Details

Autor(en) / Beteiligte

• Jain, S. K.
• Stewart, A. I. F.
• Schneider, N. M.
• Deighan, J.
• Stiepen, A.
• Evans, J. S.
• Stevens, M. H.
• Chaffin, M. S.
• Crismani, M.
• McClintock, W. E.
• Clarke, J. T.
• Holsclaw, G. M.
• Lo, D. Y.
• Lefèvre, F.
• Montmessin, F.
• Thiemann, E. M. B.
• Eparvier, F.
• Jakosky, B. M.

Titel

The structure and variability of Mars upper atmosphere as seen in MAVEN/IUVS dayglow observations

Ist Teil von

• Geophysical research letters, 2015-11, Vol.42 (21), p.9023-9030

Ort / Verlag

Washington: Blackwell Publishing Ltd

Erscheinungsjahr

2015

Link zum Volltext

Quelle

Wiley Online Library - AutoHoldings Journals

Beschreibungen/Notizen

• We report a comprehensive study of Mars dayglow observations focusing on upper atmospheric structure and seasonal variability. We analyzed 744 vertical brightness profiles comprised of ∼109,300 spectra obtained with the Imaging Ultraviolet Spectrograph (IUVS) aboard the Mars Atmosphere and Volatile EvolutioN (MAVEN) satellite. The dayglow emission spectra show features similar to previous UV measurements at Mars. 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. We report the detection of 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. The CO2+ UV doublet peak intensity is well correlated with simultaneous observations of solar 17–22 nm irradiance at Mars. Key Points Significant drop in thermospheric temperature between two Martian seasons Detection of second layer of OI 297.2 nm emission below 100 km Strong correlation between observed mid‐UV dayglow and simultaneously measured EUV flux at Mars