日环食大气内重力波的探测和研究  

Detection and study of the Atmospheric Internal Gravity Waves on the Annular Solar Eclipse

作　　者：谢金来[1] 杨训仁[1] 李启泰 

机构地区：[1]中国科学院声学研究所 [2]贵州省环境保护科学研究所

出　　处：《电波科学学报》1990年第1期32-37,共6页Chinese Journal of Radio Science

基　　金：国家自然科学基金

摘　　要：日食期间,月影以超声速移过地球大气而使局部大气冷却。Chimonas 和 Hines认为大空冷却的结果产生激波,诱发大气重力波。在电离层中可检测到 TID,在地面上可检测到大气压力变化。虽然电离层中这种重力波信号很弱,但仍可检测到。地面压力变化发生在日食附近地区,甚至离主食带相当远的地方也可以测到。本文报告了在中国首次直接观测日环食引起地面压力波的检测结果。1987年9月23日日环食期间,位于环食带的乌鲁木齐,太原,徐州,苏州及偏食带的北京和贵阳六个次声观测站用电容式微气压计在我国首次探测到日环食产生的声重力波,其周期为10—60分钟,振幅为7—20帕斯卡(峰—峰值)。动态谱分析的结果表明,各地的重力波周期都具有连续的谱分布,其主周期为40分钟。此外,各地还记录到出现时间不同而周期更长的波。本文对这些结果作了初步讨论。During solar eclipse,the shadow of moon moves through the earth atmosphere with supersonic speed.Chimonas & Hines deem that the shock waves produced by cooling of atmosphere will induce gravity waves,and both TIDs and atmospheric pr- essure changes can be detected in the ionosphere and on the ground respectively.Al- though the AGW signals from solar eclipse are usually quite weak,they can still be detected.The pressure changes on ground level occur near the region of eclipse,but can be detected even far beyond the path of eclipse.This article is the first one to re- port results of detecting pressure waves caused by solar eclipse in China. During the 23rd September 1987 annular eclipse of the sun,AGWs have been de- tected and recorded at infrasound observatories in Urumqi,Taiyuan,Xuzhou and Su- zhou,which are situated within the path of annular eclipse as well as in Beijing and Guiyang,which are situated beside this path.The signals are detected by microbaro- meters of condenser microphone type.After analysing the waveforms of the recorded signals numerically,the wave periods and wave amplitudes are determined to be wi- thin the ranges from 10 to 60 minutes and from 7 to 20 pascals(peak to peak)res- pectively.The results from dynamical spectral analyses show that,the spectral distri- bution of all the gravity wave periods from various observatories are continuous and possess a common main period of 40 minutes.Moreover,there are waves with even longer periods in different observatories,and their appearance time are quite different.

关 键 词：日环食 大气 重力波 探测 

分 类 号：P182.27[天文地球—天文学]