Mapping Titan's HCN in the far infra-red: Implications for photochemistry

N.A. Teanby; P.G.J. Irwin; R. De Kok; C.A. Nixon

doi:10.1039/c001690j

Mapping Titan's HCN in the far infra-red: Implications for photochemistry

N.A. Teanby, P.G.J. Irwin, R. De Kok, C.A. Nixon

Research output: Contribution to journal › Article › Academic › peer-review

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Abstract

Observations of Titan's far infra-red spectra by the Cassini orbiter's Composite InfraRed Spectrometer have been used to determine the latitude distribution of HCN at 1 mbar by fitting the HCN and CO rotational lines in the 18-60 cm^-1 (160-550 μm) spectral range. Results confirm the north polar HCN enrichment previously observed using mid-IR data and support the conclusion that Titan's nitrile species are significantly more enriched than hydrocarbons species with similar predicted photochemical lifetimes. This suggests Titan's photochemical cycle includes an additional sink for nitrogen bearing species. The abundance of CO was also determined, and had a mean value of 55 ± 6 ppm at 20 mbar. However, it was not possible to reliably determine the CO latitude variation due to unconstrained temperatures in the north polar lower stratosphere.

Original language	English
Pages (from-to)	51-64
Number of pages	14
Journal	Faraday Discussions
Volume	147
DOIs	https://doi.org/10.1039/c001690j
Publication status	Published - 2010
Externally published	Yes

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title = "Mapping Titan's HCN in the far infra-red: Implications for photochemistry",

abstract = "Observations of Titan's far infra-red spectra by the Cassini orbiter's Composite InfraRed Spectrometer have been used to determine the latitude distribution of HCN at 1 mbar by fitting the HCN and CO rotational lines in the 18-60 cm-1 (160-550 μm) spectral range. Results confirm the north polar HCN enrichment previously observed using mid-IR data and support the conclusion that Titan's nitrile species are significantly more enriched than hydrocarbons species with similar predicted photochemical lifetimes. This suggests Titan's photochemical cycle includes an additional sink for nitrogen bearing species. The abundance of CO was also determined, and had a mean value of 55 ± 6 ppm at 20 mbar. However, it was not possible to reliably determine the CO latitude variation due to unconstrained temperatures in the north polar lower stratosphere.",

author = "N.A. Teanby and P.G.J. Irwin and {De Kok}, R. and C.A. Nixon",

year = "2010",

doi = "10.1039/c001690j",

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journal = "Faraday Discussions",

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T1 - Mapping Titan's HCN in the far infra-red: Implications for photochemistry

AU - Teanby, N.A.

AU - Irwin, P.G.J.

AU - De Kok, R.

AU - Nixon, C.A.

PY - 2010

Y1 - 2010

N2 - Observations of Titan's far infra-red spectra by the Cassini orbiter's Composite InfraRed Spectrometer have been used to determine the latitude distribution of HCN at 1 mbar by fitting the HCN and CO rotational lines in the 18-60 cm-1 (160-550 μm) spectral range. Results confirm the north polar HCN enrichment previously observed using mid-IR data and support the conclusion that Titan's nitrile species are significantly more enriched than hydrocarbons species with similar predicted photochemical lifetimes. This suggests Titan's photochemical cycle includes an additional sink for nitrogen bearing species. The abundance of CO was also determined, and had a mean value of 55 ± 6 ppm at 20 mbar. However, it was not possible to reliably determine the CO latitude variation due to unconstrained temperatures in the north polar lower stratosphere.

AB - Observations of Titan's far infra-red spectra by the Cassini orbiter's Composite InfraRed Spectrometer have been used to determine the latitude distribution of HCN at 1 mbar by fitting the HCN and CO rotational lines in the 18-60 cm-1 (160-550 μm) spectral range. Results confirm the north polar HCN enrichment previously observed using mid-IR data and support the conclusion that Titan's nitrile species are significantly more enriched than hydrocarbons species with similar predicted photochemical lifetimes. This suggests Titan's photochemical cycle includes an additional sink for nitrogen bearing species. The abundance of CO was also determined, and had a mean value of 55 ± 6 ppm at 20 mbar. However, it was not possible to reliably determine the CO latitude variation due to unconstrained temperatures in the north polar lower stratosphere.

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DO - 10.1039/c001690j

M3 - Article

AN - SCOPUS:78649510361

SN - 1359-6640

VL - 147

SP - 51

EP - 64

JO - Faraday Discussions

JF - Faraday Discussions

ER -

Mapping Titan's HCN in the far infra-red: Implications for photochemistry

Abstract

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