Propagation Characteristics of Whistler-Mode Chorus during Geomagnetic Activities
ZHOU Qing-Hua1,2, HE Yi-Hua1, HE Zhao-Guo1, YANG Chang1
1School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004 2State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100190
Propagation Characteristics of Whistler-Mode Chorus during Geomagnetic Activities
ZHOU Qing-Hua1,2, HE Yi-Hua1, HE Zhao-Guo1, YANG Chang1
1School of Physics and Electronic Sciences, Changsha University of Science and Technology, Changsha 410004 2State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100190
摘要A recently introduced ray-tracing method is adopted to study the propagation characteristics of whistler-mode chorus during different geomagnetic activities by using a global core plasma density model. Numerical calculations show that chorus waves tend to settle on a preferable magnetic shell L in the vicinity of the plasmapause. During high geomagnetic activity, the plasmapause position moves inward close to the Earth and chorus trajectories move inward together with plasmapause. The trajectory move closer to the plasmapause asθ increases. Chorus wave with lower frequencies will reflect multiple times while chorus wave with higher frequencies reflect once at the plasmapause before settling on the vicinity of the plasmapause. The current results present a first detailed study on the propagation characteristics of chorus during geomagnetic activities, and may account for the observation that chorus tends to be present in the vicinity of the plasmapause.
Abstract：A recently introduced ray-tracing method is adopted to study the propagation characteristics of whistler-mode chorus during different geomagnetic activities by using a global core plasma density model. Numerical calculations show that chorus waves tend to settle on a preferable magnetic shell L in the vicinity of the plasmapause. During high geomagnetic activity, the plasmapause position moves inward close to the Earth and chorus trajectories move inward together with plasmapause. The trajectory move closer to the plasmapause asθ increases. Chorus wave with lower frequencies will reflect multiple times while chorus wave with higher frequencies reflect once at the plasmapause before settling on the vicinity of the plasmapause. The current results present a first detailed study on the propagation characteristics of chorus during geomagnetic activities, and may account for the observation that chorus tends to be present in the vicinity of the plasmapause.
[1] LeDocq M J, Gurnettt D A and Hospodarsky G B 1998 Geophys. Res. Lett. 25 4063 [2] Parrot M, Santolik O, Gurnett D et al 2004 Ann. Geophys. 22 2597 [3] Santolik O, Chum J, Parrot M et al 2006 J. Geophys. Res. 111 A10208 [4] Bortnik J, Thorne R M, Meredith N P et al 2007 Geophys. Res. Lett. 34 L15109 [5] Li X, Baker D N, Temerin M et al 2005 Space Weather 3 S04001 [6] Baker D N 2002 Science 297(5586) 1486 [7] Zong Q-G, Zhou X Z, Li X, Song P, Fu S Y, Baker D N, Pu Z Y, Fritz T A, Daly P, Balogh A and Re\'me H 2007 Geophys. Res. Lett. 34 L12105 [8] Zong Q-G, Wang Y F, Yang B, Fu S Y, Pu Z Y, Xie L and Fritz T A 2008 Sci. Chin. E 51 1 [9] Lu Q M, Wang L Q, Zhou Y and Wang S 2004 Chin. Phys. Lett. 21 129 [10] Wang D Y, Huang G L and Lu Q M 2004 Chin. Phys. Lett. 21 1997 [11] Li L, Cao J and Zhou G 2005 J. Geophys. Res. 110 A03203 [12] Xiao F L, Zheng H N and Wang S 2005 Chin. Phys. Lett. 22 1552 [13] Xiao F L, Zheng H N and Wang S 2005 Chin. Phys. Lett. 22 517 [14] Xiao F L, Su Z P, Zheng H N and Wang S 2009 J. Geophys. Res. 114 A03201 [15] Zheng H N, Su Z P and Xiong M 2008 Chin. Phys. Lett. 25 3515 [16] Su Z P and Zheng H N 2008 Chin. Phys. Lett. 25 4493 [17] Su Z P, Zheng H N and Xiong M 2009 Chin. Phys. Lett. 26 039401 [18] Platino M, Inan U S, Bell T F et al 2005 J. Geophys. Res. 110 A03212 [19] Xiao F L, Chen L J, Zheng H N and Wang S 2007 J. Geophys. Res. 112 A10214 [20] Horne R B 1989 J. Geophys. Res. 94 8895 [21] Xiao F L, Chen L J, Zheng H N and Wang S 2008 Chin. Phys. Lett. 25 340 [22] Suchy K 1981 Radio Sci. 16 1179 [23] Gallagher D L, Craven P D and Comfort R H 2000 J. Geophys. Res. 105 18819 [24] Carpenter D L and Anderson R R 1992 J. Geophys. Res. 97 1097 [25] Chappell C R 1972 Rev. Geophys. 10 951 [26] Bortnik J, Inan U S and Bell T F 2003 J. Geophys. Res. 108(A5) 1199 [27] Masson A, InanU S, Laakso H et al 2004 Ann. Geophys. 22 2565 [28] Gao H N, Fa P T 2008 Chin. Phys. Lett. 25 2562 [29] Xiao F L, Zong Q G and Chen L X 2009 J. Geophys. Res. 114 A01215
2010, Vol. 27 
