1. Supergranulation Here is a little story. I donot know why I still remember this picture (I almost have no memory). The first sight is in a senior lecture in 2005 Fall, the last semester of my undergraduate study. And I ask the lecturer why the limb part is more distinct than the center part. Actually this photo shows the velocity pattern of supergranulations. At the centre, the flow generally rise at a typical velocity of 0.1km s^-1, meanwhile moves horizontally outwards at 0.3-0.4km s^-1. And it descends at the edge of cells at 0.1-0.2km s^-1. Near the limb, the doppler shift image is dominated by horizontal velocity, greater than vertical velocity at the centre. An 'opposite' example is limb darking. The size of supergranulation: diameter 20000-54000 km with an average at 32000km. last 1-2 days 图片来源 http://spacescience.spaceref.com/ssl/pad/solar/default.htm [1]

Fan Guo Posted at 2007-10-10 07:17 CST Last modified at 2007-10-11 06:03 CST Link to this poster Source Code Top