Near-Earth bursty bulk flows and AE index  

作　　者：W BAUMJOHANN M. W. DUNLOP C. CARR H. RME 

机构地区：[1]Space Research Institute, Austrian Academy of Sciences, Graz, Austria [2]Space Sciences Division, Rutherford Appleton Laboratory, Chilton, Didcot, UK [3]Imperial College, London, United Kingdom [4]Centre d'Etude Spatiale des Rayonnements, Toulouse, France

出　　处：《Science China(Technological Sciences)》2008年第10期1704-1712,共9页中国科学（技术科学英文版）

基　　金：the National Natural Science Foundation of China (Grant Nos. 40704031, 40674091 and 40536030)

摘　　要：With the 4-s resolution data of the magnetometer and the ion plasma analyzer on TC-1 from June to November of each year during the period of 2004―2006, we statistically analyzed the occurrence rate of both convective and field-aligned bursty flows (FABFs). A near-Earth bursty bulk flow (NEBBF) occurred during both the quiet time and substorm process. In general, the magnetic field and the plasma density began oscillating with the appearance of the NEBBF associated with a distinct increase of the AE index. The increase of AE index during the NEBBF was more than 100 nT in both quiet time and substorm process. The statistical analysis indicated that the occurrence rates of the FABFs were nearly the same in the dif-ferent stages of the AE index, but the occurrence rate of the NEBBFs was much higher in the growth stage of the AE index, indicating that the NEBBFs were di-rectly related to the growth and expansion phases of the substorm. The observa-tions suggested that the quite large number of BBFs from the mid magnetotail could enter into the near-Earth tail and play important role in triggering the sub-storm onset.With the 4-s resolution data of the magnetometer and the ion plasma analyzer on TC-1 from June to November of each year during the period of 2004-2006, we statistically analyzed the occurrence rate of both convective and field-aligned bursty flows (FABFs). A near-Earth bursty bulk flow (NEBBF) occurred during both the quiet time and substorm process. In general, the magnetic field and the plasma density began oscillating with the appearance of the NEBBF associated with a distinct increase of the AE index. The increase of AE index during the NEBBF was more than 100 nT in both quiet time and substorm process. The statistical analysis indicated that the occurrence rates of the FABFs were nearly the same in the different stages of the AE index, but the occurrence rate of the NEBBFs was much higher in the growth stage of the AE index, indicating that the NEBBFs were directly related to the growth and expansion phases of the substorm. The observations suggested that the quite large number of BBFs from the mid magnetotail could enter into the near-Earth tail and play important role in triggering the substorm onset.

关 键 词：BBF near-Earth AE INDEX SUBSTORM ONSET 

分 类 号：P353[天文地球—空间物理学]