全球μ子探测器网络（GMDN）观测到的2006年12月14日福布什减少的前兆
Precursors of the Forbush Decrease on December 14, 2006 observed with the Global Muon Detector Network (GMDN)
摘要：
我们分析了2006年12月14日全球μ子探测器网络观测到的福布什减少（FD）的前兆。一个强烈的磁暴也记录在这个FD与峰值Kp指数为8+。通过使用“二维地图”的宇宙线强度后，删除的贡献，从周日各向异性，我们成功地提取清晰的签名的前兆。该事件的一个显着特征是，在风暴突然开始（SSC）爆发前一天多首次记录到弱损失锥特征。这表明损失锥前兆出现在太阳日冕物质抛射（CME）爆发后7小时，此时行星际日冕物质抛射（ICME）驱动的行星际激波位于距离太阳0.4天文单位处。我们发现，根据地球的自转，网络中的多个探测器连续观测到了前兆，并证实了前兆在太空中连续存在。这一前兆的较长提前时间（15.6小时）几乎是典型值的两倍，表明IMF在这一事件中比IMF湍流假设的典型功率谱更安静。SSC开始时损失锥各向异性的幅度（-6.45%）是FD大小的两倍以上，表明IP冲击后面的最大强度下降远大于在该事件中地球记录的FD大小。我们还发现，从向阳IMF方向的过剩强度清楚地观察到在10小时前的SSC发病。它表明，这种过剩的强度是一致的测量粒子加速迎面碰撞接近冲击波。这是第一次用μ子探测器详细观测到冲击波反射粒子的前兆。
英文摘要：
We analyze the precursor of a Forbush Decrease (FD) observed with the Global Muon Detector Network on December 14, 2006. An intense geomagnetic storm is also recorded during this FD with the peak Kp index of 8+. By using the "two-dimensional map" of the cosmic ray intensity produced after removing the contribution from the diurnal anisotropy, we succeed in extracting clear signatures of the precursor. A striking feature of this event is that a weak loss-cone signature is first recorded more than a day prior to the Storm Sudden Commencement (SSC) onset. This suggests that the loss-cone precursor appeared only 7 hours after the Coronal Mass Ejection (CME) eruption from the Sun, when the Interplanetary (IP) shock driven by the Interplanetary Coronal Mass Ejection (ICME) located at 0.4 AU from the Sun. We find the precursor being successively observed with multiple detectors in the network according to the Earth's spin and confirmed that the precursor continuously exists in space. The long lead time (15.6 hours) of this precursor which is almost twice the typical value indicates that the IMF was more quiet in this event than a typical power spectrum assumed for the IMF turbulence. The amplitude (-6.45 %) of the loss-cone anisotropy at the SSC onset is more than twice the FD size, indicating that the maximum intensity depression behind the IP shock is much larger than the FD size recorded at the Earth in this event. We also find the excess intensity from the sunward IMF direction clearly observed during ~10 hours preceding the SSC onset. It is shown that this excess intensity is consistent with the measurement of the particles accelerated by the head-on collisions with the approaching shock. This is the first detailed observation of the precursor due to the shock reflected particles with muon detectors.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
