DMSP/F2 electron observations of equatorward auroral boundaries and their relationship to the solar wind velocity and the north‐south component of the interplanetary magnetic field
DMSP/F2 electron observations of equatorward auroral boundaries and their relationship to the solar wind velocity and the north‐south component of the interplanetary magnetic field
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DOI：
10.1029/ja086ia12p09961
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发表时间：
1981-11
影响因子：
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通讯作者：
D. Hardy;W. J. Burke;M. Gussenhoven;N. Heinemann;E. Holeman
中科院分区：
文献类型：
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作者：
D. Hardy;W. J. Burke;M. Gussenhoven;N. Heinemann;E. Holeman
当行星际磁场和太阳风速度V的小时平均值可用时，确定了大约2500个极光电子降水的赤道边界。根据DMSP/F2卫星上的SSJ/3电子探测器在椭圆形早晨0400 - 1100时和椭圆形晚上1500 - 2300时的磁性局部扇区返回的数据确定了赤道边界。边界数据在磁地方时被划分为1小时带。在每个区域内，边界位置作为Bz和Bz²、VBz和VBz²的函数进行了研究。当边界与测量边界前一小时的Bz和VBz的小时平均值相关时，以及分别对Bz≤1nt和Bz bbb1nt的数据点进行线性回归时，获得了显著的结果。对于Bz≤1nt的点，与Bz和VBz的相关性通常斜率在0.8°至1.2°/nT之间，1.5°至2.5°/mV/m之间，相关系数为~ 0.7。截距的纬度在傍晚扇区随当地时间的增加而降低，在早晨扇区随当地时间的减少而降低。在1 nT以上的范围内，与Bz相关的最佳拟合线斜率和VBz变化符号。斜率范围为- 0.1°至- 0.4°/nT和0.21°至1°/mV/m。相关系数通常小于- 0.4。在Bz的两个范围内，边界与Bz²和VBz²的相关性均比Bz和VBz的相关性差。发现Bz≤1nt时斜率和截距与磁地方时的趋势与先前发现的边界与Kp的相关性相似（Gussenhoven et al., 1981）。在这个Bz范围内，Kp和VBz的关系式为Kp= 2.01-0.91 VBz （mV/m）。根据Ejiri等人（1978）的工作，导出了磁层电势与VBz的关系式。结果与磁层半波整流模型的一般特征和极帽电位的测量结果相一致。
Approximately 2500 equatorward boundaries of auroral electron precipitation were determined for times when hourly averages of the interplanetary magnetic field and solar wind velocity V were available. The equatorward boundaries were determined from data returned by the SSJ/3 electron detector on board the DMSP/F2 satellite in magnetic local sectors between 0400 and 1100 hours on the morningside of the oval and between 1500 and 2300 hours on the eveningside of the oval. The boundary data were separated into 1-hour zones in magnetic local time. Within each zone the boundary locations were studied as functions of Bz and Bz², VBz and VBz². Significant results were obtained when the boundaries were correlated with hourly average of Bz and VBz for the hour preceding the one in which the boundary was measured and when the linear regression was performed separately for data points where Bz ≤ 1 nT and Bz > 1 nT. For points where Bz ≤ 1 nT, the correlation with Bz and VBz gave slopes generally between 0.8° and 1.2°/nT and between 1.5° and 2.5°/mV/m, respectively, with correlation coefficients of ∼0.7. The latitudes of the intercepts tend to decrease with increasing local time in the evening sector and with decreasing local time in the morning sector. In the range above 1 nT, the slope of the best fit line for correlation with Bz, and VBz changes sign. Slopes fall in the range −0.1° to −0.4°/nT and 0.21° to 1°/mV/m. Correlation coefficients are typically worse than −0.4. Correlations of the boundary with Bz² and VBz² for both ranges of Bz are uniformly worse than those for Bz and VBz. The trend in slopes and intercepts with magnetic local time for Bz ≤ 1 nT is found to be similar to that previously found for the correlation of the boundaries with Kp (Gussenhoven et al., 1981). In this range of Bz, Kp and VBz are found to be related by the equation Kp=2.01–0.91 VBz (mV/m). From the work of Ejiri et al. (1978) an equation relating the magnetospheric electric potential to VBz is derived. The results are in agreement with the general features of the half-wave rectifier model of the magnetosphere and measurements of polar cap potential.