The storm time central plasma sheet
The storm time central plasma sheet
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风暴时间中央等离子体片
DOI：
10.5194/angeo-20-1737-2002
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发表时间：
2002
影响因子：
1.9
通讯作者：
T. Mukai
中科院分区：
文献类型：
--
作者：
R. Schödel;K. Dierschke;Wolfgang Baumjohann;R. Nakamura;T. Mukai
等离子体片在磁暴期间起着关键作用，因为它是从向阳侧磁层顶侵蚀的大量磁通量必须返回到向阳侧磁层的瓶颈。利用近五年的Geotail数据，我们研究了磁暴期间近尾和中尾中央等离子体片（CPS）在10- 30 RE范围内的平均特性。在风暴主相期间，向地通量输送率大大增强，但向地通量输送率却有明显的减小。因此，由于磁通量不能以足够的速率循环，这导致中心等离子体片的平均双极化。在暴主相期间，CPS离子布居的比熵增加了约2倍，这为非绝热加热过程提供了证据。主相期间的通量输送方向与20 RE以上近地中性线的可能形成一致。
The plasma sheet plays a key role during mag- netic storms because it is the bottleneck through which large amounts of magnetic flux that have been eroded from the dayside magnetopause have to be returned to the dayside magnetosphere. Using about five years of Geotail data we studied the average properties of the near- and midtail central plasma sheet (CPS) in the 10-30RE range during magnetic storms. The earthward flux transport rate is greatly enhanced during the storm main phase, but shows a significant earth- ward decrease. Hence, since the magnetic flux cannot be circulated at a sufficient rate, this leads to an average dipo- larization of the central plasma sheet. An increase of the spe- cific entropy of the CPS ion population by a factor of about two during the storm main phase provides evidence for non- adiabatic heating processes. The direction of flux transport during the main phase is consistent with the possible forma- tion of a near-Earth neutral line beyond 20RE.