Analysis of plasmaspheric plumes: CLUSTER and IMAGE observations

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Authors
Darrouzet, F.
De Keyser, J.
Décréau, P.M.E.
Gallagher, D.L.
Pierrard, V.
Lemaire, J.F.
Sandel, B.R.
Dandouras, I.
Matsui, H.
Dunlop, M.
Cabrera, J.
Masson, A.
Canu, P.
Trotignon, J.G.
Rauch, J.L.
André, M.
Discipline
Physical sciences
Subject
geometry
observational method
orientation
plasma
plume
velocity
Audience
Scientific
Date
2006Metadata
Show full item recordDescription
Plasmaspheric plumes have been routinely observed by CLUSTER and IMAGE. The CLUSTER mission provides high time resolution four-point measurements of the plasmasphere near perigee. Total electron density profiles have been derived from the electron plasma frequency identified by the WHISPER sounder supplemented, in-between soundings, by relative variations of the spacecraft potential measured by the electric field instrument EFW; ion velocity is also measured onboard these satellites. The EUV imager onboard the IMAGE spacecraft provides global images of the plasmasphere with a spatial resolution of 0.1 RE every 10 min; such images acquired near apogee from high above the pole show the geometry of plasmaspheric plumes, their evolution and motion. We present coordinated observations of three plume events and compare CLUSTER in-situ data with global images of the plasmasphere obtained by IMAGE. In particular, we study the geometry and the orientation of plasmaspheric plumes by using four-point analysis methods. We compare several aspects of plume motion as determined by different methods: (i) inner and outer plume boundary velocity calculated from time delays of this boundary as observed by the wave experiment WHISPER on the four spacecraft, (ii) drift velocity measured by the electron drift instrument EDI onboard CLUSTER and (iii) global velocity determined from successive EUV images. These different techniques consistently indicate that plasmaspheric plumes rotate around the Earth, with their foot fully co-rotating, but with their tip rotating slower and moving farther out.
Citation
Darrouzet, F.; De Keyser, J.; Décréau, P.M.E.; Gallagher, D.L.; Pierrard, V.; Lemaire, J.F.; Sandel, B.R.; Dandouras, I.; Matsui, H.; Dunlop, M.; Cabrera, J.; Masson, A.; Canu, P.; Trotignon, J.G.; Rauch, J.L.; André, M. (2006). Analysis of plasmaspheric plumes: CLUSTER and IMAGE observations. , Annales Geophysicae, Vol. 24, Issue 6, 1737-1758, DOI: 10.5194/angeo-24-1737-2006.Identifiers
scopus: 2-s2.0-33751099816
Type
Article
Peer-Review
Yes
Language
eng