The solar atmosphere can reach a temperature of 1 million Kelvin or even higher. Since the gas in the solar corona is so hot, it becomes ionized into a plasma state and streams continuously and radially away from the Sun into interplanetary space together with the solar magnetic field. The solar atmosphere can also be eruptive and releases a significant amount of energy in various forms such as radiations in the UV, X-ray, and gamma-ray ranges, shock waves, dense plasmas, magnetic clouds, and energetic particles within a short time of about minutes to hours.
The solar activity influences not only the immediate neighborhood region of the Sun, but also the whole plasma domain up to the edge of the solar system by means of the solar wind stream and the interplanetary magnetic field. For example, interplanetary dust particles become ionized and change the orbits in the local magnetic fields; and the solar wind interacts with the planetary atmospheres, magnetospheres, and even the surfaces.
The heliosphere group at IWF is working on the fundamental research areas on the solar and heliospheric physics. In particular, the following questions are addressed:
- How does the solar eruption propagate into interplanetary space?
- What kinds of waves and instabilities exist in the solar wind plasma?
- How does the solar wind plasma evolve into turbulence and shock waves?
In order to answer those questions, various research methods are used, such as in situ spacecraft measurements in interplanetary space and planetary magnetospheres and numerical simulations (and also data-driven simulations) on the plasma processes.