Quasi-linear modeling of gyroresonance between different MLT chorus and geostationary orbit electrons  

作　　者：ZHANG ZeLong XIAO FuLiang HE YiHua HE ZhaoGuo YANG Chang ZHOU XiaoPing TANG LiJun 

机构地区：[1]School of Physics and Electronic Sciences,Changsha University of Science and Technology,Changsha 410004,China [2]Key Laboratory of Basic Plasma Physics,Chinese Academy of Sciences,Here China,230026

出　　处：《Science China(Information Sciences)》2012年第11期2624-2634,共11页中国科学（信息科学）（英文版）

基　　金：supported by National Natural Science Foundation of China (Grant No. 41274165);Aid Programfor Science and Technology Innovative Research Team in Higher Educational Institutions of Hunan Province;Construct Program of the Key Discipline in Hunan Province;Open Research Program from Key Laboratory of Basic Plasma Physics,Chinese Academy of Sciences

摘　　要：The contributions of dayside and nightside gyroresonance of chorus waves to electron radiation belt evolution at L = 6.6 are detailedly differentiated via fully solving the two-dimensional Fokker-Plank equation. The numerical results show that the chorus waves at different regions play significantly different roles. The dayside chorus waves can cause obvious loss of energetic electrons at lower pitch angles and weak energization at larger pitch angles. The nightside chorus waves can yield significant energization at larger pitch angles, but cannot efficiently resonate with the energetic electrons at lower pitch angle. Due to the numerical difficulty in fully solving Fokker-Planck equation, the cross diffusion terms are often ignored in the previous work. Here the effect of cross diffusion at different regions is further analyzed. On the dayside, ignoring cross diffusion overestimates the electron phase space density by several orders of magnitude at lower pitch angles, and con- sequently the dayside chorus waves are incorrectly regarded as an effective energization mechanism. On the nightside, ignoring cross diffusion overestimates the electron phase space density （PSD） by about one order of magnitude at larger pitch angles. These numerical results suggest that cross diffusion terms can significantly affect gyroresonance of chorus waves on both the dayside and nightside, which should be included in the future radiation belt models.The contributions of dayside and nightside gyroresonance of chorus waves to electron radiation belt evolution at L = 6.6 are detailedly differentiated via fully solving the two-dimensional Fokker-Plank equation. The numerical results show that the chorus waves at different regions play significantly different roles. The dayside chorus waves can cause obvious loss of energetic electrons at lower pitch angles and weak energization at larger pitch angles. The nightside chorus waves can yield significant energization at larger pitch angles, but cannot efficiently resonate with the energetic electrons at lower pitch angle. Due to the numerical difficulty in fully solving Fokker-Planck equation, the cross diffusion terms are often ignored in the previous work. Here the effect of cross diffusion at different regions is further analyzed. On the dayside, ignoring cross diffusion overestimates the electron phase space density by several orders of magnitude at lower pitch angles, and con- sequently the dayside chorus waves are incorrectly regarded as an effective energization mechanism. On the nightside, ignoring cross diffusion overestimates the electron phase space density （PSD） by about one order of magnitude at larger pitch angles. These numerical results suggest that cross diffusion terms can significantly affect gyroresonance of chorus waves on both the dayside and nightside, which should be included in the future radiation belt models.

关 键 词：geostationary orbit chorus waves wave-particle interaction 

分 类 号：V474.21[航空宇航科学与技术—飞行器设计] P182.52[天文地球—天文学]