Search

Your search keyword '"Lewis, Stephen R."' showing total 548 results
Start Over Author "Lewis, Stephen R." Search Limiters Academic (Peer-Reviewed) Journals
548 results on '"Lewis, Stephen R."'

1. Atmospheric retrievals suggest the presence of a secondary atmosphere and possible sulfur species on L 98-59 d from JWST NIRSpec G395H transmission spectroscopy

Author

Banerjee, Agnibha, Barstow, Joanna K., Gressier, Amélie, Espinoza, Néstor, Sing, David K., Allen, Natalie H., Birkmann, Stephan M., Challener, Ryan C., Crouzet, Nicolas, Haswell, Carole A., Lewis, Nikole K., Lewis, Stephen R., and Yang, Jingxuan

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

L 98-59 d is a Super-Earth planet orbiting an M-type star. We performed retrievals on the transmission spectrum of L 98-59 d obtained using NIRSpec G395H during a single transit, from JWST Cycle 1 GTO 1224. The wavelength range of this spectrum allows us to detect the presence of several atmospheric species. We found that the spectrum is consistent with a high mean molecular weight atmosphere. The atmospheric spectrum indicates the possible presence of the sulfur-bearing species H$_2$S and SO$_2$, which could hint at active volcanism on this planet if verified by future observations. We also tested for signs of stellar contamination in the spectrum, and found signs of unocculted faculae on the star. The tentative signs of an atmosphere on L 98-59 d presented in this work from just one transit bodes well for possible molecular detections in the future, particularly as it is one of the best targets among small exoplanets for atmospheric characterization using JWST., Comment: Accepted for publication to ApJL

Published
2024
Full Text
View/download PDF

3. Effect of Centrifugal Force on Transmission Spectroscopy of Exoplanet Atmospheres

Author

Banerjee, Agnibha, Barstow, Joanna K., Haswell, Carole A., and Lewis, Stephen R.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

Transmission spectroscopy is one of the most successful methods of learning about exoplanet atmospheres. The process of retrievals using transmission spectroscopy consists of creating numerous forward models and comparing them to observations to solve the inverse problem of constraining the atmospheric properties of exoplanets. We explore the impact of one simplifying assumption commonly employed by forward models of transiting exoplanets: namely that the planet can be treated as an isolated, non-rotating spherical body. The centrifugal acceleration due to a planet's rotation opposes the gravitational pull on a planet's atmosphere and increases its scale height. Conventional forward models used for retrievals generally do not include this effect. We find that atmospheric retrievals produce significantly different results for close-in planets with low gravity when this assumption is removed, e.g., differences between true and retrieved values of gas abundances greater than 1$\sigma$ for a simulated planet analogous to WASP-19 b. We recommend that the correction to the atmospheric scale height due to this effect be taken into account for the analysis of high precision transmission spectra of exoplanets in the future, most immediately JWST Cycle 1 targets WASP-19 b and WASP-121 b., Comment: 5 pages, 4 figures, accepted for publication in MNRAS Letters

Published
2023
Full Text
View/download PDF

8. Investigating the Semiannual Oscillation on Mars using data assimilation

Author

Ruan, Tao, Lewis, Neil T., Lewis, Stephen R., Montabone, Luca, and Read, Peter L.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Atmospheric and Oceanic Physics
Abstract

A Martian semiannual oscillation (SAO), similar to that in the Earth's tropical stratosphere, is evident in the Mars Analysis Correction Data Assimilation reanalysis dataset (MACDA) version 1.0, not only in the tropics, but also extending to higher latitudes. Unlike on Earth, the Martian SAO is found not always to reverse its zonal wind direction, but only manifests itself as a deceleration of the dominant wind at certain pressure levels and latitudes. Singular System Analysis (SSA) is further applied on the zonal-mean zonal wind in different latitude bands to reveal the characteristics of SAO phenomena at different latitudes. The second pair of principal components (PCs) is usually dominated by a SAO signal, though the SAO signal can be strong enough to manifest itself also in the first pair of PCs. An analysis of terms in the Transformed Eulerian Mean equation (TEM) is applied in the tropics to further elucidate the forcing processes driving the tendency of the zonal-mean zonal wind. The zonal-mean meridional advection is found to correlate strongly with the observed oscillations of zonal-mean zonal wind, and supplies the majority of the westward (retrograde) forcing in the SAO cycle. The forcing due to various non-zonal waves supplies forcing to the zonal-mean zonal wind that is nearly the opposite of the forcing due to meridional advection above ~3 Pa altitude, but it also partly supports the SAO between 40 Pa and 3 Pa. Some distinctive features occurring during the period of the Mars year (MY) 25 global-scale dust storm (GDS) are also notable in our diagnostic results with substantially stronger values of eastward and westward momentum in the second half of MY 25 and stronger forcing due to vertical advection, transient waves and thermal tides., Comment: Accepted for publication in Icarus. 20 pages, 5 figures

Published
2019
Full Text
View/download PDF

9. Martian Dust

Author

Newman, Claire E., primary, Bertrand, Tanguy, additional, Fenton, Lori K., additional, Guzewich, Scott D., additional, Jackson, Brian, additional, Lewis, Stephen R., additional, Mischna, Michael A., additional, Montabone, Luca, additional, and Wellington, Danika F., additional

Published
2022
Full Text
View/download PDF

12. The high-resolution map of Oxia Planum, Mars; the landing site of the ExoMars Rosalind Franklin rover mission

Author

European Space Agency, Centre National D'Etudes Spatiales (France), U.S. Geological Survey, Centre National de la Recherche Scientifique (France), University of Bern, European Commission, UK Space Agency, Istituto Nazionale di Astrofisica, Ministerio de Economía y Competitividad (España), University of Arizona, National Aeronautics and Space Administration (US), Ministry of Education and Science of the Russian Federation, Agencia Estatal de Investigación (España), Science and Technology Facilities Council (UK), Agenzia Spaziale Italiana, Martin-Torres, Javier [0000-0001-6479-2236], Zorzano, Maria-Paz [0000-0002-4492-9650], Fawdon, Peter, Orgel, Csilla, Adeli, Solmaz, Balme, Matt, Calef, Fred J., Davis, Joel M., Frigeri, Alessandro, Grindrod, Peter, Hauber, Ernst, Deit, Laetitia Le, Loizeau, Damien, Nass, Andrea, Quantin-Nataf, Cathy, Sefton-Nash, Elliot, Thomas, Nick, Torres, Ines, Vago, Jorge L., Volat, Matthieu, De Witte, Sander, Altieri, Francesca, Apuzzo, Andrea, Aramendia, Julene, Arana, Gorka, Singh Bahia, Rickbir, Banham, Steven G., Barnes, Robert, Barrett, Alexander M., Benedix, Wolf-Stefan, Bhardwaj, Anshuman, Boazman, Sarah Jane, Bontognali, Tomaso R. R., Bridges, John, Bultel, Benjamin, Ciarletti, Valérie, De Sanctis, Maria Cristina, Dickeson, Zach, Favaro, Elena A., Ferrari, Marco, Foucher, Frédéric, Goetz, Walter, Haldemann, Albert F. C., Harrington, Elise, Kapatza, Angeliki, Koschny, Detlef, Krzesinska, Agata M., Le Gall, Alice, Lewis, Stephen R., Lim, Tanya, Madariaga, Juan Manuel, Man, Benjamin James, Mandon, Lucia, Mangold, Nicolas, Martin-Torres, Javier, McNeil, Joseph D., Molina-Jurado, Antonio, Moral, Andoni G., Motaghian, Sara, Nikiforov, Sergei, Oudart, Nicolas, Pacifici, Andrea, Parkes Bowen, Adam, Plettemeier, Dirk, Poulakis, Pantelis, Putri, Alfiah Rizky Diana, Ruesch, Ottaviano, Sam, Lydia, Schröder, Christian, Statz, Christoph, Thomas, Rebecca, Tirsch, Daniela, Toth, Zsuzsanna, Turner, Stuart, Voelker, Martin, Werner, Stephanie C., Westall, Frances, Whiteside, Barry J., Williams, Adam, Williams, Rebecca M. E., Wright, Jack, Zorzano, Maria-Paz, European Space Agency, Centre National D'Etudes Spatiales (France), U.S. Geological Survey, Centre National de la Recherche Scientifique (France), University of Bern, European Commission, UK Space Agency, Istituto Nazionale di Astrofisica, Ministerio de Economía y Competitividad (España), University of Arizona, National Aeronautics and Space Administration (US), Ministry of Education and Science of the Russian Federation, Agencia Estatal de Investigación (España), Science and Technology Facilities Council (UK), Agenzia Spaziale Italiana, Martin-Torres, Javier [0000-0001-6479-2236], Zorzano, Maria-Paz [0000-0002-4492-9650], Fawdon, Peter, Orgel, Csilla, Adeli, Solmaz, Balme, Matt, Calef, Fred J., Davis, Joel M., Frigeri, Alessandro, Grindrod, Peter, Hauber, Ernst, Deit, Laetitia Le, Loizeau, Damien, Nass, Andrea, Quantin-Nataf, Cathy, Sefton-Nash, Elliot, Thomas, Nick, Torres, Ines, Vago, Jorge L., Volat, Matthieu, De Witte, Sander, Altieri, Francesca, Apuzzo, Andrea, Aramendia, Julene, Arana, Gorka, Singh Bahia, Rickbir, Banham, Steven G., Barnes, Robert, Barrett, Alexander M., Benedix, Wolf-Stefan, Bhardwaj, Anshuman, Boazman, Sarah Jane, Bontognali, Tomaso R. R., Bridges, John, Bultel, Benjamin, Ciarletti, Valérie, De Sanctis, Maria Cristina, Dickeson, Zach, Favaro, Elena A., Ferrari, Marco, Foucher, Frédéric, Goetz, Walter, Haldemann, Albert F. C., Harrington, Elise, Kapatza, Angeliki, Koschny, Detlef, Krzesinska, Agata M., Le Gall, Alice, Lewis, Stephen R., Lim, Tanya, Madariaga, Juan Manuel, Man, Benjamin James, Mandon, Lucia, Mangold, Nicolas, Martin-Torres, Javier, McNeil, Joseph D., Molina-Jurado, Antonio, Moral, Andoni G., Motaghian, Sara, Nikiforov, Sergei, Oudart, Nicolas, Pacifici, Andrea, Parkes Bowen, Adam, Plettemeier, Dirk, Poulakis, Pantelis, Putri, Alfiah Rizky Diana, Ruesch, Ottaviano, Sam, Lydia, Schröder, Christian, Statz, Christoph, Thomas, Rebecca, Tirsch, Daniela, Toth, Zsuzsanna, Turner, Stuart, Voelker, Martin, Werner, Stephanie C., Westall, Frances, Whiteside, Barry J., Williams, Adam, Williams, Rebecca M. E., Wright, Jack, and Zorzano, Maria-Paz

Abstract

This 1:30,000 scale geological map describes Oxia Planum, Mars, the landing site for the ExoMars Rosalind Franklin rover mission. The map represents our current understanding of bedrock units and their relationships prior to Rosalind Franklin’s exploration of this location. The map details 15 bedrock units organised into 6 groups and 7 textural and surficial units. The bedrock units were identified using visible and near-infrared remote sensing datasets. The objectives of this map are (i) to identify where the most astrobiologically relevant rocks are likely to be found, (ii) to show where hypotheses about their geological context (within Oxia Planum and in the wider geological history of Mars) can be tested, (iii) to inform both the long-term (hundreds of metres to ∼1 km) and the short-term (tens of metres) activity planning for rover exploration, and (iv) to allow the samples analysed by the rover to be interpreted within their regional geological context.

Published
2024

13. How, when and where current mass flows in Martian gullies are driven by CO2 sublimation

Author

Biogeomorphology of Rivers and Estuaries, Landdegradatie en aardobservatie, Roelofs, Lonneke, Conway, Susan J., de Haas, Tjalling, Dundas, Colin, Lewis, Stephen R., McElwaine, Jim, Pasquon, Kelly, Raack, Jan, Sylvest, Matthew, Patel, Manish R., Biogeomorphology of Rivers and Estuaries, Landdegradatie en aardobservatie, Roelofs, Lonneke, Conway, Susan J., de Haas, Tjalling, Dundas, Colin, Lewis, Stephen R., McElwaine, Jim, Pasquon, Kelly, Raack, Jan, Sylvest, Matthew, and Patel, Manish R.

Published
2024

17. The atmosphere of Mars as observed by InSight

Author

Banfield, Don, Spiga, Aymeric, Newman, Claire, Forget, François, Lemmon, Mark, Lorenz, Ralph, Murdoch, Naomi, Viudez-Moreiras, Daniel, Pla-Garcia, Jorge, Garcia, Raphaël F., Lognonné, Philippe, Karatekin, Özgür, Perrin, Clément, Martire, Léo, Teanby, Nicholas, Hove, Bart Van, Maki, Justin N., Kenda, Balthasar, Mueller, Nils T., Rodriguez, Sébastien, Kawamura, Taichi, McClean, John B., Stott, Alexander E., Charalambous, Constantinos, Millour, Ehouarn, Johnson, Catherine L., Mittelholz, Anna, Määttänen, Anni, Lewis, Stephen R., Clinton, John, Stähler, Simon C., Ceylan, Savas, Giardini, Domenico, Warren, Tristram, Pike, William T., Daubar, Ingrid, Golombek, Matthew, Rolland, Lucie, Widmer-Schnidrig, Rudolf, Mimoun, David, Beucler, Éric, Jacob, Alice, Lucas, Antoine, Baker, Mariah, Ansan, Véronique, Hurst, Kenneth, Mora-Sotomayor, Luis, Navarro, Sara, Torres, Josefina, Lepinette, Alain, Molina, Antonio, Marin-Jimenez, Mercedes, Gomez-Elvira, Javier, Peinado, Veronica, Rodriguez-Manfredi, Jose-Antonio, Carcich, Brian T., Sackett, Stephen, Russell, Christopher T., Spohn, Tilman, Smrekar, Suzanne E., and Banerdt, W. Bruce

Published
2020
Full Text
View/download PDF

27. Eskers associated with buried glaciers in Mars' mid latitudes: recent advances and future directions

Author

Butcher, Frances E.G., Arnold, Neil S., Balme, Matthew R., Conway, Susan J., Clark, Christopher D., Gallagher, Colman, Hagermann, Axel, Lewis, Stephen R., Rutledge, Alicia M., Storrar, Robert D., Woodley, Savana Z., Butcher, Frances E.G., Arnold, Neil S., Balme, Matthew R., Conway, Susan J., Clark, Christopher D., Gallagher, Colman, Hagermann, Axel, Lewis, Stephen R., Rutledge, Alicia M., Storrar, Robert D., and Woodley, Savana Z.

Abstract

Until recently, the influence of basal liquid water on the evolution of buried glaciers in Mars' mid latitudes was assumed to be negligible because the latter stages of Mars' Amazonian period (3 Ga to present) have long been thought to have been similarly cold and dry to today. Recent identifications of several landforms interpreted as eskers associated with these young (100s Ma) glaciers calls this assumption into doubt. They indicate basal melting (at least locally and transiently) of their parent glaciers. Although rare, they demonstrate a more complex mid-to-late Amazonian environment than was previously understood. Here, we discuss several open questions posed by the existence of glacier-linked eskers on Mars, including on their global-scale abundance and distribution, the drivers and dynamics of melting and drainage, and the fate of meltwater upon reaching the ice margin. Such questions provide rich opportunities for collaboration between the Mars and Earth cryosphere research communities., Funder: French Space Agency CNES; STFC (ST/V50693X/1); NASA (80NSSC21K0908); UK Space Agency (ST/R001405/1, ST/T002913/1, ST/V005332/1, ST/W002744/1, ST/W002949/1)

Published
2023
Full Text
View/download PDF

30. List of Contributors

Author

Aye, K.-Michael, primary, Baioni, Davide, additional, Bishop, Mark A., additional, Conway, Susan J., additional, Dixon, John C., additional, Dohm, James M., additional, Gallagher, Colman J., additional, Gulick, Virginia C., additional, Hargitai, Henrik I., additional, Harrison, Tanya N., additional, Hauber, Ernst, additional, Hiesinger, Harald, additional, Johnsson, Andreas, additional, Lewis, Stephen R., additional, Mischna, Michael A., additional, Osinski, Gordon R., additional, Portyankina, Ganna, additional, Reiss, Dennis, additional, Schmidt, Frédéric, additional, Soare, Richard J., additional, Stillman, David E., additional, and Williams, Jean-Pierre, additional

Published
2018
Full Text
View/download PDF

32. ExoMars Atmospheric Mars Entry and Landing Investigations and Analysis (AMELIA)

Author

Ferri, Francesca, Karatekin, Özgür, Lewis, Stephen R., Forget, François, Aboudan, Alessio, Colombatti, Giacomo, Bettanini, Carlo, Debei, Stefano, Van Hove, Bart, Dehant, Veronique, Harri, Ari-Matti, Leese, Mark, Mäkinen, Teemu, Millour, Ehouarn, Muller-Wodarg, Ingo, Ori, Gian Gabriele, Pacifici, Andrea, Paris, Sebastien, Patel, Manish, Schoenenberger, Mark, Herath, Jeffrey, Siili, Tero, Spiga, Aymeric, Tokano, Tetsuya, Towner, Martin, Withers, Paul, Asmar, Sami, and Plettemeier, Dirk

Published
2019
Full Text
View/download PDF

33. Eskers associated with buried glaciers in Mars' mid latitudes: recent advances and future directions.

Author

Butcher, Frances E. G., Arnold, Neil S., Balme, Matthew R., Conway, Susan J., Clark, Christopher D., Gallagher, Colman, Hagermann, Axel, Lewis, Stephen R., Rutledge, Alicia M., Storrar, Robert D., and Woodley, Savana Z.

Subjects
GLACIERS, MELTWATER, MARS (Planet), SCIENTIFIC community, LATITUDE, LANDFORMS, CRYOSPHERE
Abstract

Until recently, the influence of basal liquid water on the evolution of buried glaciers in Mars' mid latitudes was assumed to be negligible because the latter stages of Mars' Amazonian period (3 Ga to present) have long been thought to have been similarly cold and dry to today. Recent identifications of several landforms interpreted as eskers associated with these young (100s Ma) glaciers calls this assumption into doubt. They indicate basal melting (at least locally and transiently) of their parent glaciers. Although rare, they demonstrate a more complex mid-to-late Amazonian environment than was previously understood. Here, we discuss several open questions posed by the existence of glacier-linked eskers on Mars, including on their global-scale abundance and distribution, the drivers and dynamics of melting and drainage, and the fate of meltwater upon reaching the ice margin. Such questions provide rich opportunities for collaboration between the Mars and Earth cryosphere research communities. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

36. Models of Venus Atmosphere

Author

Lebonnois, Sebastien, Lee, Christopher, Yamamoto, Masaru, Dawson, Jonathan, Lewis, Stephen R., Mendonca, Joao, Read, Peter, Parish, Helen F., Schubert, Gerald, Bengtsson, Lennart, Grinspoon, David, Limaye, Sanjay S., Schmidt, Hauke, Svedhem, Håkan, Titov, Dimitri V., Bengtsson, Lennart, editor, Bonnet, Roger-Maurice, editor, Grinspoon, David, editor, Koumoutsaris, Symeon, editor, Lebonnois, Sebastien, editor, and Titov, Dmitri, editor

Published
2013
Full Text
View/download PDF

37. Modeling Efforts

Author

Lewis, Stephen R., Dawson, Jonathan, Lebonnois, Sebastien, Yamamoto, Masaru, Bengtsson, Lennart, editor, Bonnet, Roger-Maurice, editor, Grinspoon, David, editor, Koumoutsaris, Symeon, editor, Lebonnois, Sebastien, editor, and Titov, Dmitri, editor

Published
2013
Full Text
View/download PDF

38. Eskers associated with buried glaciers in Mars' mid latitudes: recent advances and future directions

Author

Butcher, Frances E. G., primary, Arnold, Neil S., additional, Balme, Matthew R., additional, Conway, Susan J., additional, Clark, Christopher D., additional, Gallagher, Colman, additional, Hagermann, Axel, additional, Lewis, Stephen R., additional, Rutledge, Alicia M., additional, Storrar, Robert D., additional, and Woodley, Savana Z., additional

Published
2022
Full Text
View/download PDF

43. The Martian Planetary Boundary Layer

Author

Read, Peter L., primary, Galperin, Boris, additional, Larsen, Søren E., additional, Lewis, Stephen R., additional, Määttänen, Anni, additional, Petrosyan, Arakel, additional, Rennó, Nilton, additional, Savijärvi, Hannu, additional, Siili, Tero, additional, Spiga, Aymeric, additional, Toigo, Anthony, additional, and Vázquez, Luis, additional

Published
2017
Full Text
View/download PDF

44. Dust Devil Sediment Transport: From Lab to Field to Global Impact

Author

Klose, Martina, primary, Jemmett-Smith, Bradley C., additional, Kahanpää, Henrik, additional, Kahre, Melinda, additional, Knippertz, Peter, additional, Lemmon, Mark T., additional, Lewis, Stephen R., additional, Lorenz, Ralph D., additional, Neakrase, Lynn D. V., additional, Newman, Claire, additional, Patel, Manish R., additional, Reiss, Dennis, additional, Spiga, Aymeric, additional, and Whelley, Patrick L., additional

Published
2017
Full Text
View/download PDF

47. Mach and Froude Numbers on Mars

Author

Nasr, Camella-Rosa C., primary, Bradley, Mary E., additional, Lewis, Stephen R., additional, Hollingsworth, Jeffery L., additional, and Dowling, Timothy E., additional

Published
2022
Full Text
View/download PDF

48. Pre- and Post-entry, Descent and Landing Assessment of the Martian Atmosphere for the Mars 2020 Rover

Author

Mischna, Michael A., primary, Villar, Gregory, additional, Kass, David M., additional, Dutta, Soumyo, additional, Rafkin, Scot, additional, Tyler, Daniel, additional, Barnes, Jeffrey, additional, Cantor, Bruce, additional, Lewis, Stephen R., additional, Hinson, David, additional, Pla-García, Jorge, additional, Kleinböhl, Armin, additional, and Karlgaard, Chris, additional

Published
2022
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results