摘要
本文统计研究了第20太阳周内持续时间≥1.5小时的主要耀斑所引起的1天文单位处瞬交流的MHD特性。着重比较亮耀斑与非亮耀斑产生的瞬交流及其与共转流特性上的差别。亮耀斑与非亮耀斑瞬交流的主要差别是前者的磁压力相对于热压力和动能密度的比值均明显地增高,而后者则反比背景值有所降低。亮耀斑瞬交流与共转流的主要差别是前者的前部磁马赫数较低,而后部则声马赫数较高,而共转流则始终具有低声马赫数和磁马赫数的特点。
The MHD characteristics of the transient streams generated by major solar flares, defined as the flares of importance ≥2 with a duration longer than 1.5 hours observed at 1 AU during the 20th solar cycle, are studied in this paper. The discussions emphasize the difference in properties among the streams generated by the bright and the non-bright flares and the corota-ting streams. The ratios of the magnetic to the thermal pressure and to the kinetic energy density increase significantly within the transient streams generated by the bright flares, and decrease within those generated by the non-bright ones. The main differences between the transient streams generated by the bright flares and the corotating streams are: the former are streams with relatively lower speed and magnetic Mach numbers followed by high speed streams with higher value of thermal sonic Mach numbers, while the latter are always high speed streams with lower Mach numbers.
基金
国家自然科学基金
关键词
太阳
耀斑瞬变流
MHD特性
Sun (the): flares-Transient streams-MHD characteristics
