Reconnection Efficiency Determined from Statistical Properties of Magnetosheath Flux

Monday, 15 December 2014
Hui Zhang1, Krishan K Khurana2, Margaret Kivelson2, Suiyan Fu3, Zuyin Pu3, Weixing Wan1, Libo Liu1 and Changbo Zhu1, (1)IGG Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China, (2)University of California Los Angeles, Los Angeles, CA, United States, (3)Peking University, Beijing, China
The magnetospheric magnetic reconnection rate, RMR, is used to describe how fast magnetic reconnection proceeds on the dayside magnetopause. In literature, one of the proxies used for determining the reconnection rate is the plasma velocity in the reconnection inflow region, VIN, or, to be more accurate, the convective electric field parallel to the X line in the inflow region, E = VINBIN. On the magnetopause of the Earth, RMR divided by the rate at which solar wind flux is incident on the cross section of the magnetosphere can represent the input efficiency of the interplanetary magnetic field (IMF) into the Earth's magnetosphere. RMR on the magnetopause, however, is modified by local conditions such as the magnetic fields and plasma densities on both sides of the magnetopause. Thus RMR may vary with position on the magnetopause and the integral of RMR over the whole magnetopause is required to estimate the global efficiency of the input of IMF flux into the magnetosphere. We will present a new approach to establishing reconnection efficiency by comparing solar wind flux to measured magnetosheath flux carried in the flow near the terminator. We have conducted statistics on data collected by Cluster in the Earth's magnetosheath from 2001-2013. The global input efficiency of IMF flux into the magnetosphere is estimated and its relationship to the solar wind and IMF conditions is investigated in this presentation.