Solar and Helieospheric Physics

The Sun is the unique star we are living with. The solar atmosphere is a stratified atmosphere, which involves various layers: cool and dense photosphere and chromosphere, transition region with intermediate temperature and density, and hot and sparse corona. The solar atmosphere is always in dynamic state rather than in static state. Transient events, e.g., various types of waves and magnetic reconnection, are taking place almost everywhere in the atmosphere, and playing a crucial role in accelerating, heating and ionizing the solar atmosphere.

The solar wind is the magnetized plasma emitted at the outer atmosphere of the Sun. The solar wind fills the entire interplanetary space of the heliospheric system, and shapes the comet plasma tails away from the Sun. Disruptions of the solar wind greatly impact the solar-terrestrial space, and even to Earth’s space environment, exerting effects to our life and living.



Left: Solar corona, including active regions and polar coronal holes, in soft x-ray taken by SXT/Yohkoh. Right: Cartoon of spacecraft trajectories in the heliosphere containing the planets and bounded by the heliopause and interstellar medium. (photo credit on right: