日本地球惑星科学連合2021年大会

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[E] 口頭発表

セッション記号 P (宇宙惑星科学) » P-EM 太陽地球系科学・宇宙電磁気学・宇宙環境

[P-EM12] Dynamics of the Inner Magnetospheric System

2021年6月5日(土) 15:30 〜 17:00 Ch.05 (Zoom会場05)

コンビーナ:桂華 邦裕(東京大学大学院理学系研究科地球惑星科学専攻)、三好 由純(名古屋大学宇宙地球環境研究所)、W Lauren Blum(University of Colorado Boulder)、Yuri Shprits(Helmholtz Centre Potsdam GFZ German Research Centre for Geosciences)、座長:桂華 邦裕(東京大学大学院理学系研究科地球惑星科学専攻)

16:30 〜 16:45

[PEM12-20] Parameterized Lifetime of Energetic Electrons due to Interactions with Chorus Waves

*Dedong Wang1、Yuri Shprits1,2,3 (1.Helmholtz Center Potsdam German Research Centre for Geosciences Potsdam、2.University of Potsdam、3.UCLA)

キーワード:radiation belt electrons, lifetime, chorus waves

Chorus waves can cause the loss of energetic electrons in the Earth's radiation belts and ring current via pitch-angle diffusion. We calculated the bounce-averaged quasi-linear diffusion coefficients to quantify these processes. In this study, using these diffusion coefficients, we parameterize the lifetime of the electrons with energy range from 1 keV to 2 MeV. In each magnetic local time (MLT), we calculate the lifetime for each energy and L-shell using two different methods. By applying polynomial fits, we parameterize the electron life time as a function of L-shell and electron kinetic energy in each MLT. we derive the lifetime parameterization as a function of geomagnetic activity (Kp index), L, magnetic local time (MLT) and energy of electrons. The parameterized electron lifetimes show a strong functional dependence on Kp, L-shell and electron energy. During the storm time, the lifetimes for higher energy (> 100 keV) electrons range from hours to days in the heart of the radiation belts. In contrast, the lifetimes for electrons with lower energy (< 100 keV) range from minutes to hours. This parameterization of electron lifetime is convenient for inclusion in simulations in the inner magnetosphere.