Synthetic Seismogram for the Velocity and Attenuation Structure Near the Inner-Outer Core Boundary Using the Generalized Ray Method

以廣義射線法合成地震圖推求內外核界面處之速度與震波衰減構造

黃柏壽(Bor-Shouh Huang) ； 姚振興(Zhen-Xing Yao) ； 葉永田(Yeong Tein Yeh)

《Terrestrial, Atmospheric and Oceanic Sciences》 9卷2期 (1998/06) Pp. 287-300

並列摘要

We present the analysis of plasma and field data acquired from theAMPTE/IRM satellite for ULF wave fluctuations in the subsolarmagnetosheath under a”quiet”condition.A total of seven magnetosheathcrossings,representing twelve hours of observations,were selected for statisticalanalysis.The statistical analysis results indicated that mirror-likecompressional fluctuations are typical of the quiet-state subsolarmagnetosheath.It is also found that mirror-like fluctuations with typicalfrequencies between 10mHz and 80mHz(or 0.02f(subscript H)+≤f≤0.2f(subscript H)+,wheref is the wave frequency and f(subscript H)+the local proton gyro frequency)are associatedwith 0.1≤(T(subscript ⊥)/T(subscript Ⅱ)-1)≤0.6 and 1≤β(subscript p)≤10 magnetopause plasma,where β(subscript p)is the proton beta and T(subscript ⊥)and T(subscript Ⅱ)are the perpendicular andparallel proton temperature,respectively.We also found that the conditionfor mirror instability,T(subscript ⊥)/T(subscript Ⅱ)＞1+β^(-1)(subscript ⊥),is generally not satisfied in the entireregion of the magnetosheath,especially near the magnetopause.Thismay indicate that temperature anisotropy is reduced due to the developmentof mirror waves as suggested by Price et al.[1986]and Lee et al.[1988].

並列關鍵字

Generalized Ray Method ； Synthetic Seismogram ； Inner-Core Boundary ； Attenuation