Cluster Observation of Eelectrostatic Solitary Waves around Magnetic Null Point in Thin Current Sheet

Electrostatic solitary waves （ESWs） are observed in the vicinity of the magnetic null of the widely studied magnetic reconnection taking place at the near-earth tail when current sheet becomes dramatic thinning during substorm time on 1 October 2001. We use the Imada method for the 2-D reconnection model and study the characteristics of ESWs near the X-line region and the magnetic null points. The result shows that the amplitude of the observed ESWs in the vicinity of X-line region ranges from 0.1mV/m to 5mV/m, and the amplitude is larger near the magnetic null points. The generation mechanism and the role of ESWs associated with magnetic reconnection are also discussed.     

Storm-Time Strong Field-Aligned Ion Upflow in Region of the SED Plume

We report the observations from the GPS TEC and DMSP F-13 satellites showing that very strong upward field-aligned （FA） ion velocity and flux in the outer region of the storm-enhanced density （SED） occurred in the event of the geomagnetic storm on 29-31 May 2003. By a method of coordinate transformation, upward FA ion velocities in excess of 25Orals are obtained from the observations of the DMSP F-13 satellite. Further, an FA ion flux is estimated to be about 4.5 x 1013 ions/m2 s in the dusk sector. The estimated FA ion velocity and flux provide a powerful direct proof to support the scenario that there is a strong coupling of particles between the ionosphere and plasmasphere in the region of the SED plume. In the process, FA ion flux transports from the ionosphere to the plasmasphere in the region of the SED plume. Therefore, the plume of SED in the ionosphere provides an important source to the enhanced density of O^＋ in the storm-time plasmasphere.     

程控数字交换机计费系统电路设计

针对实际的程控数字交换机计费系统，设计了一种在计算机和程控数字交换机之间进行并行通信的接口电路．该接口电路由大规模集成电路器件构成．对其硬件电路组成及工作原理作了较为详细的阐述，对计算机数据接收程序的设计也作了必要的说明，并给出了程序流图．     

Alfven Waves in a Plasma Sheet Boundary Layer Associated with Near-Tail Magnetic Reconnection

We report observations from Geotail satellite showing that large Poynting fluxes associated with Alfven waves in the plasma sheet boundary layer （PSBL） occur in the vicinity of the near-tail reconnection region on 10 December 1996. During the period of large Poynting fluxes, Geotail also observed strong tailward plasma flows. These observations demonstrate the importance of near-tail reconnection process as the energy source of Alfven waves in the PSBL. Strong tailward （Earthward） plasma flows ought to be an important candidate in generating Alfven waves. Furthermore, the strong perturbations not only of the magnetic field but also of the electric field observed in the PSBL indicate that the PSBL plays an important role in the generation and propagation of the energy flux associated with Alfven waves.     

南极中山站宁静日午后极光事件分析

对１９９７ 年６ 月２ 日１１２７～１７００ ＵＴ,在南极中山站（不变地磁纬度为７４．５Ｓ,ＭＬＴ＝ ＵＴ＋ ２）利用全天空极光摄像机和三波段极光扫描光度计观测到的午后极光进行了分析,发现宁静日午后极光的形态随磁地方时变化．在午后早些时候,辉度较弱的冕状极光出现在中山站的极向侧和日向侧;随后出现的是来自日侧的带状极光,该结构东向传播,赤道向运动;在午后较晚的时候出现的是来自夜侧的带状极光．同时将午后极光与当地地磁观测、ＤＭＳＰ／Ｆ１１ 卫星的粒子观测以及ＷＩＮＤ卫星的ＩＭＦ观测进行了对照分析,认为宁静日午后极光中的分离结构是由来自磁层顶附近的粒子沉降产生的,其变化和运动与地磁Ｈ 分量和ＩＭＦＢｚ 分量的变化相关．     

通量修正法在日地空间MHD激波模拟中的应用

回顾了应用于日地空间磁流体力学模拟的多种数值方法．将通量修正（ＦＣＴ）法应用于一维球对称超音速太阳风和激波对的模拟，所得结果在物理上与文献相比符合很好．但得到的激波间断面比文献更精确，间断面网格点数在２～３个之间．此方法可推广到在多维情形下进行扰动的数值模拟．     

不需要校准激光的法-帕仪中高层大气温度反演方法和观测数据初步分析

本文提出了一种根据FPI观测不需要校准激光而进行温度反演的方法, 给出了进行温度反演的解的解析形式. 依据武汉大学FPI大气温度测量系统获得的630 nm和557.7 nm观测数据, 利用上述方法进行温度反演, 结果表明本文方法不需要校准激光, 能用于不同波长的FPI温度反演.     

地球等离子体边界层扰动的小波分析方法

利用ClusterⅡ卫星的磁场数据，采用小波联合参数估计方法，研究了地球等离子体边界层磁场扰动的多尺度特征，计算了指定尺度内的等离子体边界层中扰动的相对功率，对2001年10月1日发生的磁场重联事件进行了分析．结果显示：在小尺度时间段（≈0．24～1．00s）和大尺度时间段（≈0．96～4．00s）磁场在09：40～09：50UT的扰动很强烈，而且具有间断性；在09：30UT和10：00UT时间点前也有较小的扰动．将该事件与2002年9月18日的非磁场重联事件数据分析结果比较，证实了小波参数估计能够很好地有效地快速地分析磁尾磁场数据的多尺度的扰动现象．