Open AccessNitrogen loss from Titan
Author(s) -
Shematovich V. I.,
Johnson R. E.,
Michael M.,
Luhmann J. G.
Publication year - 2003
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2003je002094
Subject(s) - sputtering , titan (rocket family) , ion , atomic physics , atmosphere of titan , dissociation (chemistry) , nitrogen , ionization , dissociative recombination , materials science , astrobiology , physics , chemistry , nanotechnology , thin film , biochemistry , quantum mechanics , recombination , gene
Dissociation and dissociative ionization of molecular nitrogen by solar UV radiation and by photoelectrons and sputtering by the magnetospheric ions and pickup ions are the main sources of translationally excited (hot) nitrogen atoms and molecules in the upper atmosphere of Titan. As Titan does not posses an intrinsic magnetic field, Saturn's magnetospheric ions can penetrate Titan's exobase and sputter atoms and molecules from it. The sputtering of nitrogen from Titan's upper atmosphere by the corotating nitrogen ions and by photodissociation was addressed earlier [ Lammer and Bauer , 1993; Shematovich et al. , 2001]. Here penetration of slowed and deflected magnetospheric N + and carbon‐containing pickup ions is described using a Monte Carlo model. The interaction of these ions with the atmospheric neutrals leads to the production of fast neutrals that collide with other atmospheric neutrals producing heating and ejection of atoms and molecules. Results from Brecht et al. [2000] are used to estimate the net flux and energy spectra of the magnetospheric and pickup ions onto the exobase. Sputtering is primarily responsible for any ejected molecular nitrogen, and, for the ion fluxes used, we show that the total sputtering contribution is comparable to or larger than the dissociation contribution giving a total loss rate of ∼3.6 × 10 25 nitrogen neutrals per second.