太阳是距离地球最近的恒星,不仅对于日地空间环境具有重要的影响,而且作为独一无二的天然等离子体实验室,有助于理解宇宙中电磁相互作用的基本过程.螺度作为描述矢量场属性的基本参量,在理解太阳物理研究的核心课题——太阳磁场的起源和磁场能量的释放机制方面具有重要意义.本文探讨了螺度的基本概念(包括磁螺度、电流螺度、运动学螺度等),以及我国太阳物理学家在螺度研究中的主要进展,并对未来太阳物理中螺度研究的问题做了一些探讨.
The Sun is the nearest star to the Earth. The Sun not only affects the environment of interplanetary space but, as a unique large-scale natural plasma laboratory, also helps us understand the basic process of electromagnetic interaction in the universe. Helicity is a basic parameter to describe the properties of vector fields. It is important in understanding the origin of the solar magnetic field and the release mechanism of solar magnetic energy, which are key subjects in solar physics. In this paper, we discuss the basic concepts of helicity (including magnetic helicity, current helicity, and kinematic helicity) and major advances in helicity research. Based on these information, we raise new open questions regarding the helicity research of solar physics.