Imperial College London
Alternate

ProfessorMicheleDougherty

Faculty of Natural Sciences, Department of Physics

Head of Department of Physics, Professor of Space Physics
 
 
 
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Contact

 

+44 (0)20 7594 7770m.dougherty Website

 
 
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Assistant

 

Ms Lida Mnatsakanian +44 (0)20 7594 7503

 
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Location

 

Blackett 900aBlackett LaboratorySouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Russell:2016:10.1002/2015JA022293,
author = {Russell, CT and Wei, HY and Cowee, MM and Neubauer, FM and Dougherty, MK},
doi = {10.1002/2015JA022293},
journal = {Journal of Geophysical Research: Space Physics},
pages = {2095--2103},
title = {Ion cyclotron waves at Titan},
url = {http://dx.doi.org/10.1002/2015JA022293},
volume = {121},
year = {2016}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - During the interaction of Titan's thick atmosphere with the ambient plasma, it was expected that ion cyclotron waves would be generated by the free energy of the highly anisotropic velocity distribution of the freshly ionized atmospheric particles created in the interaction. However, ion cyclotron waves are rarely observed near Titan, due to the long growth times of waves associated with the major ion species from Titan's ionosphere, such as CH4+ and N2+. In the over 100 Titan flybys obtained by Cassini to date, there are only two wave events, for just a few minutes during T63 flyby and for tens of minutes during T98 flyby. These waves occur near the gyrofrequencies of proton and singly ionized molecular hydrogen. They are left-handed, elliptically polarized, and propagate nearly parallel to the field lines. Hybrid simulations are performed to understand the wave growth under various conditions in the Titan environment. The simulations using the plasma and field conditions during T63 show that pickup protons with densities ranging from 0.01 cm−3 to 0.02 cm−3 and singly ionized molecular hydrogens with densities ranging from 0.015 cm−3 to 0.25 cm−3 can drive ion cyclotron waves with amplitudes of ~0.02 nT and of ~0.04 nT within appropriate growth times at Titan, respectively. Since the T98 waves were seen farther upstream than the T63 waves, it is possible that the instability was stronger and grew faster on T98 than T63.
AU  - Russell,CT
AU  - Wei,HY
AU  - Cowee,MM
AU  - Neubauer,FM
AU  - Dougherty,MK
DO  - 10.1002/2015JA022293
EP  - 2103
PY  - 2016///
SN  - 2169-9402
SP  - 2095
TI  - Ion cyclotron waves at Titan
T2  - Journal of Geophysical Research: Space Physics
UR  - http://dx.doi.org/10.1002/2015JA022293
UR  - http://hdl.handle.net/10044/1/38576
VL  - 121
ER  -
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