Imperial College London
Alternate

Professor Southwood

Faculty of Natural Sciences, Department of Physics

Senior Research Investigator
 
 
 
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Contact

 

+44 (0)20 7594 7770d.southwood CV

 
 
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Location

 

711AHuxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Radioti:2017:10.1002/2016JA023820,
author = {Radioti, A and Grodent, D and Gerard, JC and Southwood, DJ and Chane, E and Bonfond, B and Pryor, W},
doi = {10.1002/2016JA023820},
journal = {Journal of Geophysical Research: Space Physics},
pages = {6078--6087},
title = {Stagnation of Saturn’s auroral emission at noon},
url = {http://dx.doi.org/10.1002/2016JA023820},
volume = {122},
year = {2017}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Auroral emissions serve as a powerful tool to investigate themagnetospheric processes at Saturn. Solar wind and internally driven processes largely control Saturn’s auroral morphology. The main auroral emission at Saturn is suggested to be connected with the magnetosphere - solar wind interaction, through the flow shear related to rotational dynamics. Dawn auroral enhancements are associated with intense field-aligned currents generated by hot tenuous plasma carried towards the planet in fast moving flux tubes as they return from tail reconnection site to the dayside. In this work we demonstrate, based on Cassini auroral observations, that the main auroral emission at Saturn, as it rotates from midnight to dusk via noon, occasionally stagnates near noon over a couple of hours. In half of the sequences examined, the auroral emission is blocked close to noon, while in three out of four cases, the blockage of the auroral emission is accompanied with signatures of dayside reconnection. We discuss some possible interpretations of the auroral ’blockage’ near noon. According to the first one it could be related to local time variations of the flow shear close to noon. Auroral local time variations are also suggested to be initiated by radial transport process. Alternatively, the auroral blockage at noon could be associated with a plasma circulation theory, according to which tenuously populated closed flux tubes as they return from the nightside to the morning sector experience a blockage in the equatorial plane and they cannot rotate beyond noon.
AU  - Radioti,A
AU  - Grodent,D
AU  - Gerard,JC
AU  - Southwood,DJ
AU  - Chane,E
AU  - Bonfond,B
AU  - Pryor,W
DO  - 10.1002/2016JA023820
EP  - 6087
PY  - 2017///
SN  - 2169-9402
SP  - 6078
TI  - Stagnation of Saturn’s auroral emission at noon
T2  - Journal of Geophysical Research: Space Physics
UR  - http://dx.doi.org/10.1002/2016JA023820
UR  - http://hdl.handle.net/10044/1/48685
VL  - 122
ER  -
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