Published in

American Geophysical Union, Geophysical Research Letters, 24(41), p. 8713-8721

DOI: 10.1002/2014gl062400

Links

Tools

Export citation

Search in Google Scholar

Increases in plasma sheet temperature with solar wind driving during substorm growth phases: Growth Phase PS Temperature

Journal article published in 2014 by C. Forsyth ORCID, C. E. J. Watt ORCID, I. J. Rae, A. N. Fazakerley, N. M. E. Kalmoni, M. P. Freeman, P. D. Boakes, R. Nakamura, I. Dandouras, L. M. Kistler, C. M. Jackman ORCID, J. C. Coxon ORCID, C. M. Carr
This paper is made freely available by the publisher.
This paper is made freely available by the publisher.

Full text: Download

Green circle
Preprint: archiving allowed
Upload
Green circle
Postprint: archiving allowed
Upload
Orange circle
Published version: archiving restricted
Upload
Policy details
Data provided by SHERPA/RoMEO

Abstract

During substorm growth phases, magnetic reconnection at the magnetopause extracts ∼1015 J from the solar wind which is then stored in the magnetotail lobes. Plasma sheet pressure increases to balance magnetic flux density increases in the lobes. Here we examine plasma sheet pressure, density, and temperature during substorm growth phases using 9 years of Cluster data (>316,000 data points). We show that plasma sheet pressure and temperature are higher during growth phases with higher solar wind driving, whereas the density is approximately constant. We also show a weak correlation between plasma sheet temperature before onset and the minimum SuperMAG AL (SML) auroral index in the subsequent substorm. We discuss how energization of the plasma sheet before onset may result from thermodynamically adiabatic processes; how hotter plasma sheets may result in magnetotail instabilities, and how this relates to the onset and size of the subsequent substorm expansion phase.