[P-EM10] Dynamics of Magnetosphere and Ionosphere

[PEM10-P06] Ion outflow from lobe reconnection and its relation to shear flow

*Haruto Koike¹, Satoshi Taguchi¹ (1.Department of Geophysics, Graduate School of Science, Kyoto University)

Keywords:magnetopause, lobe reconnection, shear flow

One of the important topics for magnetic reconnection is the role of shear flow which flows parallel to the reconnecting field. Previous simulation studies have suggested that shear flow reduces the reconnection rate and the outflow speed. Further studies need be done from observations to understand the role of shear flow in reconnection deeply. For reconnection at the high-latitude magnetopause during northward IMF, the magnetosheath flow streaming tailward acts as shear flow. In this study, we took the lobe reconnection events observed by the Cluster satellites, and examined relationships of the ion outflow to the magnetosheath tailward flow. The result from the statistical analysis has shown that there is a tendency for the ion outflow to increase as the speed of the magnetosheath flow increases. This indicates that ions are more greatly accelerated through the lobe reconnection as shear flow streams faster. This tendency seems to be inconsistent with the result from the previous simulation studies. We will discuss this discrepancy in terms of additional acceleration by the Hall electric field in the ion diffusion region.