论文标题
机器学习是一台耀眼的风暴警告机:2017年9月太阳能爆炸风暴的警告机吗?
Machine learning as a flaring storm warning machine: Was a warning machine for the September 2017 solar flaring storm possible?
论文作者
论文摘要
如今,机器学习是耀斑预测和监督技术的首选方法,无论是在传统和深层版本中,在这一太空天气中的预测中都是最常用的预测方法。然而,到目前为止,机器学习无法实现爆发风暴的操作警告系统,而过去十年的科学文献表明,它在预测强烈太阳耀斑中的表现并不是最佳的。 与预测太阳能爆炸风暴有关的主要困难大概是两个。首先,大多数方法都被认为是提供概率预测,而不是向延长的时间范围内连续出现火炬的二进制YES/否指示。其次,耀斑的风暴通常以高能量事件的爆炸为特征,高能量事件的爆炸很少记录在太空任务的数据库中。结果,对监督的方法进行了训练,以非常不平衡的历史场景进行了培训,这使得它们对于预测强烈的耀斑特别无效。 然而,在这项研究中,我们表明,可以使用一种监督的机器学习来发送有关过去十年中最暴力和最出乎意料的爆发事件的及时警告,甚至可以准确地预测整个风暴过程中磁性重新连接的能源预算每日释放的能量预算。此外,我们表明,增强稀疏机器学习和功能排名的组合可以识别能源在预测过程中作为活动区域属性所起的重要作用。
Machine learning is nowadays the methodology of choice for flare forecasting and supervised techniques, in both their traditional and deep versions, are becoming the most frequently used ones for prediction in this area of space weather. Yet, machine learning has not been able so far to realize an operating warning system for flaring storms and the scientific literature of the last decade suggests that its performances in the prediction of intense solar flares are not optimal. The main difficulties related to forecasting solar flaring storms are probably two. First, most methods are conceived to provide probabilistic predictions and not to send binary yes/no indications on the consecutive occurrence of flares along an extended time range. Second, flaring storms are typically characterized by the explosion of high energy events, which are seldom recorded in the databases of space missions; as a consequence, supervised methods are trained on very imbalanced historical sets, which makes them particularly ineffective for the forecasting of intense flares. Yet, in this study we show that supervised machine learning could be utilized in a way to send timely warnings about the most violent and most unexpected flaring event of the last decade, and even to predict with some accuracy the energy budget daily released by magnetic reconnection during the whole time course of the storm. Further, we show that the combination of sparsity-enhancing machine learning and feature ranking could allow the identification of the prominent role that energy played as an Active Region property in the forecasting process.