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Detailed Reference Information |
Wolf, R.A., Kumar, V., Toffoletto, F.R., Erickson, G.M., Savoie, A.M., Chen, C.X. and Lemon, C.L. (2006). Estimating local plasma sheet PV5/3 from single-spacecraft measurements. Journal of Geophysical Research 111: doi: 10.1029/2006JA012010. issn: 0148-0227. |
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The theory of plasma transport in Earth's plasma sheet depends critically on the entropy parameter PV 5/3, where P is particle pressure and V is the volume of a closed flux tube containing one unit of magnetic flux. Theory suggests that earthward moving flow bursts that inject plasma into the inner magnetosphere consist of flux tubes that have PV 5/3 values that are lower than those of neighboring slow-moving flux tubes. However, there is no way to measure flux tube volume from one spacecraft or a small number of spacecraft. We propose a formula for estimating local PV 5/3 from a single spacecraft in the plasma sheet based on a simple two-dimensional analytic model of plasma in force equilibrium, with some parameters set from local measurements at a spacecraft and other parameters set to fit a series of equilibrated Tsyganenko models. To gain an idea of the expected error, the resulting formula is then tested against various relaxed Tsyganenko models, an equilibrium magnetic field/plasma model with a depleted channel and also a thin-filament MHD calculation. The formula is used to estimate the entropy parameter of flux tubes injected in two substorms, using spacecraft measurements near X = -10 RE in the central plasma sheet. |
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Abstract |
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Keywords
Magnetospheric Physics, Magnetospheric configuration and dynamics, Magnetospheric Physics, Magnetotail, Magnetospheric Physics, Plasma sheet, Magnetospheric Physics, Substorms |
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Publisher
American Geophysical Union 2000 Florida Avenue N.W. Washington, D.C. 20009-1277 USA 1-202-462-6900 1-202-328-0566 service@agu.org |
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