Wellbrock, A;
Coates, AJ;
Jones, GH;
Vuitton, V;
Lavvas, P;
Desai, RT;
Waite, JH;
(2019)
Heavy negative ion growth in Titan’s polar winter.
Monthly Notices of the Royal Astronomical Society
10.1093/mnras/stz2655.
(In press).
Preview |
Text
Wellbrock_Heavy negative ion growth in Titan’s polar winter_AAM.pdf - Accepted Version Download (2MB) | Preview |
Abstract
A significant but unexpected result of the Cassini mission was the discovery of heavy organic negative ions in Titan’s ionosphere at altitudes between about 950 km and 1400 km by the CAPS Electron Spectrometer (ELS). The heaviest ions were observed during the T16 flyby with masses over 13,000 u/q. This is significantly higher than the maximum masses observed during other flybys. We study T16 CAPS-ELS observations and examine the evolution of mass spectra at different altitudes. We also study maximum mass trends using a large data set from all available CAPS-ELS observations of the Cassini mission, in order to investigate the conditions necessary to allow negative ions to grow to the highest masses. For the first time, we are able to investigate the relationship between the highest mass particles and seasonal effects. We find that the combination of high latitude and winter conditions, resulting in long-term restricted solar flux, create an environment in which ion growth can reach the highest masses, as observed during T16. Restricting solar flux long-term, and hence photo destruction reactions such as photodetachment, appear to be essential for negative ions to grow beyond 10,000 u/q.
| Type: | Article |
|---|---|
| Title: | Heavy negative ion growth in Titan’s polar winter |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1093/mnras/stz2655 |
| Publisher version: | https://doi.org/10.1093/mnras/stz2655 |
| Language: | English |
| Additional information: | This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10083439 |
Archive Staff Only
 |
View Item |
