%0 Journal Article
%T Azimuthal magnetic field disturbances and spiral structure of the interplanetary magnetic field<br>日面方位磁场扰动和行星际磁场螺旋结构
%A HU You-Qiu ZHENG Guo-HuiSchool of Earth
%A Space Science
%A University of Science
%A Technology of China
%A Hefei
%A China
%A <br>胡友秋
%A 郑国辉
%J 地球物理学报
%D 2004
%I 
%X A 2.5 dimensional, ideal MHD model in spherical coordinates is used to numerically simulate the propagation of azimuthal magnetic field disturbances with emphasis upon its influence on the spiral angle of the interplanetary magnetic field (IMF). The observed fact that the IMF spiral angle is larger than that predicted by the Parker model is attributed to a ceaseless launching of azimuthal magnetic field disturbances of the same sign from the solar surface. The differential rotation of the Sun induces an azimuthal magnetic field inside the Sun, providing a source for these disturbances. The simulation results show that azimuthal magnetic field disturbances of the same sign which have a duration of one tenth of the period and an amplitude of order of 103nT is capable of increasing the IMF spiral angle at 1AU by 2° so as to match with relevant observations. It is also shown that the azimuthal magnetic field disturbances mentioned above have little effect on the solar wind properties and the magnetic configuration in the heliospheric meridional plane.
%K Heliospheric dynamics
%K Interplanetary magnetic field
%K MHD simulation<br>日球动力学
%K 行星际磁场
%K MHD数值模拟
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=1E44AE713D8A6DE0&jid=14DC41C59CBF6770055A7D610D53AE46&aid=B6E1F2933B5B9B80&yid=D0E58B75BFD8E51C&vid=F4B561950EE1D31A&iid=E158A972A605785F&sid=811ACA5D3673A764&eid=D8414BC1307BF1A3&journal_id=0001-5733&journal_name=地球物理学报&referenced_num=0&reference_num=14