HR: 1340h
AN: SM13B-1218    [Abstracts]
TI: Dayside boundary layer under northward IMF: A Cluster perspective
AU: * Zhang, H
EM: zhang@bu.edu
AF: Center for Space Physics,Boston University, 725 Commonwealth Avenue, Boston, MA 02215
AU: Fritz, T
EM: fritz@bu.edu
AF: Center for Space Physics,Boston University, 725 Commonwealth Avenue, Boston, MA 02215
AU: Zong, Q
EM: zong@bu.edu
AF: Center for Space Physics,Boston University, 725 Commonwealth Avenue, Boston, MA 02215
AU: Daly, P
EM: daly@linmpi.mpg.de
AF: Max-Planck-Institute fuer Aeronomie, D-37191, Katlenburg-Lindau, NS 37191 Germany
AB: It has been proposed that the Low Latitude Boundary Layer (LLBL) was formed by high-latitude reconnection when the IMF is northward. To study the relationship between the low-latitude boundary layer and high-latitude boundary layer under northward IMF condition, we present statistical results based on 3 years of data obtained by Cluster when these spacecraft were in the vicinity of the dayside magnetopause during northward IMF. In total 341 cases of Cluster crossing of Low Latitude Boundary Layer (LLBL) and High Latitude Boundary Layer (HLBL) (according to the definition by Phan et al [1996a,b]) have been analyzed in detail in order to study the relation between the LLBL and the HLBL. The plasma density, temperature, velocity, energetic particle flux and magnetic field geometry change across the magnetopause under northward IMF were analyzed by a superposed epoch analysis. It has been suggested [Zong et al, 2004] that the solar wind plasma density decreases in the magnetospheric boundary region in an exponential mannerwith an e-folding distance of 1000 km during northward IMF in a case study. In this statistical study, we explore further the relation between the distance to magnetopause and the penetration of solar wind plasma inside the magnetopause. Phan, T. D., and G. Paschmann, Low-latitude dayside magnetopause and boundary layer for high magnetic sheath: 1. Structure and motion, J. Geophys. Res.,101, 7801-7815, 1996 Phan, T. D., G. Paschmann, and B. U. O. Sonnerup, Low-latitude dayside magnetopause and boundary layer for high magnetic sheath: 2. Occurrence of magnetic reconnection, J. Geophys. Res.,101, 7817-7828, 1996 Zong, Q.-G., T. A. Fritz, H. Spence, K. Oksavik, Z.-Y. Pu, A. Korth, and P. W. Daly, Energetic particle sounding of the magnetopause: A contribution by Cluster/RAPID, J. Geophys. Res.,109, A04207, 2004
DE: 2716 Energetic particles, precipitating
DE: 2720 Energetic particles, trapped
DE: 2724 Magnetopause, cusp, and boundary layers
DE: 2728 Magnetosheath
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting