中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
Dayside nitrogen and carbon escape on Titan: the role of exothermic chemistry

文献类型:期刊论文

作者Gu, H.1; Cui, J.2,3,4; Lavvas, P. P.5; Niu, D-D1; Wu, X-S3,4; Guo JH(郭建恒)6; He, F.7; Wei, Y.7
刊名ASTRONOMY & ASTROPHYSICS
出版日期2019-12-20
卷号633页码:20
ISSN号0004-6361
关键词planets and satellites atmospheres planets and satellites individual Titan
DOI10.1051/0004-6361/201936826
产权排序第6完成单位
文献子类Article
英文摘要

Context. Atmospheric escape has an appreciable impact on the long-term climate evolution on terrestrial planets. Exothermic chemistry serves as an important mechanism driving atmospheric escape and the role of such a mechanism is of great interest for Titan due to its extremely complicated atmospheric and ionospheric composition. Aims. This study is devoted to a detailed investigation of neutral N and C escape on the dayside of Titan, which is driven by exothermic neutral-neutral, ion-neutral, and dissociative recombination (DR) reactions. It was carried out based on the extensive measurements of Titan's upper atmospheric structure by a number of instruments on board Cassini, along with an improved understanding of the chemical network involved. Methods. A total number of 14 C- and N-containing species are investigated based on 146 exothermic chemical reactions that release hot neutrals with nascent energies above their respective local escape energies. For each species and each chemical channel, the hot neutral production rate profile is calculated, which provides an estimate of the corresponding escape rate when combined with the appropriate escape probability profile obtained from a test particle Monte Carlo model. Results. Our calculations suggest a total N escape rate of 9.0 x 10(23) s(-1) and a total C escape rate of 4.2 x 10(23) s(-1), driven by exothermic chemistry and appropriate for the dayside of Titan. The former is primarily contributed by neutral-neutral reactions, whereas the latter is dominated by ion-neutral reactions; however, contributions from neutral-neutral and DR reactions to the latter cannot be ignored either. Our calculations further reveal that the bulk of N escape is driven by hot N(S-4) production from the collisional quenching of N(D-2) by ambient N-2, while C escape is mainly driven by hot CH3 and CH4 production via a number of important ion-neutral and neutral-neutral reactions. Conclusions. Considered in the context of prior investigations of other known escape mechanisms, we suggest that exothermic chemistry is likely to contribute appreciably to non-thermal C escape on the dayside of Titan, although it plays an insignificant role in N escape.

学科主题天文学 ; 太阳与太阳系 ; 行星物理学
URL标识查看原文
出版地AVE DU HOGGAR, PA COURTABOEUF, BP 112, F-91944 LES ULIS CEDEX A, FRANCE
WOS关键词EVALUATED KINETIC-DATA ; ETHYNYL RADICAL C2H ; TEMPERATURE RATE COEFFICIENTS ; ABSOLUTE CROSS-SECTIONS ; ION MOLECULE CHEMISTRY ; ATOM BRANCHING RATIOS ; DISSOCIATIVE RECOMBINATION ; RATE CONSTANTS ; UPPER-ATMOSPHERE ; GAS-PHASE
资助项目Strategic Priority Research Program of the Chinese Academy of Sciences[XDA17010201] ; National Science Foundation of China (NSFC)[41525015] ; National Science Foundation of China (NSFC)[41774186] ; National Science Foundation of China (NSFC)[41525016]
WOS研究方向Astronomy & Astrophysics
语种英语
出版者EDP SCIENCES S A
WOS记录号WOS:000503792300001
资助机构Strategic Priority Research Program of the Chinese Academy of Sciences[XDA17010201] ; National Science Foundation of China (NSFC)[41525015, 41774186, 41525016]
源URL[http://ir.ynao.ac.cn/handle/114a53/22105]  
专题云南天文台_恒星物理研究组
云南天文台_中国科学院天体结构与演化重点实验室
通讯作者Cui, J.
作者单位1.Space Science Institute, Macau University of Science and Technology, Macau, PR China
2.School of Atmospheric Sciences, Sun Yat-Sen University, Zhuhai, Guangdong, PR China
3.National Astronomical Observatories, Chinese Academy of Sciences, Beijing, PR China
4.Chinese Academy of Sciences Center for Excellence in Comparative Planetology, Hefei, Anhui, PR China
5.Université de Reims Champagne Ardenne, CNRS, GSMA UMR 7331, 51097 Reims, France
6.Yunnan Astronomical Observatory, Chinese Academy of Sciences, Kunming, Yunnan, PR China
7.Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, PR China
推荐引用方式
GB/T 7714
Gu, H.,Cui, J.,Lavvas, P. P.,et al. Dayside nitrogen and carbon escape on Titan: the role of exothermic chemistry[J]. ASTRONOMY & ASTROPHYSICS,2019,633:20.
APA Gu, H..,Cui, J..,Lavvas, P. P..,Niu, D-D.,Wu, X-S.,...&Wei, Y..(2019).Dayside nitrogen and carbon escape on Titan: the role of exothermic chemistry.ASTRONOMY & ASTROPHYSICS,633,20.
MLA Gu, H.,et al."Dayside nitrogen and carbon escape on Titan: the role of exothermic chemistry".ASTRONOMY & ASTROPHYSICS 633(2019):20.

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来源:云南天文台

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