文章基本信息

标题：Forecasting High-Speed Solar Wind Streams Based on Solar Extreme Ultraviolet Images
本地全文：下载
作者：X. Bu ; B. Luo ; C. Shen 等
期刊名称：Space Weather
印刷版ISSN：1542-7390
出版年度：2019
卷号：17
期号：7
页码：1040-1058
DOI：10.1029/2019SW002186
语种：English
出版社：American Geophysical Union
摘要：High-speed solar wind streams that originate from coronal holes play an important role in space weather disturbances, especially during the declining phase of the solar cycle. Space weather forecasters attempt to find good coronal hole indices that can be used to predict high-speed streams days in advance. Several indices related to the coronal hole area, brightness, or magnetic field expansion factor have been reported in the literature. Empirical solar wind forecast models have been developed and used in operational service by several organizations by constructing prediction functions that relate the coronal hole index to the solar wind speed. In this paper, we present a new empirical modeling method and test its validity by comparing it with a previously reported method when applied to different coronal hole indices. In total, six empirical models are tested for a long period of time (2011–2018), with a 27-day persistence model as a comparison benchmark. The results show that while all these empirical models can capture the temporal patterns of the solar wind observations well, the new modeling method and utilization of a composite coronal hole index PCH as an input parameter indeed improves the forecast accuracy. The high-speed streams can be predicted approximately 3 days in advance, with a probability of detection of 0.78, a positive predictive value of 0.73, and a threat score of 0.61. The uncertainty of the high-speed stream arrival time is approximately 1 day and the uncertainty of the peak speed is approximately 80 km/s.