What geometrical factors determine the in situ solar wind speed?  

作　　者：LI Bo CHEN Yao XIA LiDong 

机构地区：[1]Shandong Provincial Key Laboratory of Optical Astronomy ＆ Solar-Terrestrial Environment, School of Space Science and Physics, Shandong University at Weihai, Weihai 264209, China [2]State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100190, China

出　　处：《Chinese Science Bulletin》2012年第12期1409-1414,共6页

基　　金：supported by the National Natural Science Foundation of China(40904047,40825014,40890162 and 40974105);the Specialized Research Fund for State Key Laboratories

摘　　要：At present it remains to address why the fast solar wind is fast and the slow wind is slow.Recently we have shown that the field line curvature may substantially influence the wind speed v,thereby offering an explanation for the Arge et al.finding that v depends on more than just the flow tube expansion factor.Here we show by extensive numerical examples that the correlation between v and field line curvature is valid for rather general base boundary conditions and for rather general heating functions.Furthermore,the effect of field line curvature is even more pronounced when the proton-alpha particle speed difference is examined.We suggest that any solar wind model has to take into account the field line shape for any quantitative analysis to be made.At present it remains to address why the fast solar wind is fast and the slow wind is slow. Recently we have shown that the field line curvature may substantially influence the wind speed v, thereby offering an explanation for the Arge et al. finding that v depends on more than just the flow tube expansion factor. Here we show by extensive numerical examples that the correlation between v and field line curvature is valid for rather general base boundary conditions and for rather general heating functions. Furthermore, the effect of field line curvature is even more pronounced when the proton-alpha particle speed difference is examined. We suggest that any solar wind model has to take into account the field line shape for any quantitative analysis to be made.

关 键 词：太阳风速度 几何因素 原位 磁力线 膨胀系数 边界条件 加热功能 速度差异 

分 类 号：P353.8[天文地球—空间物理学]