Thick escaping magnetospheric ion layer in magnetopause reconnection with MMS observations

T. Nagai , N. Kitamura , H. Hasegawa , I. Shinohara , S. Yokota , Y. Saito , R. Nakamura , B. L. Giles , C. Pollock , T. E. Moore , J. C. Dorelli , D. J. Gershman , W. R. Paterson , L. A. Avanov , M. O. Chandler , V. Coffey , J. A. Sauvaud (1) , B. Lavraud (1) , C. T. Russell , R. J. Strangeway , M. Oka , K. J. Genestreti , J. L. Burch

1 IRAP - Institut de recherche en astrophysique et planétologie

The structure of asymmetric magnetopause reconnection is explored with multiple point and high-time-resolution ion velocity distribution observations from the Magnetospheric Multiscale mission. On 9 September 2015, reconnection took place at the magnetopause, which separated the magnetosheath and the magnetosphere with a density ratio of 25:2. The magnetic field intensity was rather constant, even higher in the asymptotic magnetosheath. The reconnected field line region had a width of approximately 540 km. In this region, streaming and gyrating ions are discriminated. The large extension of the reconnected field line region toward the magnetosheath can be identified where a thick layer of escaping magnetospheric ions was formed. The scale of the magnetosheath side of the reconnected field line region relative to the scale of its magnetospheric side was 4.5:1.

Mots clés: magnetic reconnection; magnetopause

Domaines: Planète et Univers [physics]

T. Nagai, N. Kitamura, H. Hasegawa, I. Shinohara, S. Yokota, et al.. Thick escaping magnetospheric ion layer in magnetopause reconnection with MMS observations. Geophysical Research Letters, 2016, 43, pp.6028-6035. ⟨10.1002/2016GL069085⟩. ⟨insu-03669490⟩