A sketch of solar physics.
Abstract
Solar physics is an important, exciting branch of science in three ways. To begin with, solar phenomena and the physics that governs them are fascinating and worthy of study in their own right. The length scales, temperatures, densities, magnetic fields, gravity, and rotation of the Sun yield an array of magnetohydrodynamic (MHD) phenomena that are captivating to observe, confounding to explain, and impossible to truely replicate in the laboratory. In another way, solar physics is important because the Sun is the nearest star. This makes our knowledge and understanding of the Sun, i.e., solar physics, a key to stellar astrophysics. Moreover, as in the MHD and plasma phenomena of the Sun, magnetized plasma is an essential ingredient of most cosmic systems of stellar and galactic scale, including the violent objects prominent in modern astrophysics (e.g., collapsed stellar objects with accretion disks, active galactic nuclei, and stellar and galactic jets). Because of this and the nearness of the Sun, solar physics guides and tests our understanding of processes that are important for much of astrophysics beyond that of normal stars. Finally, solar physics is important because the Sun, through its direct radiation and the solar wind, is the origin or driver of phenomena central to space physics: the interplanetary medium and the magnetospheres, ionospheres, and atmospheres of the planets. This domain includes solar-terrestrial effects of great practical importance: the Sun sustains life on Earth, drives our weather, and regulates our climate. As in astrophysics, plasma processes that govern solar phenomena also pervade space physics. For example, this is evident in the strong similarity between solar flares and magnetospheric substorms (e.g., see Svestka, 1976). So, in broad perspective, solar physics is a worthy endeavor because solar physics by itself is a challenging and rewarding science, because solar physics (together with space physics) is a key to much of astrophysics, and because of the preeminence of the Sun in space physics phenomena and the terrestrial environment.
- Publication:
-
Geophysical Monograph Series
- Pub Date:
- 1989
- DOI:
- 10.1029/GM054p0001
- Bibcode:
- 1989GMS....54....1M
- Keywords:
-
- Sun: Physics;
- Solar Magnetic Fields