학술논문
Spatial Distribution of Rolled up Kelvin-Helmholtz Vortices at Earth's Dayside and Flank Magnetopause
Document Type
Report
Author
Taylor, M. G. G. T; Hasegawa, H; Lavraud, B; Phan, T; Escoubet, C. P; Dunlop, M. W; Bogdanova, Y. V; Borg, A. L; Volwerk, M; Berchem, J; Constantinescu, O. D; Eastwood, J. P; Masson, A; Laakso, H; Soucek, J; Fazakerley, A. N; Frey, H. U; Panov, E. V; Shen, C; Shi, J. K; Sibeck, D. G; Pu, Z. Y; Wang, J; Wild, J. A
Source
Annales Geophysicae. 30(6)
Subject
Language
English
ISSN
0992-7689
Abstract
The Kelvin-Helmholtz Instability (KHI) can drive waves at the magnetopause. These waves can grow to form rolled-up vortices and facilitate transfer of plasma into the magnetosphere. To investigate the persistence and frequency of such waves at the magnetopause we have carried out a survey of all Double Star 1 magnetopause crossings, using a combination of ion and magnetic field measurements. Using criteria originally used in a Geotail study made by Hasegawa et al. (2006) (forthwith referred to as H2006), 17 candidate events were identified from the entire TC-1 mission (covering 623 orbits where the magnetopause was sampled), a majority of which were on the dayside of the terminator. The relationship between density and shear velocity was then investigated, to identify the predicted signature of a rolled up vortex from H2006 and all 17 events exhibited some level of rolled up behavior. The location of the events had a clear dawn-dusk asymmetry, with 12 (71 %) on the post noon, dusk flank suggesting preferential growth in this region.