HR: 0800h
AN: SM21B-0377    [Abstracts]
TI: Coordinated Study on Flux Transfer Events Using the Data Observed by TC-1 and Cluster Near Dayside of Magnetopause
AU: * Liu, S
EM: lsl@ustc.edu.cn
AF: University of Science and Technology of China, No. 1, Jinzhai Road, Hefei, 230026 China
AU: Yao, L
SM21B-0377 AF: University of Science and Technology of China, No. 1, Jinzhai Road, Hefei, 230026 China
AU: Jin, S
SM21B-0377 AF: University of Science and Technology of China, No. 1, Jinzhai Road, Hefei, 230026 China
AU: Liu, Z
SM21B-0377 AF: Center for Space Science and Applied Research of the Chinese Academy of Science, No. 1, Nanertiao, ZhongGuancun, Beijing, 100080 China
AU: Shi, J
SM21B-0377 AF: Center for Space Science and Applied Research of the Chinese Academy of Science, No. 1, Nanertiao, ZhongGuancun, Beijing, 100080 China
AB: Flux transfer event (FTE) is a magnetic tube-like construction resulted from patchy and transient reconnection between interplanetary magnetic field (IMF) and magnetospheric field at dayside magnetopause. This paper analyses the magnetic data observed by the first Double Star spacecraft (TC-1) and Cluster II during February to April 2004 when they crossed dayside magnetopause many times at the same time in different latitudes, TC-1 near by the equator and Cluster II close to the cusp region, and 20 FTEs had been detected. Researching the structure of IMF when these FTEs were observed by spacecraft, we found following results: (1) when IMF southward component Bz is dominate, 75 percent of FTEs was detected by TC-1, and 25 percent by Cluster; (2) when IMF By component is dominate, only 17 percent of FTEs was observed by TC-1, and 83 percent by Cluster; (3) when the magnitude of IMF By and Bz southward component were about equal, the number of FTEs detected by TC-1 and Cluster is roughly the same. Above mentioned facts imply that the magnetic reconnection occurred mainly at the low latitude (near the equator) when IMF southward component Bz is dominate and By is smaller, and the magnetic reconnection may occur at the cusp region frequently when IMF By is dominate. And so the magnetic reconnection can occur not only at the cusp region but also at the low latitude when IMF By and southward component Bz both are striking, at this time the coupling between solar wind and magnetosphere was stronger. In addition two FTEs observed by TC-1 at 03:07 UT on 25th February has also been detected by Cluster near the cusp after about 500s. By means of DeHoffmann-Teller Analysis (HTA) we got the speed of this FTE, the transit time from TC-1 to Cluster can derive from this speed. The result shows that the delay in magnetic records of TC-1 and Cluster is about the same with transit time. In addition to the IMF |By/Bz|=0.19, this imply IMF Bz is dominate in that time. These signified that this two FTEs by Cluster at 03:17 UT on 25th February may be born at low latitude, and then moved to the cusp region. In view of above-mentioned the FTEs observed by Cluster, part of them were born in the locality and the other may be born at low latitude then moved to the cusp region. Taking this account the occurrence of magnetic reconnection is quite difficult near cusp region when IMF By component is very small.
DE: 2700 MAGNETOSPHERIC PHYSICS (6939)
DE: 2723 Magnetic reconnection (7526, 7835)
DE: 2724 Magnetopause and boundary layers
SC: SPA-Magnetospheric Physics [SM]
MN: Fall Meeting 2005