Evidence for quasi-stationary reconnection at the dayside magnetopause
Evidence for quasi-stationary reconnection at the dayside magnetopause
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DOI：
10.1029/ja087ia04p02147
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发表时间：
1982-04
影响因子：
--
通讯作者：
J. Gosling;J. Asbridge;S. Bame;W. Feldman;G. Paschmann;N. Sckopke;C. Russell
中科院分区：
文献类型：
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作者：
J. Gosling;J. Asbridge;S. Bame;W. Feldman;G. Paschmann;N. Sckopke;C. Russell
在1979年11月22日至23日的大约5小时内，当ISEE 1和2号卫星在当地时间0900左右接近轨道远地点（大约22.2 R/sub E/）时，发生了几次与地球磁层顶的极不寻常的遭遇。这些遥远的磁层顶交叉对应于太阳下地球磁层顶距离约为20.4 R/sub E/，并与太阳风动压下降到一个值（约1.4 x 10/sup-10/dynes cm/sup-2/），比典型值低约100倍。在这5小时期间，在几颗卫星的每一颗上都观测到了具有磁层顶和边界层的加速等离子体流，其大小和方向与重联理论的预测一致。此外，通过磁层顶层的磁场变化表明，磁层顶的结构的旋转不连续的重联理论所要求的。因此，这些观测结果表明，有时在向阳面磁层顶重联可以是一个准定常过程。在这5小时内，以及此后至少9小时内，地磁活动都非常低。因此，昼侧重联当然不是地磁活动增强的充分条件。
Several highly unusual encounters with the earth's magnetopause occurred during an approx.5-hour period on November 22--23, 1979, when the ISEE 1 and 2 satellites were near orbit apogee (approx.22.2 R/sub E/) at approx.0900 local time. These distant magnetopause crossings corresponded to a subsolar earth-magnetopause distance of approx.20.4 R/sub E/ and were associated with a drop in solar wind dynamic pressure to a value (approx.1.4 x 10/sup -10/ dynes cm/sup -2/)approx.100 times lower than is typical. Accelerated plasma flows whose magnitude and direction were consistent with the predictions of reconnection theory were observed on each of several satellite enecounters with the magnetopause and boundary layer during this 5-hour period. Further, the field variation through the magnetopause layer suggest that the magnetopause had the structure of a rotational discontinuity as required by reconnection theory. These observations thus indicate that on occasion reconnection at the dayside magnetopause can be a quasi-stationary process. Geomagnetic activity during this 5-hour period, and for at least 9 hours thereafter, was extremely low. Thus dayside reconnection is certainly not a sufficient condition for enhanced geomagnetic activity.