Probability of Field-Aligned Currents Observed by the Satellite Cluster in the Magnetotail  

作　　者：程征伟 史建魁 ZHANG Tie-Long 刘振兴 

机构地区：[1]State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100080 [2]Space Research Institute, Austrian Academy of Sciences, Graz, Austria [3]Graduate University of Chinese Academy of Sciences, Beijing 100049

出　　处：《Chinese Physics Letters》2007年第4期1125-1127,共3页中国物理快报（英文版）

基　　金：Supported by the National Natural Science Foundation of China under Grant Nos 40621003, 40674091 and 40374057, and the International Collaboration Research Team Programme of the Chinese Academy of Sciences.

摘　　要：Field-aligned current （FAC） density distribution at the plasma sheet boundary layers is statistically studied. The FAC is calculated by the so-called curlometer technique with the data from FGM onboard the four Cluster spacecraft in 2001. By calculation we obtain a large number of FAC samples. In the samples, most of calculated FAC densities were very small and around zero caused by some errors or noise. In order to get the real FAC density distribution in the magnetotail, we use a three-Gaussian distribution to fit the errors, then subtract the estimated error contribution from the full distribution and obtain the FAC density distribution. The result shows that the FAC occurrence versus its density has a distribution consisting of a Gauss/an distribution with an additional decreasing exponential distribution. The most probable value of the FAC density is 3.45 pT/km.Field-aligned current （FAC） density distribution at the plasma sheet boundary layers is statistically studied. The FAC is calculated by the so-called curlometer technique with the data from FGM onboard the four Cluster spacecraft in 2001. By calculation we obtain a large number of FAC samples. In the samples, most of calculated FAC densities were very small and around zero caused by some errors or noise. In order to get the real FAC density distribution in the magnetotail, we use a three-Gaussian distribution to fit the errors, then subtract the estimated error contribution from the full distribution and obtain the FAC density distribution. The result shows that the FAC occurrence versus its density has a distribution consisting of a Gauss/an distribution with an additional decreasing exponential distribution. The most probable value of the FAC density is 3.45 pT/km.

关 键 词：PLASMA SHEET BOUNDARY SUBSTORMS LAYER 

分 类 号：O46[理学—电子物理学]