HR: 1340h
AN: SM13B-1208    [Abstracts]
TI: Formation of the Cold Plasma Sheet in the Near-Earth Magnetotail
AU: * Nishino, M N
EM: nishino@eps.s.u-tokyo.ac.jp
AF: The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
AU: Terasawa, T
AF: The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
AU: Hoshino, M
AF: The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
AU: Fujimoto, M
AF: Tokyo Institude of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550 Japan
AU: Mukai, T
AF: JAXA/ISAS, 3-1-1 Yoshinodai, Sagamihara, 229-8510 Japan
AU: Saito, Y
AF: JAXA/ISAS, 3-1-1 Yoshinodai, Sagamihara, 229-8510 Japan
AB: We study the cold plasma sheet found in the near-earth magneotail is studied using the 9 years' data from the Geotail spacecraft. While it has been widely known that the cold plasma sheet (ion temperature $<$ 1 keV) is formed near the both flanks under the northward IMF condition, the time scale as well as the mechanism of formation of the cold plasma sheet is now under debate. We show that the time lag from the northward turning of the IMF to the emergence of the cold plasma sheet is as short as a few hours on the both flanks. We further report that the cold plasma is found not only on the flanks but also at times deep inside the midnight plasma sheet only a few hours after the northward turning of the IMF. These observations suggest that some prompt transport process other than diffusion occurs, although diffusive processes may work on plasma transport near the flanks. We also show that the cold plasma sheet emerges on the dawnside during the weak IMF Bz periods, which implies dawn-dusk asymmetry in the formation of the cold plasma sheet.
DE: 2724 Magnetopause, cusp, and boundary layers
DE: 2731 Magnetosphere--outer
DE: 2744 Magnetotail
DE: 2748 Magnetotail boundary layers
DE: 2764 Plasma sheet
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting