The Physics of the Solar Corona and Transition Region

The Sun's magnetic field is responsible for the spectacularly dynamic and intricate phenomenon that we call the corona. The past decade has seen an enormous increase in our understanding of this part of the solar outer atmosphere, both as a result of observations and because of rapid advances in numerical studies. The YOHKOH satellite has observed the Sun now for over six years, producing spectacular sequences of images that convey the complexity of the corona. The imaging and spectroscopic instruments on SOHO have added information on the cooler part of the corona. And since April of 1998 TRACE has given us very high resolution images of the 1-2 MK corona, at cadences that allow detailed observations of field oscillations, loop evolution, mass ejecta, etc. This volume contains papers contributed to a workshop (held in August 1999, in Monterey, California) that was dedicated to an exploration of the most recent results on the solar corona, as well as on the transition region and low solar wind. The diverse presentations at the meeting revolved around one key theme: the entire outer atmosphere of the Sun is intrinsically dynamic, evolving so rapidly that even the concept of a single local temperature for a single fluid often breaks down. Moreover, the corona is an intrinsically nonlinear and nonlocal medium. These aspects are discussed in these proceedings that include both papers that review recent developments (both based on observations and on theoretical/numerical modeling), and original research papers based on observations from many different observatories. The papers presented at the meeting add up to such a size that they are distributed over two Topical Issues of Solar Physics (December 1999 and April 2000), which are reprinted in these bound volumes.