The physical process in the Earth's polar region is very complex and still needs to be further studied.Using the data from Cluster satellite measurement,an analysis on field-aligned electrons in the mid-latitude c...The physical process in the Earth's polar region is very complex and still needs to be further studied.Using the data from Cluster satellite measurement,an analysis on field-aligned electrons in the mid-latitude cusp on 30 September 2001 has been performed.The satellite observed a down-flowing electron event in the low-latitude boundary and a sequential up-flowing electron event in the high-latitude boundary of the cusp region.The down-flowing electron had a velocity as high as 500 km/s and a flux of 2.0×10^(9) cm^(-2)-s^(-1).The up-flowing electron had a velocity up to 1200 km/s and a flux of 4.9×10^(9) cm^(-2)-s^(-1).Both the velocity and the flux observed in this event are the maximum values of the up-flowing electrons observed by all satellites to date.The electron is the main contributor for the field-aligned current in this event.The physical mechanism is also discussed.The down-flowing electron in the low-latitude boundary of the cusp region may result from solar wind injecting during the southward IMF,and the up-flowing electrons in the high-latitude boundary of cusp may result from mirroring of the solar wind,or from the ionospheric up-flowing electrons which have been accelerated.展开更多
A statistical study of the properties of ions (O+, He+ and H+) measured by the Cluster-II in cusp region as a function of the solar wind dynamic pressure and geomagnetic index Kp respectively was made dur-ing the summ...A statistical study of the properties of ions (O+, He+ and H+) measured by the Cluster-II in cusp region as a function of the solar wind dynamic pressure and geomagnetic index Kp respectively was made dur-ing the summer and fall of 2001-2003. The main results are that: (1) O+ ion density responds in a sig-nificant way to geomagnetic index Kp, and He+ ion density is not correlated with geomagnetic index Kp, both of them have a significant positive correlation with solar wind dynamic pressure; (2) H+ ion density is also observed to increase with solar wind dynamic pressure, and not correlated with geomagnetic index Kp.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 41074114,40804031 and 40921063the Specialized Research Fund for State Key Laboratory in China.
文摘The physical process in the Earth's polar region is very complex and still needs to be further studied.Using the data from Cluster satellite measurement,an analysis on field-aligned electrons in the mid-latitude cusp on 30 September 2001 has been performed.The satellite observed a down-flowing electron event in the low-latitude boundary and a sequential up-flowing electron event in the high-latitude boundary of the cusp region.The down-flowing electron had a velocity as high as 500 km/s and a flux of 2.0×10^(9) cm^(-2)-s^(-1).The up-flowing electron had a velocity up to 1200 km/s and a flux of 4.9×10^(9) cm^(-2)-s^(-1).Both the velocity and the flux observed in this event are the maximum values of the up-flowing electrons observed by all satellites to date.The electron is the main contributor for the field-aligned current in this event.The physical mechanism is also discussed.The down-flowing electron in the low-latitude boundary of the cusp region may result from solar wind injecting during the southward IMF,and the up-flowing electrons in the high-latitude boundary of cusp may result from mirroring of the solar wind,or from the ionospheric up-flowing electrons which have been accelerated.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 40621003, 40674091 and 40523006)the International Collaboration Research Team Program of the Chinese Academy of Sciences
文摘A statistical study of the properties of ions (O+, He+ and H+) measured by the Cluster-II in cusp region as a function of the solar wind dynamic pressure and geomagnetic index Kp respectively was made dur-ing the summer and fall of 2001-2003. The main results are that: (1) O+ ion density responds in a sig-nificant way to geomagnetic index Kp, and He+ ion density is not correlated with geomagnetic index Kp, both of them have a significant positive correlation with solar wind dynamic pressure; (2) H+ ion density is also observed to increase with solar wind dynamic pressure, and not correlated with geomagnetic index Kp.
