数值模拟日侧磁场重联对极盖等离子体云块形成的影响  

Numerical simulation of the role of dayside magnetic reconnection in polar cap patch formation

作　　者：杨升高[1,2] 张北辰[2] 张清和[3] 方涵先[1] 刘俊明[2] 周霄林 张建彬 

机构地区：[1]解放军理工大学气象海洋学院 [2]中国极地研究中心 [3]山东大学空间科学与物理学院 [4]61741部队气象中心气象保障室 [5]63655部队五室

出　　处：《地球物理学报》2014年第11期3551-3557,共7页Chinese Journal of Geophysics

基　　金：国家重点基础研究发展计划(2012CB825603);国家自然科学基金(41104090;41274148;40505005;41431072;41274149);国家重点实验室专项基金(Y22612A33S);南北极环境综合考察与评估专项(CHINARE-2014-02-03)资助

摘　　要：极盖等离子体云块是极区空间天气重要现象之一,其形成过程是当前重要研究课题.观测表明,日侧磁场重联对应的极区电离层高速流可能对舌状等离子体(TOI)形成"切割"作用,最终形成极盖等离子体云块.伴随磁场重联,同时存在极光粒子沉降,会引起F层等离子体密度的增大,阻碍"切割"效应.本文利用耦合极区电离层模型,模拟研究电场和软电子沉降共同作用下F层等离子体密度的演化.结果表明,在局部电离层电场大于一定数值(80mV)的情况下,"切割"效应能有效发生.并详细分析了"切割"效应发生时等离子体各参量的演化过程,对"切割"效应的内在物理过程进行了探讨.As a significant polar space weather phenomenon, the polar cap patch formation is one of the important research subjects. Observations suggest that the strong convection flow due to the dayside magnetic reconnection has a ＂breaking off＂ effect on the TOI （Tongue of ionization）, as a result the polar cap patch is formed. However, the auroral particles precipitation increasesthe F region electron density, which will block the ＂breaking off＂ effect. Based on a self- consistent model of polar ionosphere, this paper simulated the F region plasma density evolution under the combined effect of soft precipitation and electric field. The results show that when local electric field is more than 80mV, the ＂breaking off＂ occurs effectively. Also, we analyzed the evolution of various plasma parameters in the process of the ＂breaking off＂, and discussed its internal physical mechanism.

关 键 词：极盖等离子体云块 磁重联 对流电场 

分 类 号：P352[天文地球—空间物理学]