The extreme solar cosmic ray particle event on 20 January 2005 and its influence on the radiation dose rate at aircraft altitude.
The extreme solar cosmic ray particle event on 20 January 2005 and its influence on the radiation dose rate at aircraft altitude.
复制标题
2005年1月20日极端太阳宇宙线粒子事件及其对飞机高度辐射剂量率的影响.
DOI：
10.1016/j.scitotenv.2007.10.021
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
M. Moser
中科院分区：
文献类型：
--
作者：
R. Bütikofer;E. Flückiger;L. Desorgher;M. Moser
2005年1月，太阳活动周期第23周接近尾声时，太阳非常活跃。2005年1月15日至20日期间，太阳活动区NOAA AR 10720产生了五次强烈的太阳耀斑。与这一主要太阳活动有关，观测到了地面宇宙线强度的几个显着变化。这些耀斑中的第五个(X7.1)产生了高能的太阳宇宙射线，导致地面宇宙线探测器(中子监测器)的计数率大幅增加。在南极中子监测站，计数率增加了几千个百分点。根据全球中子监测网络的记录，我们确定了地球附近太阳粒子通量的特征。在该事件的初始阶段，地球附近的太阳宇宙射线通量具有极大的各向异性。太阳宇宙线的能谱在主衰期和衰变期相当软。我们还研究了不同二次粒子在大气中的通量和飞行高度的辐射剂量。我们的分析表明，在飞行高度近三个数量级的情况下，太阳宇宙射线在南极地区的有效剂量率增加幅度最大，大约在70°S和130°E附近。
In January 2005 toward the end of solar activity cycle 23 the Sun was very active. Between 15 and 20 January 2005, the solar active region NOAA AR 10720 produced five powerful solar flares. In association with this major solar activity several pronounced variations in the ground-level cosmic ray intensity were observed. The fifth of these flares (X7.1) produced energetic solar cosmic rays that caused a giant increase in the count rates of the ground-based cosmic ray detectors (neutron monitors). At southern polar neutron monitor stations the increase of the count rate reached several thousand percent. From the recordings of the worldwide network of neutron monitors, we determined the characteristics of the solar particle flux near Earth. In the initial phase of the event, the solar cosmic ray flux near Earth was extremely anisotropic. The energy spectrum of the solar cosmic rays was fairly soft during the main and the decay phase. We investigated also the flux of different secondary particle species in the atmosphere and the radiation dosage at flight altitude. Our analysis shows a maximum increment of the effective dose rate due to solar cosmic rays in the south polar region around 70°S and 130°E at flight altitude of almost three orders of magnitude.