Ionization balance in Titan's nightside ionosphere
2015 (English)In: Icarus (New York, N.Y. 1962), ISSN 0019-1035, E-ISSN 1090-2643, Vol. 248, 539-546 p.Article in journal (Refereed) Published
Based on a multi-instrumental Cassini dataset we make model versus observation comparisons of plasma number densities, n(p) = (n(e)n(1))(1/2) (n(e) and n(1) being the electron number density and total positive ion number density, respectively) and short-lived ion number densities (N+, CH2+, CH3+, CH4+) in the southern hemisphere of Titan's nightside ionosphere over altitudes ranging from 1100 and 1200 km and from 1100 to 1350 km, respectively. The n(p) model assumes photochemical equilibrium, ion-electron pair production driven by magnetospheric electron precipitation and dissociative recombination as the principal plasma neutralization process. The model to derive short-lived-ion number densities assumes photochemical equilibrium for the short-lived ions, primary ion production by electron-impact ionization of N-2 and CH4 and removal of the short-lived ions through reactions with CH4. It is shown that the models reasonably reproduce the observations, both with regards to tip and the number densities of the short-lived ions. This is contrasted by the difficulties in accurately reproducing ion and electron number densities in Titan's sunlit ionosphere. (C) 2014 Elsevier Inc. All rights reserved.
Place, publisher, year, edition, pages
2015. Vol. 248, 539-546 p.
Titan, Ionospheres, Titan, atmosphere
Astronomy, Astrophysics and Cosmology
IdentifiersURN: urn:nbn:se:uu:diva-247497DOI: 10.1016/j.icarus.2014.11.012ISI: 000348411000037OAI: oai:DiVA.org:uu-247497DiVA: diva2:796448