摘要
作为空间天气扰动的源头,太阳爆发活动会在太阳大气中产生各种波动现象,这些波动不但传递着大量的能量,也携带了传播路径上磁场和等离子体的信息,因此对于太阳大气中波动现象的研究非常重要.在这些波动现象中,非常引人入胜的大尺度波动现象是太阳大气色球(紧靠太阳表面)中的莫尔顿波和日冕中的极紫外波.莫尔顿波主要表现为Hα线心和蓝翼图像中的增亮波前以及Hα红翼图像中的暗黑波前,速度在500~2000 km/s左右,极紫外波则表现为在极紫外图像中观测到增亮波前,速度从10 km/s到逾2000 km/s.莫尔顿波的产生机制方面的模型相对比较成熟,而极紫外波的产生机制、极紫外波与莫尔顿波之间的关系则一直是有趣而充满争议的话题.本文对莫尔顿波和极紫外波的研究进行综述,详细介绍莫尔顿波的发现、莫尔顿波早期的经典模型以及近年的进展、极紫外波的发现、极紫外波的各种观测特征以及极紫外波的众多理论模型.最后对莫尔顿波和极紫外波的研究进行展望,指出研究这些波动现象的意义.
Solar eruptions,which generate various types of wave phenomena in the solar atmosphere,are sources of space weather perturbations.These waves not only transport a large amount of energy,but also illuminate the properties of the magnetic field and plasma on the path of propagation.Therefore,it is of great interest to investigate wave phenomena in the solar atmosphere,among which Moreton waves in the solar chromosphere and extreme ultraviolet(EUV)waves in the corona have attracted much attention in the past few decades.Moreton waves are characterized by bright fronts in the Hαline center and blue wing(or dark fronts in the Hαred wing),which propagate at speeds ranging from~500 km/s to more than 2000 km/s.They were also observed in He I 10830Å.EUV waves are characterized by bright fronts in the EUV images,which propagate at speeds ranging from~10 km/s to more than 2000 km/s.Whereas the understanding of Moreton waves is rather mature,the nature of EUV waves and their relationship with Moreton waves are controversial and have been debated for more than two decades.Initially,it was proposed that EUV waves are the coronal counterparts of chromospheric Moreton waves;that is,they are fast-mode MHD waves.However,many EUV waves have been found to have speeds that are less than the sound speed,which means that some EUV waves cannot be accounted for by the fast-mode MHD wave model.Therefore,several alternate models have been proposed,such as slow-mode soliton waves,echoes of fast-mode waves,successive magnetic reconnection models,as well as hybrid models,which predict the existence of two components of EUV waves-a fast-mode and a slower pseudo-wave.The pseudo-wave is explained by the magnetic field line stretching model,which predicts that the fast-mode wave should be~3 times faster than the pseudo-wave.With later high-cadence observations,EUV waves with two components have been revealed in many events,confirming the validity of the hybrid model.However,recent observations have revealed many new features that deserve furth
作者
陈鹏飞
Chen Pengfei(School of Astronomy and Space Science,Nanjing University,Nanjing 210023,China;Key Lab of Modern Astronomy&Astrophysics(Nanjing University),Ministry of Education,Nanjing 210023,China)
出处
《地球与行星物理论评（中英文）》
2023年第4期355-371,共17页
Reviews of Geophysics and Planetary Physics
基金
科技部重大研发资助项目(2020YFC2201200)
国家自然科学基金资助项目(11961131002)。
关键词
太阳大气
色球
日冕
磁声波
日冕物质抛射
太阳耀斑
solar atmosphere
chromosphere
corona
magnetoacoustic waves
coronal mass ejections
solar flares
