地球物理学报
地毬物理學報
지구물이학보
2001年
1期
12-23
,共12页
洪明华%汤克云%胡红桥%刘瑞源
洪明華%湯剋雲%鬍紅橋%劉瑞源
홍명화%탕극운%호홍교%류서원
高纬极光弧%磁层亚暴%IMF%南极中山站
高緯極光弧%磁層亞暴%IMF%南極中山站
고위겁광호%자층아폭%IMF%남겁중산참
利用南极中山站极光全天空摄相、地磁、地磁脉动数据和Wind卫星的行星际磁场IMF观测数据,分析了7个亚暴期间高纬黄昏—子夜扇区极光弧的短暂增亮现象.极光弧特征是,短暂增亮随后很快衰减,历时10—20min,基本沿着日-地方向,有明显黄昏方向运动.这些事件大都发生在IMFBz南转之后,亚暴增长相或膨胀相期间,极光浪涌到达之前10—73min消失.相应的IMFBx>0,IMFBy<0.这种极光弧和亚暴极光不同,它们与地磁活动及Pi2脉动不相关.这7个极光弧的形态和IMF特征表明,极光弧的增亮很可能由尾瓣重联产生,很快衰减归因于IMFBz南向条件,而黄昏方向运动受IMFBy控制.
利用南極中山站極光全天空攝相、地磁、地磁脈動數據和Wind衛星的行星際磁場IMF觀測數據,分析瞭7箇亞暴期間高緯黃昏—子夜扇區極光弧的短暫增亮現象.極光弧特徵是,短暫增亮隨後很快衰減,歷時10—20min,基本沿著日-地方嚮,有明顯黃昏方嚮運動.這些事件大都髮生在IMFBz南轉之後,亞暴增長相或膨脹相期間,極光浪湧到達之前10—73min消失.相應的IMFBx>0,IMFBy<0.這種極光弧和亞暴極光不同,它們與地磁活動及Pi2脈動不相關.這7箇極光弧的形態和IMF特徵錶明,極光弧的增亮很可能由尾瓣重聯產生,很快衰減歸因于IMFBz南嚮條件,而黃昏方嚮運動受IMFBy控製.
이용남겁중산참겁광전천공섭상、지자、지자맥동수거화Wind위성적행성제자장IMF관측수거,분석료7개아폭기간고위황혼—자야선구겁광호적단잠증량현상.겁광호특정시,단잠증량수후흔쾌쇠감,력시10—20min,기본연착일-지방향,유명현황혼방향운동.저사사건대도발생재IMFBz남전지후,아폭증장상혹팽창상기간,겁광랑용도체지전10—73min소실.상응적IMFBx>0,IMFBy<0.저충겁광호화아폭겁광불동,타문여지자활동급Pi2맥동불상관.저7개겁광호적형태화IMF특정표명,겁광호적증량흔가능유미판중련산생,흔쾌쇠감귀인우IMFBz남향조건,이황혼방향운동수IMFBy공제.
Observations of all-sky auroral imaging, geomagnetic field, Pi2pulsation from Zhongshan Station and IMF data from Wind satellite have been used to investigate 7 cases of nightside auroral arcs intensification and f ading in high latitudes. The characteristics of auroral arcs are as follows: All of arcs intensify briefly, and then fade lasting for 10—20min; the arcs nearly align along the Sun-Earth direction with pronounced duskward drift; most of the arcs occur after the interplanetary magnetic field (IMF) turns southward corres ponding to the substorm growth or expansion phase, and IMF Bx>0, IMF B y<0; the dawn-dusk drift of the arcs is in the opposite direction of IMF By; these arcs have no close relation to magnetic activities and Pi2 p ulsation. The present results suggest that the brief intensification of auroral arcs may be due to IMF Bx>0 which favors magnetic reconnection in the sou thern lobe of the magnetotail, the arc fading may be attributed to southward IMF Bz, and the dawn-dusk motion of the arcs may be driven by the effect of the IMF By on the motion of the reconnection site.