Imperial College London
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Dr Ravindra T. Desai

Faculty of Natural Sciences, Department of Physics

Academic Visitor
 
 
 
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Contact

 

ravindra.desai Website

 
 
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Location

 

Blackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Mihailescu:2020:PSJ/abb1ba,
author = {Mihailescu, AT and Desai, R and Shebanits, O and Haythornthwaite, R and Wellbrock, A and Coates, A and Eastwood, J and Waite, JH},
doi = {PSJ/abb1ba},
journal = {The Planetary Science Journal},
pages = {1--8},
title = {Spatial variations of low mass negative ions in Titan's upper atmosphere},
url = {http://dx.doi.org/10.3847/PSJ/abb1ba},
volume = {1},
year = {2020}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Observations with Cassini’s Electron Spectrometer discovered negative ions in Titan’s ionosphere,at altitudes between 1400 and 950 km.  Within the broad mass distribution extending up to severalt housand amu, two distinct peaks were identified at 25.8-26.0 and 49.0-50.1 amu/q, corresponding to the carbon chain anions CN−and/orC2H−for the first peak and C3N−and/orC4H−for the second peak.  In this study we present the spatial distribution of these low mass negative ions from 28 Titanflybys with favourable observations between 26 October 2004 and 22 May 2012.  We report a trend of  lower  densities  on  the  night  side  and  increased  densities  up  to  twice  as  high  on  the  day  side  at small solar zenith angles.  To further understand this trend, we compare the negative ion densities to the total electron density measured by Cassini’s Langmuir Probe.  We find the low mass negative ion density and the electron density to be proportional to each other on the dayside, but independent of each  other  on  the  night  side.   This  indicates  photochemical  processes  and  is  in  agreement  with  the primary production route for the low mass negative ions being initiated by dissociative reactions with suprathermal electron populations produced by photoionisation.  We also find the ratio ofCN−/C2H−toC3N−/C4H−highly constrained on the day-side, in agreement with this production channel, but notably displays large variations on the nightside.
AU  - Mihailescu,AT
AU  - Desai,R
AU  - Shebanits,O
AU  - Haythornthwaite,R
AU  - Wellbrock,A
AU  - Coates,A
AU  - Eastwood,J
AU  - Waite,JH
DO  - PSJ/abb1ba
EP  - 8
PY  - 2020///
SN  - 2632-3338
SP  - 1
TI  - Spatial variations of low mass negative ions in Titan's upper atmosphere
T2  - The Planetary Science Journal
UR  - http://dx.doi.org/10.3847/PSJ/abb1ba
UR  - https://iopscience.iop.org/article/10.3847/PSJ/abb1ba
UR  - http://hdl.handle.net/10044/1/82349
VL  - 1
ER  -
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