Magnetospheric physics in China: 2008—2010

In the past two years, most of the works on magnetospheric physics were made by using the data of Double Star Program and Cluster missions. However some works were still conducted by computer simulation or using the data from other space missions and ground geomagnetic observations. This paper briefly review these previous works based on papers selected from the 28 publications from April 2008 to April 2010. The subjects covered various sub-branches of magnetospheric physics, including geomagnetic storm, magnetospheric substorm and etc.      

Initial phase of mid-latitude aurora during strong geomagnetic storms

Analysing the initial mid-latitude aurora phase during strong geomagnetic storms we found that the initial phase of the mid-latitude aurorae observed at 630 nm emission during the strong geomagnetic storms on March 24, 1991, April 6, 2000, October 30 and November 20, 2003 is characterized by a short (∼1 h) wave-like disturbance. This disturbance corresponds to the beginning of main phase of the magnetic storms. The marked effect of the mid-latitude aurorae is analyzed using data on magnetosphere and ionosphere conditions in observation periods. The features of the dynamics of the 630 nm emission intensity and its connection with the dynamics of magnetospheric–ionospheric structures are considered. Possible excitation mechanisms of the atomic oxygen emission (630 nm) during these disturbances are discussed.     

卫星磁层亚暴环境模拟试验设备的设计

卫星表面充电是七十年代初发现的严重危害同步轨道卫星的新问题。为了寻求解决卫星表面充电问题的方法,许多国家进行了广泛的研究。我们于82年开展卫星表面充电模拟试验技术研究。本文仅就我们在磁层亚暴环境模拟设备设计中考虑的一些问题作简要介绍。阐述了对模拟系统的要求,模拟系统的组成和用途,介绍了真空系统,电子枪,光源和测量系统设计中应考虑的问题。     

2004年11月一次磁暴期间全球电离层TEC扰动分析

利用全球分布的GPS原始观测数据提取的电离层总电子含量(TEC)分析了2004年11月6日至12日期间全球电离层暴的形态特点与发展过程.结果表明,11月8日磁暴主相期间电离层暴以大范围的强烈正暴为主,在11月10日的恢复相,Dst又一次降到最低值前后期间,电离层再次受到很强的扰动,大范围的正暴和负暴交替出现.这次磁暴期间夏季半球的负暴更加强烈,反映出负暴偏向于在夏季半球发生的季节变化特点.另外,磁暴期间,夜晚TEC值普遍比磁暴前的平静期要低,具体是什么机制导致还需要进一步收集数据和分析.      

1998年10月18——-19日磁暴主相的行星际源分析

采用高时间分辨率的地磁指数SYM-H, 同时考虑日地连线引力平衡点(L1点)太阳风地磁效应的滞后性, 精确分析了1998年10月18---19日大磁暴主相的行星际源. 分析结果表明, 磁暴主相的行星际源仅为行星际激波和行星际日冕物质抛射之间的太阳风(Sheath), 磁云对磁暴主相没有贡献. 这个磁暴事例的研究表明, 行星际磁场南向分量与太阳风动压的乘积是影响磁暴主相发展的关键参数.      

Effects observed in the equatorial and low latitude ionospheric F-region in the Brazilian sector during low solar activity geomagnetic storms and comparison with the COSMIC measurements

The main objective of the present investigation has been to compare the ionospheric parameters (NmF2 and hmF2) observed by two ground-based ionospheric sounders (one at PALMAS- located near the magnetic equator and the other at Sao Jose dos Campos-located in the low-latitude region) in the Brazilian sector with that by the satellite FORMOSAT-3/COSMIC radio occultation (RO) measurements during two geomagnetic storms which occurred in December 2006 and July 2009. It should be pointed out that in spite of increasing the latitude (to 10°) and longitude (to 20°) around the stations; we had very few common observations. It has been observed that both the peak electron density (NmF2) and peak height (hmF2) observed by two different techniques (space-borne COSMIC and ground-based ionosondes) during both the geomagnetic storm events compares fairly well (with high correlation coefficients) at the two stations in the Brazilian sector. It should be pointed out that due to equatorial spread F (ESF) in the first storm (December 2006) and no-reflections from the ionosphere during nighttime in the second storm (July 2009), we had virtually daytime data from the two ionosondes.     

用银河宇宙线判定几个引起特大磁暴CME的运动方向

利用位于南北极尖区位置的McMurdo和Thule台站的宇宙线强度的观测数据，分析了几个引起特大磁暴CME的来向．分析结果表明，所选的与4个特大磁暴相关的CME基本是朝正对磁层顶的方向运动并与磁层作用的．通过对引起第23周两个特大磁暴的CME特征分析对照，发现CME的来向是影响磁暴强弱的一个因素．同样条件下，运动方向偏向地球一侧的CME引起的磁暴比正对地球的CME引起的磁暴要弱。     

地球资源技术卫星地面轨迹控制原理及调轨周期的选择

1.引言 在整个任务执行期间,要求资源卫星在一个复盖周期里的地面轨迹中心线与另一个复     

上游太阳风中高能电子向同步轨道区的传输

通常认为，同步轨道区的电子通量增加是由于磁暴或者上游太阳风高速流的扰动所引起．近来的观测表明，起源于太阳活动的行星际高能电子也是引起同步轨道电子通量增加的重要原因之一．Zhao等在研究2000年7月14日太阳剧烈活动时发现，同步轨道区相对论电子通量巨幅增加时没有观察到上游太阳风高速流的扰动，并且磁暴发生在电子通量事件之后．采用解析磁场模型和实际磁场模型(T96模型)模拟来自太阳的相对论电子在磁尾中的运动特性．计算结果表明，当行星际磁场南向时，进入到磁尾的行星际相对论电子可以从较远的磁尾区域运动到同步轨道区域．这一研究结果从理论上论证了起源于太阳活动的高能电子可以对同步轨道区相对论电子通量的增加产生重要的作用．     

Response of the low latitude geomagnetic field to the major proton event of November 2001

A major solar flare eruption occurred at 16:20 UT on 4 November 2001, followed by strong solar radiation storm and proton event recorded by the SOHO and other interplanetary satellites. Coronal mass ejection associated with the flare event triggered an interplanetary shock, which impacted the geomagnetic field after about 33 h. The shock impact was quite intense to produce a SSC magnitude of 80 nT in the low latitude ground magnetic records followed by sharp and deep main phase (Dst −300 nT) in the first stage, following the density (N_p) enhancement. High time resolution digital magnetic field data from the equatorial and low latitude stations in India are analyzed to study the influence of various IP parameters on the intensity and duration of the magnetic storm. A double step storm was found to be in progress caused by the multiple injections. During the period of recovery, after a period of 8 h, a third stage of depression in the ground magnetic field was set in, which corresponded to the southward directed Bz. The energy transfer processes associated with the event is presented.