磁层顶附近流场剪切度的确定

	磁层顶附近流场剪切度的确定
	李凌寒 ; 陈涛
刊名	空间科学学报
	2008
卷号	28 期号:4 页码:273-282
关键词	磁层顶等离子体流剪切度
ISSN号	0254-6124
其他题名	Shear Rate Determination of Flow Near Magnetopause
通讯作者	北京8701信箱
中文摘要	磁层顶附近的流场剪切度与磁层顶附近能量转换的程度有关.很多磁层顶数值模拟用到流场剪切度这个输入参数,但一直是假设的.本文利用Cluster多卫星同时观测数据及独特的时空分辨功能,采用线性插值和重心坐标的方法确定了磁层顶附近流场的剪切度.通过对晨侧和昏侧磁层顶及附近磁层磁鞘流场剪切度的真实空间分布的研究结果表明,在平静的太阳风条件和地磁条件下磁层顶附近流场剪切度有时也很大,可达每百公里330km/s的相对速度差.但在很多情况下流场是弱剪切的,在上千公里的距离上只有每秒几十公里的相对速度差.本文确定流场剪切度的方法可以推广用来确定任一位置的流场剪切度.
英文摘要	Shear rate of flow near magnetopause is related to the degree of energy transfer near magnetopause.Many numerical simulations near magnetopause have to use shear rate of flow as an important input parameter.However,up to now it is still by pothetical and not realistic.By simultaneous multipoint observations of Cluster,using methods of linear interpolation and barycen-tric coordinates, we have determined shear rate of flow near magnetopause, an observational spatial parameter that can not be obtained until Cluster. Observational spatial distribution of shear rate of flow at dawn side and dusk side of magnetopause, magnetosphere and magnetosheath nearby has been analysed,Data analysis demonstrates that shear rate of flow as large as velocity difference of 330 km/s over the distance of 100 km can exist near magnetopause sometimes even under quiet solar wind and geomagnetic conditions.Under many circumstances shear rate of flow near magnetopause is small, with the spatial velocity difference of dozens of km/s over the distance of 1000 km.The method we have adopted here can be used widely to determine shear rate of flow at any location.
学科主题	空间物理
收录类别	CSCD
资助信息	国家自然科学重大基金项目,国家自然科学基金项目,优秀实验室重点基金项目,973重大基础项目
语种	中文
CSCD记录号	CSCD:3375305
内容类型	期刊论文
源URL	[http://ir.cssar.ac.cn/handle/122/1330]
专题	国家空间科学中心_空间科学部
推荐引用方式 GB/T 7714	李凌寒,陈涛. 磁层顶附近流场剪切度的确定[J]. 空间科学学报,2008,28(4):273-282.
APA	李凌寒,&陈涛.(2008).磁层顶附近流场剪切度的确定.空间科学学报,28(4),273-282.
MLA	李凌寒,et al."磁层顶附近流场剪切度的确定".空间科学学报 28.4(2008):273-282.