Effect of the background magnetic field inhomogeneity on generation processes of whistler‐mode chorus and broadband hiss‐like emissions

DOI Web Site Web Site 被引用文献29件 参考文献29件 オープンアクセス
  • Yuto Katoh
    Department of Geophysics Graduate School of Science, Tohoku University Miyagi Sendai Japan
  • Yoshiharu Omura
    Research Institute for Sustainable Humanosphere Kyoto University Uji Kyoto Japan

この論文をさがす

説明

<jats:p>By a series of self‐consistent electron hybrid code simulations, we study the effect of the background magnetic field inhomogeneity on the generation process of whistler‐mode chorus emissions. Chorus with rising tones are generated through nonlinear wave‐particle interactions occurring around the magnetic equator. The mirror force plays an important role in the nonlinear interactions, and the spatial inhomogeneity of the background magnetic field is a key parameter of the chorus generation process. We have conducted numerical experiments with different spatial inhomogeneities to understand properties of the chorus generation process. We assume the same initial condition of energetic electrons at the magnetic equator in all simulation runs. The simulation results reveal that the spectral characteristics of chorus significantly vary depending on the magnetic field inhomogeneity. Whistler‐mode emissions are generated and propagate away from the equator in all simulation runs, but distinct chorus elements with rising tones are only reproduced in the cases of small inhomogeneities. In the simulation that had the smallest inhomogeneity, we find excitation of broadband hiss‐like emission (BHE) whose amplitudes are comparable to discrete chorus elements found in other simulation runs. The BHE consists of many wave elements with rising tones nonlinearly triggered in the region close to the magnetic equator. We show that the small spatial inhomogeneity of the background magnetic field results in the small threshold amplitude for the nonlinear wave growth and allows the triggering process of rising tone elements to emerge easily in the equatorial region of the magnetosphere.</jats:p>

収録刊行物

被引用文献 (29)*注記

もっと見る

参考文献 (29)*注記

もっと見る

関連プロジェクト

もっと見る

詳細情報 詳細情報について

問題の指摘

ページトップへ