MAVEN/IUVS Perispse Lyman-Alpha Observations: Variability and Constraints on H and CO2 Abundance

Andrea C. G. Hughes; Michael Chaffin; Edwin J. Mierkiewicz; Jean-Yves Chaufray; Justin Deighan; Nick M. Schneider; Edward Thiemann; John T. Clarke; Majd Mayyasi; Sonal K. Jain; Matteo Michael James Crismani; Arnaud Stiepen; Franck Montmessin; Francis Epavier; Ian F. Stewart; Bill McClintock; Greg Holsclaw; Bruce Martin Jakosky

MAVEN/IUVS Perispse Lyman-Alpha Observations: Variability and Constraints on H and CO2 Abundance

Andrea C. G. Hughes, Michael Chaffin, Edwin J. Mierkiewicz, Jean-Yves Chaufray, Justin Deighan, Nick M. Schneider, Edward Thiemann, John T. Clarke, Majd Mayyasi, Sonal K. Jain, Matteo Michael James Crismani, Arnaud Stiepen, Franck Montmessin, Francis Epavier, Ian F. Stewart, Bill McClintock, Greg Holsclaw, Bruce Martin Jakosky

Physical Sciences

Research output: Contribution to conference › Presentation

Abstract

 The abundance of spectroscopic and geomorphologic evidence demonstrating that liquid water
 once flowed on Mars raises significant questions regarding the history of Martian water and the
 evolution of the atmosphere into the current hyper-arid climate. Using data from the Imaging
 UltraViolet Spectrograph (IUVS) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN)
 spacecraft, we evaluate the hydrogen Lyman-alpha emission (121.6 nm) across multiple Martian
 years and solar zenith angles. We create altitude-intensity profiles of atmospheric hydrogen
 emission using periapse data from all MAVEN orbits to-date. Due to the optically thin emission of
 the UV-doublet scale height of mid-ultraviolet IUVS data, we are able to indirectly probe the
 temperature of the atmosphere. By combining mid-ultraviolet and far-ultraviolet IUVS data, we
 extract temperatures and densities of the upper atmosphere and fit the data using a radiative
 transfer forward model. Below 120 km, the H Lyman-alpha emission is absorbed by CO2,
 providing constraint on CO2 in the lower thermosphere. Fitting the altitude-intensity curves below
 120 km altitude and comparing spatial and temporal variations of the profiles allows us to
 constrain CO2 abundances. The results of this work, in combination with other MAVEN findings,
 will provide better constraints on Martian H and CO2 densities and determining neutral
 temperatures, as well as a more thorough understanding of the evolution of the Martian
 atmosphere through time.
 

Original language	American English
State	Published - Dec 14 2017
Event	American Geophysical Union Fall Meeting - New Orleans, LA Duration: Dec 15 2017 → …

Conference

Conference	American Geophysical Union Fall Meeting
Period	12/15/17 → …

Keywords

Mars
atmosphere
hydrogen emission

Disciplines

Astrophysics and Astronomy

Cite this

Hughes, A. C. G., Chaffin, M., Mierkiewicz, E. J., Chaufray, J.-Y., Deighan, J., Schneider, N. M., Thiemann, E., Clarke, J. T., Mayyasi, M., Jain, S. K., Crismani, M. M. J., Stiepen, A., Montmessin, F., Epavier, F., Stewart, I. F., McClintock, B., Holsclaw, G., & Jakosky, B. M. (2017). MAVEN/IUVS Perispse Lyman-Alpha Observations: Variability and Constraints on H and CO2 Abundance. American Geophysical Union Fall Meeting.

Hughes, ACG, Chaffin, M, Mierkiewicz, EJ, Chaufray, J-Y, Deighan, J, Schneider, NM, Thiemann, E, Clarke, JT, Mayyasi, M, Jain, SK, Crismani, MMJ, Stiepen, A, Montmessin, F, Epavier, F, Stewart, IF, McClintock, B, Holsclaw, G & Jakosky, BM 2017, 'MAVEN/IUVS Perispse Lyman-Alpha Observations: Variability and Constraints on H and CO2 Abundance', American Geophysical Union Fall Meeting, 12/15/17.

@conference{9c74cd9a223e49e2a00141cd2df729ce,

title = "MAVEN/IUVS Perispse Lyman-Alpha Observations: Variability and Constraints on H and CO2 Abundance",

abstract = " The abundance of spectroscopic and geomorphologic evidence demonstrating that liquid water once flowed on Mars raises significant questions regarding the history of Martian water and the evolution of the atmosphere into the current hyper-arid climate. Using data from the Imaging UltraViolet Spectrograph (IUVS) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we evaluate the hydrogen Lyman-alpha emission (121.6 nm) across multiple Martian years and solar zenith angles. We create altitude-intensity profiles of atmospheric hydrogen emission using periapse data from all MAVEN orbits to-date. Due to the optically thin emission of the UV-doublet scale height of mid-ultraviolet IUVS data, we are able to indirectly probe the temperature of the atmosphere. By combining mid-ultraviolet and far-ultraviolet IUVS data, we extract temperatures and densities of the upper atmosphere and fit the data using a radiative transfer forward model. Below 120 km, the H Lyman-alpha emission is absorbed by CO2, providing constraint on CO2 in the lower thermosphere. Fitting the altitude-intensity curves below 120 km altitude and comparing spatial and temporal variations of the profiles allows us to constrain CO2 abundances. The results of this work, in combination with other MAVEN findings, will provide better constraints on Martian H and CO2 densities and determining neutral temperatures, as well as a more thorough understanding of the evolution of the Martian atmosphere through time. ",

keywords = "Mars, atmosphere, hydrogen emission",

author = "Hughes, {Andrea C. G.} and Michael Chaffin and Mierkiewicz, {Edwin J.} and Jean-Yves Chaufray and Justin Deighan and Schneider, {Nick M.} and Edward Thiemann and Clarke, {John T.} and Majd Mayyasi and Jain, {Sonal K.} and Crismani, {Matteo Michael James} and Arnaud Stiepen and Franck Montmessin and Francis Epavier and Stewart, {Ian F.} and Bill McClintock and Greg Holsclaw and Jakosky, {Bruce Martin}",

year = "2017",

month = dec,

day = "14",

language = "American English",

note = "American Geophysical Union Fall Meeting ; Conference date: 15-12-2017",

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TY - CONF

T1 - MAVEN/IUVS Perispse Lyman-Alpha Observations: Variability and Constraints on H and CO2 Abundance

AU - Hughes, Andrea C. G.

AU - Chaffin, Michael

AU - Mierkiewicz, Edwin J.

AU - Chaufray, Jean-Yves

AU - Deighan, Justin

AU - Schneider, Nick M.

AU - Thiemann, Edward

AU - Clarke, John T.

AU - Mayyasi, Majd

AU - Jain, Sonal K.

AU - Crismani, Matteo Michael James

AU - Stiepen, Arnaud

AU - Montmessin, Franck

AU - Epavier, Francis

AU - Stewart, Ian F.

AU - McClintock, Bill

AU - Holsclaw, Greg

AU - Jakosky, Bruce Martin

PY - 2017/12/14

Y1 - 2017/12/14

N2 - The abundance of spectroscopic and geomorphologic evidence demonstrating that liquid water once flowed on Mars raises significant questions regarding the history of Martian water and the evolution of the atmosphere into the current hyper-arid climate. Using data from the Imaging UltraViolet Spectrograph (IUVS) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we evaluate the hydrogen Lyman-alpha emission (121.6 nm) across multiple Martian years and solar zenith angles. We create altitude-intensity profiles of atmospheric hydrogen emission using periapse data from all MAVEN orbits to-date. Due to the optically thin emission of the UV-doublet scale height of mid-ultraviolet IUVS data, we are able to indirectly probe the temperature of the atmosphere. By combining mid-ultraviolet and far-ultraviolet IUVS data, we extract temperatures and densities of the upper atmosphere and fit the data using a radiative transfer forward model. Below 120 km, the H Lyman-alpha emission is absorbed by CO2, providing constraint on CO2 in the lower thermosphere. Fitting the altitude-intensity curves below 120 km altitude and comparing spatial and temporal variations of the profiles allows us to constrain CO2 abundances. The results of this work, in combination with other MAVEN findings, will provide better constraints on Martian H and CO2 densities and determining neutral temperatures, as well as a more thorough understanding of the evolution of the Martian atmosphere through time.

AB - The abundance of spectroscopic and geomorphologic evidence demonstrating that liquid water once flowed on Mars raises significant questions regarding the history of Martian water and the evolution of the atmosphere into the current hyper-arid climate. Using data from the Imaging UltraViolet Spectrograph (IUVS) onboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft, we evaluate the hydrogen Lyman-alpha emission (121.6 nm) across multiple Martian years and solar zenith angles. We create altitude-intensity profiles of atmospheric hydrogen emission using periapse data from all MAVEN orbits to-date. Due to the optically thin emission of the UV-doublet scale height of mid-ultraviolet IUVS data, we are able to indirectly probe the temperature of the atmosphere. By combining mid-ultraviolet and far-ultraviolet IUVS data, we extract temperatures and densities of the upper atmosphere and fit the data using a radiative transfer forward model. Below 120 km, the H Lyman-alpha emission is absorbed by CO2, providing constraint on CO2 in the lower thermosphere. Fitting the altitude-intensity curves below 120 km altitude and comparing spatial and temporal variations of the profiles allows us to constrain CO2 abundances. The results of this work, in combination with other MAVEN findings, will provide better constraints on Martian H and CO2 densities and determining neutral temperatures, as well as a more thorough understanding of the evolution of the Martian atmosphere through time.

KW - Mars

KW - atmosphere

KW - hydrogen emission

M3 - Presentation

T2 - American Geophysical Union Fall Meeting

Y2 - 15 December 2017

ER -