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| Titel |
Meridional Variations of Stratospheric Temperatures and Hydrocarbon Abundances in Neptune's Stratosphere |
| VerfasserIn |
Thomas Greathouse, Julianne Moses, Thérèse Encrenaz, Glenn Orton, Heidi Hammel, Matthew Richter, John Lacy |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250035479
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| Zusammenfassung |
| Using TEXES – the Texas Echelon cross Echelle Spectrograph – mounted on the
GEMINI North 8-m telescope in October 2007, we mapped the spatial variation of
H2, CH4, C2H2 and C2H6 thermal infrared emissions on Neptune. We employ the
high spectral and spatial resolution mid-infrared ground-based observations of the
ν4 band of methane and the S(1) line of molecular hydrogen to retrieve detailed
information on Neptune’s stratospheric vertical and meridional thermal structure. We
then use the inferred temperatures to model the emissions of C2H2 and C2H6 in
order to derive stratospheric mixing ratios as a function of pressure and latitude. At
R=λ-Îλ=80,000, these observations provide the highest spectral resolution of any
spatially-resolved thermal-infrared spectra to date. As such, they offer a unique
glimpse into the state of Neptune’s stratosphere in October 2007. The results are
compared with a radiative seasonal model of Neptune to place the observations in some
context.
We also present the first high resolution observations of C2H4 in Neptune’s stratosphere.
The spectra, retrieved in June 2003 using TEXES mounted on the NASA IRTF,
was never published due to the lack of observations capable of first inferring the
temperature of Neptune’s stratosphere. We now present an analysis of the observations
modeled using an average of the inferred temperature profiles retrieved from the 2007
observations.
This work was funded by NASA PAST grant NNX08AW33G and NASA PATM grant
NNX08AL95G. |
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