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| Titel |
JIRAM for Juno mission: retrieval capabilities for ammonia and water vapour in the hot spots |
| VerfasserIn |
Davide Grassi, Angioletta Coradini, Alberto Adriani |
| 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 |
250039225
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| Zusammenfassung |
| Jupiter’s atmosphere presents limited regions of relatively thin cloud coverage (so-called ’hot
spots’), that allow thermal radiation by warmer, deeper atmospheric layers to be transmitted
directly to space. Hot spots therefore represent a means for probing physical conditions
(namely chemical composition) below the main aerosol deck. The JIRAM instrument is an IR
spectro-imager included in the payload of forthcoming Juno mission to the Jovian system. Its
coverage of 5 μm CH4 transparency window makes it particularly suitable for the
study of hot-spots. Corresponding retrieval capability for mixing ratios of minor
gases are quantitatively assessed on the basis of Bayesian theory. Data will provide
effective constraints on the mixing ratios of water vapor between 40 and 70 km
below the reference 1 bar pressure level (between 3.5 and 7 bars). Assuming an
a priori correlation length equal to half the scale height, we achieve a minimum
retrieval uncertainty of 0.17 once the mixing ratio is given in terms of log10(α),
being α the mixing ratio (vs. altitude) relative to a given reference profile. The
JIRAM-Juno dataset will further allow determination of the ammonia mixing ratio, with a
minimum relative retrieval uncertainty of 0.32 in the same altitude range, and of the
phosphine mixing ratio, with comparable uncertainty up to the reference altitude. |
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