Space Weather and the Changing Sun

The free energy that drives space weather is created in the convective zone of the Sun with the generation and convective distortion of magnetic fields. The fields rise to the surface where they provide the vigorous suprathermal activity that is the direct parent of space weather. Some aspects of the hydrodynamics and magnetic field generation are understood, while there remains much that is mysterious. An important part of the mystery centers around the complex hydrodynamics of the convective zone and the dominating micro-scale magnetic fibril structure, motion, and interactions at the surface. The next generation Advanced Solar Telescope-the solar microscope- is intended to open up this basic small-scale world to direct observational study. The other major mystery lies in the long- term variations in the general level of solar activity, with the associated variations in space weather and terrestrial climate. Unfortunately long-term variation can be studied only in the long term, although monitoring other solar-type stars has been helpful so far in suggesting the extreme possibilities.