Imperial College London
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Professor Jonathan P. Eastwood

Faculty of Natural Sciences, Department of Physics

Professor of Space Physics
 
 
 
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Contact

 

jonathan.eastwood Website

 
 
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Assistant

 

Mr Luke Kratzmann +44 (0)20 7594 7770

 
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Location

 

Huxley BuildingSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{AkhavanTafti:2019:10.1029/2018ja026311,
author = {AkhavanTafti, M and Slavin, JA and Eastwood, JP and Cassak, PA and Gershman, DJ},
doi = {10.1029/2018ja026311},
journal = {Journal of Geophysical Research: Space Physics},
pages = {5376--5395},
title = {MMS multipoint analysis of FTE evolution: physical characteristics and dynamics},
url = {http://dx.doi.org/10.1029/2018ja026311},
volume = {124},
year = {2019}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - Previous studies have indicated that flux transfer events (FTEs) grow as they convect away from the reconnection site along the magnetopause. This increase in FTE diameter may occur via adiabatic expansion in response to decreasing external pressure away from the subsolar region or due to a continuous supply of magnetic flux and plasma to the FTEs' outer layers by magnetic reconnection. Here we investigate an ensemble of 55 FTEs at the subsolar magnetopause using Magnetospheric Multiscale (MMS) multipoint measurements. The FTEs are initially modeled as quasiforcefree flux ropes in order to infer their geometry and the spacecraft trajectory relative to their central axis. The MMS observations reveal a radiallyinward net force at the outer layers of FTEs which can accelerate plasmas and fields toward the FTE's core region. Inside the FTEs, near the central axis, plasma density is found to decrease as the axial net force increases. It is interpreted that the axial net force accelerates plasmas along the axis in the region of compressing field lines. Statistical analysis of the MMS observations of the 55 FTEs indicates that plasma pressure, Pth, decreases with increasing FTE diameter, λ, as Pth,obsv ∝ λ−0.24. Assuming that all 55 FTEs started out with similar diameters, this rate of plasma pressure decrease with increasing FTE diameter is at least an order of magnitude slower than the theoretical rate for adiabatic expansion (i.e., Pth,adiab. ∝ λ−3.3), suggesting the presence of efficient plasma heating mechanisms, such as magnetic reconnection, to facilitate FTE growth.
AU  - AkhavanTafti,M
AU  - Slavin,JA
AU  - Eastwood,JP
AU  - Cassak,PA
AU  - Gershman,DJ
DO  - 10.1029/2018ja026311
EP  - 5395
PY  - 2019///
SN  - 2169-9380
SP  - 5376
TI  - MMS multipoint analysis of FTE evolution: physical characteristics and dynamics
T2  - Journal of Geophysical Research: Space Physics
UR  - http://dx.doi.org/10.1029/2018ja026311
UR  - https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2018JA026311
UR  - http://hdl.handle.net/10044/1/72604
VL  - 124
ER  -
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