1. 学术报告：Magnetic reconnection in collsionless plasmas: 时间：2012年10月22日（星期一）下午3：00 地点：行政科研楼1514室 报告人：Prof. Dr. Jörg Büchner 单位：德国马普研究所(他是的space plasma simulation 和 plasma astrophysics and space physics两本书的编著者) 摘要： In 1946 Giovanelli first suggested that solar flares are due to the sudden release of magnetic energy in the solar atmosphere. Later the release of magnetic energy was related to the annihilation of agnetic flux, flux merging, reconnection through current sheets with the 2D resistive MHD model of Parker and Sweet in the 1950ties. In magnetospheres stationary 2D resistive MHD reconnection models like that of Petschek (1964) were applied to explain the solar wind energy entry, substorms et c.In the collisionless solar corona, however, the reconnection rates calculated in a similar way as for magnetospheres for the Spitzer resistivity and for the observed plasma motion velocities are too small to account for strong energy release. Now it has been understood that reconnection in chromosphere, transition region and corona is essentially different from 2D and MHD model predictions, it critically depends on the local plasma β and plasma turbulence at different scales. We will give examples and illustrate them by model calculation results for different types of solar coronal reconnection and compare them with observable signatures in energetic particles and electromagnetic waves.

李勤秀 Posted at 2012-10-19 08:11 CST Last modified at 2012-10-19 08:19 CST Link to this poster Top