空间科学学报
空間科學學報
공간과학학보
CHINESE JOURNAL OF SPACE SCIENCE
2010年
1期
9-16
,共8页
TC-1观测%近地磁尾%尾向流%偶极化
TC-1觀測%近地磁尾%尾嚮流%偶極化
TC-1관측%근지자미%미향류%우겁화
TC-1 exploration%Near-Earth tail%Tailward flow%Dipolarization
2004年10月12日,在01:30-04:30 UT期间,位于向阳侧磁层顶附近的 Geotail 卫星探测到行星际磁场为持续南向.此太阳风条件驱动了一个小磁暴,Symm-H指数在04:12 UT达到最小值-33 nT.在磁暴主相期间,AE指数维持在较高的水平,其最大值达400 nT. 02:00-03:00 UT期间,TC-1卫星在近地磁尾(-10.6,3.2,-0.1)R_e处观测到明显的亚暴膨胀相特征和磁场偶极化过程.在偶极化前1 min,有较强的(v_x<-100 km//s)持续时间超过3 min的尾向流发生.分析发现该尾向流具有低温、高密度和沿磁场流动的特点,这说明尾向流具有来源于电离层风的特征.尾向流期间,TC-1观测的磁场分量B_X>和总的磁场强度增加,磁倾角减小,磁场结构变成非偶极型,说明尾向流对磁场结构有一定的影响,文中尝试给出了相应的物理解释.观测表明,该事例中的近地磁尾尾向流可能对磁场偶极化过程的发生有重要意义.
2004年10月12日,在01:30-04:30 UT期間,位于嚮暘側磁層頂附近的 Geotail 衛星探測到行星際磁場為持續南嚮.此太暘風條件驅動瞭一箇小磁暴,Symm-H指數在04:12 UT達到最小值-33 nT.在磁暴主相期間,AE指數維持在較高的水平,其最大值達400 nT. 02:00-03:00 UT期間,TC-1衛星在近地磁尾(-10.6,3.2,-0.1)R_e處觀測到明顯的亞暴膨脹相特徵和磁場偶極化過程.在偶極化前1 min,有較彊的(v_x<-100 km//s)持續時間超過3 min的尾嚮流髮生.分析髮現該尾嚮流具有低溫、高密度和沿磁場流動的特點,這說明尾嚮流具有來源于電離層風的特徵.尾嚮流期間,TC-1觀測的磁場分量B_X>和總的磁場彊度增加,磁傾角減小,磁場結構變成非偶極型,說明尾嚮流對磁場結構有一定的影響,文中嘗試給齣瞭相應的物理解釋.觀測錶明,該事例中的近地磁尾尾嚮流可能對磁場偶極化過程的髮生有重要意義.
2004년10월12일,재01:30-04:30 UT기간,위우향양측자층정부근적 Geotail 위성탐측도행성제자장위지속남향.차태양풍조건구동료일개소자폭,Symm-H지수재04:12 UT체도최소치-33 nT.재자폭주상기간,AE지수유지재교고적수평,기최대치체400 nT. 02:00-03:00 UT기간,TC-1위성재근지자미(-10.6,3.2,-0.1)R_e처관측도명현적아폭팽창상특정화자장우겁화과정.재우겁화전1 min,유교강적(v_x<-100 km//s)지속시간초과3 min적미향류발생.분석발현해미향류구유저온、고밀도화연자장류동적특점,저설명미향류구유래원우전리층풍적특정.미향류기간,TC-1관측적자장분량B_X>화총적자장강도증가,자경각감소,자장결구변성비우겁형,설명미향류대자장결구유일정적영향,문중상시급출료상응적물리해석.관측표명,해사례중적근지자미미향류가능대자장우겁화과정적발생유중요의의.
On Oct.12,2004,the Geotail spacecraft was located in the solar wind near the day-side magnetopause and observed sustaining southward IMF from 01:30UT to 04:30 UT.During the interval,a weak storm is driven with minimum Sym-H index of -33 nT at 04:12 UT.In the main phase of the storm,AE index had been kept at a high level with a maximum value of about 400 nT.The TC-1 satellite located at (-10.6,3.2,-0.1) R_e observed evident characteristics of substorm expansion phase and the process of magnetic field dipolarization at the near-Earth magnetotail during 02:00-03:00UT.Prior to the dipolarization,tailward flow (v_x < -100 kin/s) lasting over 3 min with the characteristics of high hot ion temperature,low density and flowing along the magnetic field occurred.The features of the tailward flow indicated that it was originated from the ionosphere.During the interval of tailward flow,both the B_x component and the intensity of the magnetic field had been enhanced which suggested that the tailward flow had certain effects on the magnetic field configuration.According to the TC-1 observations,near-Earth tailward flow may be in close relation with the process of the magnetic field dipolarization.
