eprintid: 1421406
rev_number: 33
eprint_status: archive
userid: 608
dir: disk0/01/42/14/06
datestamp: 2014-03-20 19:54:45
lastmod: 2021-10-04 01:20:16
status_changed: 2014-03-20 19:54:45
type: article
metadata_visibility: show
item_issues_count: 0
creators_name: Yates, JN
creators_name: Achilleos, N
creators_name: Guio, P
title: Response of the Jovian thermosphere to a transient 'pulse' in solar wind pressure
ispublished: pub
divisions: UCL
divisions: B04
divisions: C06
divisions: F60
keywords: Jupiter, Magnetosphere, Thermosphere, Angular momentum, Transient, Time-dependent
note: © 2013 The Authors. Published by Elsevier Ltd. All rights reserved. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and
reproduction in any medium, provided the original author and source are credited.
abstract: The importance of the Jovian thermosphere with regard to magnetosphere–ionosphere coupling is often neglected in magnetospheric physics. We present the first study to investigate the response of the Jovian thermosphere to transient variations in solar wind dynamic pressure, using an azimuthally symmetric global circulation model coupled to a simple magnetosphere and fixed auroral conductivity model. In our simulations, the Jovian magnetosphere encounters a solar wind shock or rarefaction region and is subsequently compressed or expanded. We present the ensuing response of the coupling currents, thermospheric flows, heating and cooling terms, and the aurora to these transient events. Transient compressions cause the reversal, with respect to steady state, of magnetosphere–ionosphere coupling currents and momentum transfer between the thermosphere and magnetosphere. They also cause at least a factor of two increase in the Joule heating rate. Ion drag significantly changes the kinetic energy of the thermospheric neutrals depending on whether the magnetosphere is compressed or expanded. Local temperature variations appear between View the MathML source~−45and175K for the compression scenario and View the MathML source~−20and50K for the expansion case. Extended regions of equatorward flow develop in the wake of compression events – we discuss the implications of this behaviour for global energy transport. Both compressions and expansions lead to a View the MathML source~2000TW increase in the total power dissipated or deposited in the thermosphere. In terms of auroral processes, transient compressions increase main oval UV emission by a factor of ~4.5~4.5 whilst transient expansions increase this main emission by a more modest 37%. Both types of transient event cause shifts in the position of the main oval, of up to 1° latitude.
date: 2014-02
official_url: http://dx.doi.org/10.1016/j.pss.2013.11.009
vfaculties: VMPS
oa_status: green
full_text_type: pub
primo: open
primo_central: open_green
verified: verified_manual
elements_source: WoS-Lite
elements_id: 846164
doi: 10.1016/j.pss.2013.11.009
lyricists_name: Achilleos, Nicholas
lyricists_name: Guio, Patrick
lyricists_id: NACHI54
lyricists_id: PGUIO81
full_text_status: public
publication: PLANETARY AND SPACE SCIENCE
volume: 91
pagerange: 27 - 44
issn: 0032-0633
citation:        Yates, JN;    Achilleos, N;    Guio, P;      (2014)    Response of the Jovian thermosphere to a transient 'pulse' in solar wind pressure.                   PLANETARY AND SPACE SCIENCE , 91    27 - 44.    10.1016/j.pss.2013.11.009 <https://doi.org/10.1016/j.pss.2013.11.009>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/1421406/1/1-s2.0-S0032063313003218-main.pdf