Empirical Model of the Lowest Cutoff Altitude of Global Hiss Near Magnetic Equator
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发表刊物:Journal of Geophysical Research: Space Physics
关键字:Plasmaspheric hiss, Lowest cutoff altitude, empirical model, Lower cutoff frequency
摘要:Van Allen Probe observations indicate that whistler‐mode hiss waves below 1 kHz are absorbed at low altitudes near magnetic equator. The lowest cutoff frequency of equatorial hiss is close to the gyrofrequency of hydrogen ions. The lowest cutoff altitude of global hiss is extracted when its occurrence rate is equal to 0.005
on the plane of altitude (L in RE) and magnetic local time (MLT). By fitting the lowest cutoff altitude of global hiss, we constructed the empirical model of the lowest cutoff altitude of equatorial hiss under geomagnetically quiet (AE < 200 nT) and active (AE ≥ 200 nT) conditions. The enhanced substorm activities reduce the lowest cutoff altitude of hiss waves on the dawnside (MLT ∼ 1–5 hr), whereas the lowest cutoff altitude of the dayside hiss is nearly fixed at ∼1.1 RE (MLT ∼ 6–20 hr). From the dayside to the nightside (MLT ∼ 0–6 hr and 20– 24 hr), the lowest cutoff altitude of equatorial hiss raises gradually from 1.1 RE to 1.4 RE.
合写作者:L. Yang,K. X. Chen, +++
第一作者:L. Y. Li
论文类型:期刊论文
卷号:129
是否译文:否
发表时间:2024-07-04
收录刊物:SCI
发布期刊链接:
https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024JA032886