April 15, 2003
Tuesday - 4:00pm in Swain West 238
Speaker: Maya Paczuski (Imperial College)
Images: image 1
Title: Explosions on the Sun: Solar flares as cascades of reconnecting magnetic loops

Abstract:
Solar flares are bursts of intense radiation from the corona, caused by the sudden release of coronal magnetic energy due to reconnection. Robust power-laws have been observed for the distribution of energy released in flares, the time intervals between them, etc. suggesting that the corona is in a self-organized critical state. We introduce a model of the solar coronal magnetic field where multiple directed loops evolve in space and time. Energy is fed into the system by the addition of new loops and stirring of footpoints. When two loops collide they may reconnect, possibly triggering a cascade of further reconnection. The model reproduces the scaling behavior for flare statistics as well as some geometrical features of the coronal magnetic field. We predict that the distribution of net, signed magnetic flux in grid cells imposed on the photosphere is also power law.