对自相似扩展(SSE)模型的改进和研究

	对自相似扩展(SSE)模型的改进和研究
	王晶晶 ; 罗冰显 ; 刘四清 ; 龚建村
刊名	地球物理学报
	2013
卷号	56 期号:9 页码:2871-2884
关键词	CME STEREO HI 角宽度
ISSN号	0001-5733
其他题名	Modification and study of self-similar expansion (SSE) model
通讯作者	北京8701信箱
中文摘要	自相似扩展拟合法(Self-Similar Expansion,SSE)假设日冕物质抛射(CME)具有恒定角宽度、沿径向向外传播的、自相似扩展的球形前沿,由日心出发的、与这个球形前沿相切的圆锥的圆锥角就是通常所说的CME角宽度,半角宽度取值范围是[0°,90°],固定Φ角拟合法(Fixed-Φ,FΦ)和调和均值拟合法(Harmonic-mean,HM)分别对应SSE模型的半角宽度为0°和90°的特殊情况.本文中修改后的自相似扩展拟合法(MSSE)假设CME具有自相似扩展的半球形前沿,能够提取的CME参数包括由日心出发的、圆锥截面过球心的圆锥的半圆锥角和CME的主传播方向、传播速度,其中半圆锥角取值范围是[0°,90°],FΦ和HM分别对应MSSE模型的半圆锥角为0°和45°的特殊情况,半圆锥角为90°时,CME前沿是以日心为圆心的半圆.MSSE拟合法扩大了SSE模型对CME前沿形态的描述范围,将半圆锥角作为判断CME是否能够到达、何时到达某颗卫星的重要参数.基于单颗STEREO卫星日球层成像仪(Heliospheric Imager,HI)图像,结合STEREO和ACE卫星的太阳风实地观测数据,本文深入分析了2010年23个CME事件,结果发现:在用于预报CME事件是否能到达某颗卫星、何时到达时,MSSE拟合法相比FΦ、HM和SSE拟合法,不但可以更准确地拟合CME主传播方向和传播速度,也可以缩小预计到达时间和到达速度的误差.
英文摘要	Self-Similar Expansion (SSE) fitting models the leading edge of the Coronal Mass Ejection (CME) as a self-similar expansion sphere with a fixed propagation direction and a fixed angular width. Cone angle of the heliocentric cone which is tangent to the sphere usually refers to the angular width of the CME, ranging from 0 to 90 degrees. Angular widths of Fixed-Φ (FΦ) and Harmonic-mean (HM) fitting are defined, corresponding to 0 and 90 degrees of SSE model, respectively. Modified SSE (MSSE) fitting discussed in this paper models the leading edge of the CME as a self-similar expansion semi-sphere. It is able to extract CME parameters using MSSE fitting, including propagation direction, velocity and cone angle of the heliocentric cone, whose conic section is across the center of the semi-sphere, ranging from 0 to 90 degrees. Cone angles of FΦ and HM fitting are defined, corresponding to 0 and 45 degrees of MSSE model, respectively. Leading edge of the CME can be assumed as a heliocentric semi-sphere when cone angle is assumed to be 90 degrees. MSSE fitting expands the morphology of leading edge of the CME and considers cone model as a reference to determine whether and when the CME will reach a satellite. 23 CMEs were analyzed based on the observations by Heliospheric Imager (HI) from one spacecraft of STEREO, combined with in-situ observations of solar wind on STEREO and ACE. We found that the error of the CME propagation direction, arrival speed and theoretical arrival time analyzed by MSSE fitting decreased, compared to FΦ, HM and SSE fitting.
学科主题	空间环境
资助信息	国家重点基础研究计划(2012CB825606和2011CB811406)和国家重点实验室专项基金
语种	中文
内容类型	期刊论文
源URL	[http://ir.cssar.ac.cn/handle/122/478]
专题	国家空间科学中心_空间环境部
推荐引用方式 GB/T 7714	王晶晶,罗冰显,刘四清,等. 对自相似扩展(SSE)模型的改进和研究[J]. 地球物理学报,2013,56(9):2871-2884.
APA	王晶晶,罗冰显,刘四清,&龚建村.(2013).对自相似扩展(SSE)模型的改进和研究.地球物理学报,56(9),2871-2884.
MLA	王晶晶,et al."对自相似扩展(SSE)模型的改进和研究".地球物理学报 56.9(2013):2871-2884.