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Title: THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS

Abstract

HCN is an important constituent in Titan’s upper atmosphere, serving as the main coolant in the local energy budget. In this study, we derive the HCN abundance at the altitude range of 960–1400 km, combining the Ion-Neutral Mass Spectrometer data acquired during a large number of Cassini flybys with Titan. Typically, the HCN abundance declines modestly with increasing altitude and flattens to a near constant level above 1200 km. The data reveal a tendency for dayside depletion of HCN, which is clearly visible below 1000 km but weakens with increasing altitude. Despite the absence of convincing anti-correlation between HCN volume mixing ratio and neutral temperature, we argue that the variability in HCN abundance makes an important contribution to the large temperature variability observed in Titan’s upper atmosphere.

Authors:
;  [1];  [2];  [3]
  1. National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China)
  2. Groupe de Spectroscopie Moleculaire et Atmospherique, Universite de Reims, Champagne-Ardenne, CNRS UMR F-7331 (France)
  3. Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)
Publication Date:
OSTI Identifier:
22654275
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 826; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; ALTITUDE; CORRELATIONS; ECOSYSTEMS; ENERGY BALANCE; HYDROCYANIC ACID; MASS; MASS SPECTROMETERS; MIXING; MIXING RATIO; PLANETS; SATELLITE ATMOSPHERES; SATELLITES; SATURN PLANET

Citation Formats

Cui, J., Cao, Y.-T., Lavvas, P. P., and Koskinen, T. T. THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS. United States: N. p., 2016. Web. doi:10.3847/2041-8205/826/1/L5.
Cui, J., Cao, Y.-T., Lavvas, P. P., & Koskinen, T. T. THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS. United States. doi:10.3847/2041-8205/826/1/L5.
Cui, J., Cao, Y.-T., Lavvas, P. P., and Koskinen, T. T. Wed . "THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS". United States. doi:10.3847/2041-8205/826/1/L5.
@article{osti_22654275,
title = {THE VARIABILITY OF HCN IN TITAN’S UPPER ATMOSPHERE AS IMPLIED BY THE CASSINI ION-NEUTRAL MASS SPECTROMETER MEASUREMENTS},
author = {Cui, J. and Cao, Y.-T. and Lavvas, P. P. and Koskinen, T. T.},
abstractNote = {HCN is an important constituent in Titan’s upper atmosphere, serving as the main coolant in the local energy budget. In this study, we derive the HCN abundance at the altitude range of 960–1400 km, combining the Ion-Neutral Mass Spectrometer data acquired during a large number of Cassini flybys with Titan. Typically, the HCN abundance declines modestly with increasing altitude and flattens to a near constant level above 1200 km. The data reveal a tendency for dayside depletion of HCN, which is clearly visible below 1000 km but weakens with increasing altitude. Despite the absence of convincing anti-correlation between HCN volume mixing ratio and neutral temperature, we argue that the variability in HCN abundance makes an important contribution to the large temperature variability observed in Titan’s upper atmosphere.},
doi = {10.3847/2041-8205/826/1/L5},
journal = {Astrophysical Journal Letters},
number = 1,
volume = 826,
place = {United States},
year = {Wed Jul 20 00:00:00 EDT 2016},
month = {Wed Jul 20 00:00:00 EDT 2016}
}