【作者】 王晶晶；

【导师】 龚建村； 刘四清；

【作者基本信息】 中国科学院研究生院（空间科学与应用研究中心） ， 空间物理学， 2011， 硕士

【摘要】 STEREO-BEHIND(STB)、STEREO-AHEAD(STA)卫星分别位于ACE卫星的前、后方绕太阳公转，且二者与太阳的夹角逐日增大。冕洞发出的高速太阳风形成的相互作用区(CIR)，将依次扫过STB、ACE和STA卫星，目前，ACE卫星的太阳风观测是预报地球空间环境扰动的直接依据。本文根据2007-2009年STB、ACE和STA卫星的行星际磁场和太阳风数据，研究了CIR事件特征物理量的统计特征，和太阳风速度观测的相似度随时间和经度差异引起的观测时间滞后的变化特征，得到了如下结论：（1）随着卫星分离角的逐渐增大，STB、ACE和STA对每27天的太阳风速度观测数据的相关系数逐渐减小，在2007、2008和2009年STB和ACE卫星太阳风速度观测数据的相关系数均值分别为0.93、0.85和0.74。（2）STB和ACE卫星观测的CIR事件太阳风速度最大值的线性相关系数达到了0.84。（3）这些分析结果表明，STB和ACE卫星观测到CIR事件有很强的相似性。基于冕洞高速流从太阳向外匀速径向传输假设，本文讨论了随着STB和ACE与太阳之间的夹角从0°增大至70°时，CIR依次扫过STB和ACE的时间差特性，并统计分析了两颗卫星观测到的冕洞高速流参数的变化特征，得到如下结论：（1）可以利用STB对CIR事件的观测时间、以及高速流的速度最大值来预测这个CIR事件到达地球的时间。STB和ACE卫星先后观测到的CIR事件对的时间误差的平均值和最大值分别为0.217天和0.952天。时间误差的幅度随着卫星分离角的增大而增大，用速度差异矫正后，时间误差的平均值和最大值可分别减小为0.194天和0.489天。（2）STB和ACE卫星观测到CIR事件对特征物理量中速度、质子温度的变化最小，而质子密度、总压力的变化最大。随着卫星夹角的增大，CIR事件速度最大值、质子温度对数的最大值、总压力最大值、磁场强度最大值、磁场南向分量最大值的实测差异的变化幅度逐渐增大、平均值也逐渐增大，而质子密度最大值的实测差异的变化幅度和平均值却逐渐减小。（3）这些分析结果表明，STB卫星对CIR事件的观测可以作为ACE卫星观测CIR事件特征的参考，从而为地球空间环境扰动预报提供依据。本文也分析了分别持续25个和27个太阳自转周（CR）的两组同源重现性CIR事件的特征参数随着时间的变化特征，和它们相应高速流的源——冕洞在背景卡林顿经度上的变化特征，以及它们的特征参数在SI附近演变的统计特征，得到了如下结论：（1）这两组重现性CIR事件的源——冕洞在背景卡林顿经度上以每个CR约4.5°的速度向经度增大的方向运动。（2）样本1和样本2中的CIR事件的特征物理量有明显的生长、成熟和衰弱阶段，且三颗卫星在一个CR内实测数据的变化幅度在各阶段也是存在差异的。（2）同源CIR事件特征参数在SI附近的演化有明显的相似性。（3）上述分析结果表明，同源CIR事件的特征物理量在一个CR内被三颗卫星先后观测到的实测数据的变化幅度在生长、成熟、衰弱阶段有明显的差异，可以作为利用STB卫星的CIR观测预报到达地球处的重现性CIR事件特征的参考。更多还原

【Abstract】 STEREO-BEHIND(STB) and STEREO-AHEAD(STA) drifted behind and ahead of ACEaround the Sun, with longitudinal separation increasing day by day. CIR driven by high speedsolar wind from coronal holes swept STB, ACE, and STA sequentially. Currently, solar windobservations on ACE are the direct basis for Earth space environment forecasting.Based on interplanetary magnetic field and solar wind observations on STB,ACE and STA,statistical characteristics of CIR parameters and similarity of solar wind velocity observationswas discussed. It was found that: (1)Linear correlation coefficient of wind velocity observationsin each 27-day on STB, ACE and STA decreased with longitudinal separation. Average of linearcorrelation coefficient of wind velocity observations on STB and ACE in 2007, 2008 and 2009was 0.93, 0.85 and 0.74, respectively. (2)Linear correlation coefficient of maximum CIR speed onSTB and ACE was 0.84. (3)These results showed that, there was a strong similarity between CIRobservations on STB and ACE.Assuming high speed stream transmitted uniformly and radially from coronal holes,characteristics of CIR travel time from STB to ACE with their longitudinal separation increasedfrom 0°to 70°was discussed. Statistical variation characteristics of high speed stream parameterswas analysed. It was found that: (1)CIR arrival time on ACE could be predicted by CIRobservations on STB. The average and maximum errors of travel time was 0.217 day and 0.952day, respectively. The maximum errors of travel time increased with longitudinal separation. Theaverage and maximum errors of travel time reduced to 0.194 day and 0.489 day respectively aftercorrected by speed variances. (2)Characteristic parameters of the same CIR on STB and ACEsuch as speed and proton temperature showed the least difference, while proton density and totalpressure showed relatively large difference. The average and maximum range of difference onCIR characteristic parameters observed by STB and ACE, such as maximum speed, maximumproton temperature, maximum total pressure, maximum magnetic field and maximum magnetic southward components, increased with longitudinal separation, while they decreased onmaximum proton density. (3)These results showed that, CIR observations on STB could be usedas reference of CIR characteristics on ACE, and provided basis for forecasting of Earth spaceenvironment disturbance.Characteristics of parameters in two samples of recurrent CIRs which lasted for 25 CR and27 CR and came from the same coronal hole respectivelywas discussed. Characteristics ofsources of these samples, coronal holes, was discussed in Backmapped Carrington Longitude.Statistical characteristics of CIR parameters evolution around SI in these samples was analysed. Itwas found that: (1)Sources of these samples, coronal holes, moved at 4.5°per CR toward thedirection of longitude increasingly in Backmapped Carrington Longitude. (2)There wassignificant characters of CIR parameters and range of differences in CIR parameters observed bymulti-spacecraft between growth phase, maturation phase and decay phase in these samples.(3)These results showed that, the significant characters of range of differences in CIR parametersbetween growth phase, maturation phase and decay phase in recurrent CIRs from the samecoronal holes could be used as reference of CIR characteristics on ACE.更多还原