Taylor, M. G. G. T. and Hasegawa, H. and Lavraud, B. and Phan, T. and Escoubet, C. P. and Dunlop, M. W. and Bogdanova, Y. V. and Borg, A. L. and Volwerk, M. and Berchem, J. and Constantinescu, O. D. and Eastwood, J. P. and Masson, A. and Laakso, H. and Soucek, J. and Fazakerley, A. N. and Frey, H. U. and Panov, E. V. and Shen, C. and Shi, J. K. and Sibeck, D. G. and Pu, Z. Y. and Wang, J. and Wild, J. A. (2012) Spatial distribution of rolled up Kelvin-Helmholtz vortices at Earth's dayside and flank magnetopause. Annales Geophysicae, 30 (6). pp. 1025-1035. 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 similar to 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.