Empirical determination of solar proton access to the atmosphere: Impact on polar flight paths
Empirical determination of solar proton access to the atmosphere: Impact on polar flight paths
复制标题
太阳质子进入大气的经验确定：对极地飞行路径的影响
DOI：
10.1002/swe.20066
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
J. Green
中科院分区：
文献类型：
--
作者：
J. Neal;C. Rodger;J. Green
太阳表面的暴力驱逐释放出高能的太阳质子，最终影响飞机使用的短波通信。地磁场屏蔽了低海拔的赤道地区，但这些质子可以进入两极上空的大气。太阳质子可以到达的纬度随着地磁指数的变化而变化，例如Kp和DST。在这项研究中，我们使用来自近地轨道的观测来确定太阳质子的大气通道，从而确定最有可能受到影响的飞行路径。分析了多达6颗极轨卫星在15次太阳质子事件期间所进行的观测。由此，我们确定了三个能量通道的16,850个质子刚性截止值。经验拟合用来估计截断依赖于地磁活动的最可能的行为。Kp值的变化导致截止值的变化~3 h。我们给出了简单的公式，根据给定的Kp值或DST值可以确定质子撞击大气的地磁纬度。Kp截止点的变化与现有业务模式中所用的变化相似，尽管我们建议纬度向赤道方向移动~1-2°将提供更高的精度。我们发现，Kp预测模型可以为质子截止值的变化提供额外的警告。因此，可以对未来的截止纬度做出~3 h到7 h的预测，满足航空业建议的最短规划时间。
Violent expulsions on the Sun's surface release high energy solar protons that ultimately affect HF communication used by aircraft. The geomagnetic field screens the low altitude equatorial region, but these protons can access the atmosphere over the poles. The latitudes over which the solar protons can reach vary with geomagnetic indices such as Kp and Dst. In this study we use observations from low Earth orbit to determine the atmospheric access of solar protons and hence the flights paths most likely to be affected. Observations taken by up to six polar orbiting satellites during 15 solar proton events are analyzed. From this we determine 16,850 proton rigidity cutoff estimates across three energy channels. Empirical fits are undertaken to estimate the most likely behavior of the cutoff dependence with geomagnetic activity. The changing Kp value is found to lead the variation in the cutoffs by ~3 h. We provide simple equations by which the geomagnetic latitude at which the protons impact the atmosphere can be determined from a given Kp or Dst value. The variation found in the cutoff with Kp is similar to that used in existing operational models, although we suggest that a ~1–2° equatorward shift in latitude would provide greater accuracy. We find that a Kp predictive model can provide additional warning to the variation in proton cutoffs. Hence, a prediction of the cutoff latitudes can be made ~3 h to as much as 7 h into the future, meeting suggested minimum planning times required by the aviation industry.