVS on MAVEN
- Author
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Evans, J. Scott, Stevens, Michael H., Lumpe, Jerry D., Schneider, Nick M., Stewart, A. Ian F., Deighan, Justin, Jain, Sonal K., Chaffin, Michael S., Crismani, Matteo, Stiepen, Arnaud, Mcclintock, William E., Holsclaw, Greg M., Lefèvre, Franck, Lo, Daniel Y., Clarke, John T., Eparvier, F. G., Thiemann, E. M. B., Chamberlin, Phillip C., Bougher, S. W., Bell, Jared M., Jakosky, Bruce M., Computational Physics, Inc., Naval Research Laboratory (NRL), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], 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), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), NASA Goddard Space Flight Center (GSFC), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, and National Institute of Aerospace [Hampton] (NIA)
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thermosphere ,dayglow ,composition ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,limb scan ,retrieval - Abstract
International audience; We present direct number density retrievals of carbon dioxide (CO2) and molecular nitrogen (N2) for the upper atmosphere of Mars using limb scan observations during October and November 2014 by the Imaging Ultraviolet Spectrograph on board NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. We use retrieved CO2 densities to derive temperature variability between 170 and 220 km. Analysis of the data shows (1) low-mid latitude northern hemisphere CO2 densities at 170 km vary by a factor of about 2.5, (2) on average, the N2/CO2 increases from 0.042 ± 0.017 at 130 km to 0.12 ± 0.06 at 200 km, and (3) the mean upper atmospheric temperature is 324 ± 22 K for local times near 14:00.
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- 2015
26. Non-Migrating Tides in the Martian Atmosphere as Observed by MAVEN IUVS
- Author
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Lo, Daniel Y., Yelle, Roger V., Schneider, Nicholas M., Jain, Sonal K., Stewart, A. Ian F., England, Scott L., Deighan, Justin I., Stiepen, Arnaud, Evans, J. Scott, Stevens, Michael H., Chaffin, Michael S., Crismani, Matteo M. J., Mcclintock, William E., Clarke, John T., Holsclaw, Gregory M., Lefèvre, Franck, Jakosky, Bruce M., Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Naval Research Laboratory (NRL), Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)
- Subjects
[PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] ,upper atmosphere ,[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph] ,Mars ,MAVEN/IUVS ,atmospheric tides ,CO2 density - Abstract
International audience; Using the Mars Atmospheric and Volatile EvolutioN mission (MAVEN) Imaging Ultraviolet Spectrograph (IUVS), we found periodic longitudinal variations in CO2 density in the Martian atmosphere. The variations exhibit significant structure with longitudinal wave numbers 1, 2, and 3 in an effectively constant local solar time frame, and we attribute this structure to nonmigrating tides. The wave-2 component is dominated by the diurnal eastward moving DE1 tide at the equator and the semidiurnal stationary S0 tide at the midlatitudes. Wave-3 is dominated by the diurnal eastward moving DE2 tide, with possibly the semidiurnal eastward moving SE1 tide causing an amplitude increase at the midlatitudes. Structure in the wave-1 component can be explained by the semidiurnal westward moving SW1 tide.
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- 2015
27. Study of the Martian cold oxygen corona from the O I 130.4 nm by IUVS/MAVEN
- Author
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Chaufray, Jean-Yves, Deighan, Justin, Chaffin, Michael S., Schneider, Nicholas M., Mcclintock, Bill, Stewart, Ian, Jain, Sonal K., Crismani, Matteo, Stiepen, Arnaud, Holsclaw, Greg, Clarke, John, Montmessin, Franck, Eparvier, Francis, Thiemann, Ed, Chamberlin, Phillip, Jakosky, Bruce M., Cardon, Catherine, HELIOS - 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), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Center for Space Physics [Boston] (CSP), Boston University [Boston] (BU), PLANETO - LATMOS, and NASA Goddard Space Flight Center (GSFC)
- Subjects
[SDU.ASTR.IM] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] ,[SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,Physics::Space Physics ,[SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,[SDU.ASTR.SR] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR] ,[SDU.ASTR.EP] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP] ,Astrophysics::Earth and Planetary Astrophysics ,[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM] - Abstract
International audience; The observations of the O I 130.4 nm resonant line performed by the Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile Evolution Mission (MAVEN) are presented. This emission line is observed during the different orbit phases of MAVEN : disk observations at apoapsis, limb scans at periapsis and coronal scans during the outbound orbit leg. The atomic oxygen density which is an important parameter to understand the heating, composition, dynamics of the Martian upper atmosphere and the temperature at 200 km are retrieved from an automatic inversion algorithm. A set of observations performed by IUVS during the first months of the mission are analyzed to study the variabiity of the atomic oxygen in the Martian upper atmosphere. The derived oxygen density and the temperature at the exobase are in the predicted range (107 - 108 cm-3; 200 – 300K) by the current thermospheric models of Mars. The derived parameters are very sensitive to the absolute calibration of the instrument which is the main source of uncertainty on the results presented.
- Published
- 2015
28. Comparison of the Martian thermospheric density and temperature from IUVS/MAVEN data and general circulation modeling
- Author
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Medvedev, Alexander S., primary, Nakagawa, Hiromu, additional, Mockel, Chris, additional, Yiğit, Erdal, additional, Kuroda, Takeshi, additional, Hartogh, Paul, additional, Terada, Kaori, additional, Terada, Naoki, additional, Seki, Kanako, additional, Schneider, Nicholas M., additional, Jain, Sonal K., additional, Evans, J. Scott, additional, Deighan, Justin I., additional, McClintock, William E., additional, Lo, Daniel, additional, and Jakosky, Bruce M., additional
- Published
- 2016
- Full Text
- View/download PDF
29. Nonmigrating tides in the Martian atmosphere as observed by MAVEN IUVS
- Author
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Lo, Daniel Y., primary, Yelle, Roger V., additional, Schneider, Nicholas M., additional, Jain, Sonal K., additional, Stewart, A. Ian F., additional, England, Scott L., additional, Deighan, Justin I., additional, Stiepen, Arnaud, additional, Evans, J. Scott, additional, Stevens, Michael H., additional, Chaffin, Michael S., additional, Crismani, Matteo M. J., additional, McClintock, William E., additional, Clarke, John T., additional, Holsclaw, Gregory M., additional, Lefèvre, Franck, additional, and Jakosky, Bruce M., additional
- Published
- 2015
- Full Text
- View/download PDF
30. Ultraviolet observations of the hydrogen coma of comet C/2013 A1 (Siding Spring) by MAVEN/IUVS
- Author
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Crismani, Matteo M. J., primary, Schneider, Nicholas M., additional, Deighan, Justin I., additional, Stewart, A. Ian F., additional, Combi, Michael, additional, Chaffin, Michael S., additional, Fougere, Nicolas, additional, Jain, Sonal K., additional, Stiepen, Arnaud, additional, Yelle, Roger V., additional, McClintock, William E., additional, Clarke, John T., additional, Holsclaw, Gregory M., additional, Montmessin, Frank, additional, and Jakosky, Bruce M., additional
- Published
- 2015
- Full Text
- View/download PDF
Catalog
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