Swalwell B, Dalla S, Walsh R W
Jeremiah Horrocks Institute, University of Central Lancashire, Preston, PR1 2HE UK.
Sol Phys. 2017;292(11):173. doi: 10.1007/s11207-017-1196-y. Epub 2017 Nov 10.
Solar energetic particle (SEP) events are known to occur following solar flares and coronal mass ejections (CMEs). However, some high-energy solar events do not result in SEPs being detected at Earth, and it is these types of event which may be termed "false alarms". We define two simple SEP forecasting algorithms based upon the occurrence of a magnetically well-connected CME with a speed in excess of (a "fast" CME) or a well-connected X-class flare and analyse them with respect to historical datasets. We compare the parameters of those solar events which produced an enhancement of protons at Earth (an "SEP event") and the parameters of false alarms. We find that an SEP forecasting algorithm based solely upon the occurrence of a well-connected fast CME produces fewer false alarms (28.8%) than an algorithm which is based solely upon a well-connected X-class flare (50.6%). Both algorithms fail to forecast a relatively high percentage of SEP events (53.2% and 50.6%, respectively). Our analysis of the historical datasets shows that false-alarm X-class flares were either not associated with any CME, or were associated with a CME slower than ; false-alarm fast CMEs tended to be associated with flare classes lower than M3. A better approach to forecasting would be an algorithm which takes as its base the occurrence of both CMEs and flares. We define a new forecasting algorithm which uses a combination of CME and flare parameters, and we show that the false-alarm ratio is similar to that for the algorithm based upon fast CMEs (29.6%), but the percentage of SEP events not forecast is reduced to 32.4%. Lists of the solar events which gave rise to protons and the false alarms have been derived and are made available to aid further study.
The online version of this article (doi:10.1007/s11207-017-1196-y) contains supplementary material, which is available to authorized users.
已知太阳高能粒子（SEP）事件会在太阳耀斑和日冕物质抛射（CME）之后发生。然而，一些高能太阳事件并未导致在地球上检测到SEP，正是这类事件可被称为“误报”。我们基于速度超过（一个“快速”CME）的磁连接良好的CME或连接良好的X级耀斑的出现定义了两种简单的SEP预测算法，并针对历史数据集对它们进行分析。我们比较了那些在地球上产生质子增强的太阳事件（一个“SEP事件”）的参数和误报的参数。我们发现，仅基于连接良好的快速CME出现的SEP预测算法产生的误报（28.8%）比仅基于连接良好的X级耀斑的算法（50.6%）少。两种算法都未能预测到相对较高比例的SEP事件（分别为53.2%和50.6%）。我们对历史数据集的分析表明，误报的X级耀斑要么与任何CME都不相关，要么与速度低于的CME相关；误报的快速CME往往与低于M3级的耀斑相关。更好的预测方法是一种以CME和耀斑的出现为基础的算法。我们定义了一种新的预测算法，它使用了CME和耀斑参数的组合，并且我们表明误报率与基于快速CME的算法相似（29.6%），但未被预测的SEP事件的百分比降低到了32.4%。已得出产生质子的太阳事件和误报的列表，并可供进一步研究使用。
本文的在线版本（doi:10.1007/s11207-017-1196-y）包含补充材料，授权用户可获取。
