Modeling the Solar Dynamo

摘要

The Sun's magnetic field is the engine and energy channel underlying virtually all manifestations of solar activity. Its evolution takes place on a wide range of spatial and temporal scales, including a prominent 11-year cycle of successive polarity reversals over the entire star. This magnetic cycle in turn modulates the physical properties of the plasma flowing away from the Sun into interplanetary space, the frequency of all geoeffective eruptive phenomena (such as flares and coronal mass ejections), and the solar radiative flux over the full range of the electromagnetic spec- trum-from x-rays through ultraviolet, visible, and infrared light, all the way down to radio frequencies (1). The Sun's heartbeat is truly magnetic, and recent numerical simulations (2-5) are providing new insights into its mode of operation.