Sizes and relative geoeffectiveness of interplanetary coronal mass ejections and the preceding shock sheaths during intense storms in 1996-2005

作者：Zhang J^*; Poomvises W; Richardson I G

来源：Geophysical Research Letters, 2008, 35(2): L02109.

DOI：10.1029/2007GL032045

We present a statistical study of the sizes of interplanetary coronal mass ejections ( ICMEs) and the preceding shock sheath regions in near- Earth space. The 46 events studied are a subset of the events responsible for intense ( Dst <= - 100 nT) geomagnetic storms in 1996 2005 in which only a single ICME was responsible for generating the storm. We find that the durations and radial sizes of these ICMEs range from 8.0 to 62.0 hr and 0.08 to 0.63 AU, respectively, with average values of 30.6 hr and 0.37 AU. The sheath durations and radial sizes range from 2.6 to 24.5 hr and 0.03 to 0.31 AU, with average values of 10.6 hr and 0.13 AU. On average, the ICME radial size is 2.8 times that of the sheath. In terms of their relative geoeffectiveness, ICMEs contribute on average about 71% of the total energy input ( sheath + ICME) into the magnetosphere.

• 出版日期2008-1-30