海平面月平均气压场低频波的时空谱分析

SPACE-TIME SPECTRAL ANALYSIS OF LOW FRE-QUENCY WAVES IN MONTHLY MEAN SEA LEVEL PRESSURE FIELDS

摘要:

本文根据Hayashi提出的时空谱分析方法,对1951—1974年10—60°N的海平面月平均气压场格点资料进行分析,给出了瞬变低频波及其分量(纯东进波、纯西退波和驻波)的时空特性。分析了不同谐波、不同纬度上盛行的周期,并对主要周期的特性加以分析。最后,文章分析了南方涛动与北半球行星1波的关系。指出南方涛动对北半球星行星1波的影响主要表现为热带东传的低频波,北半球副热带也存在着涛动系统,造成准3年周期的低频驻波。

Abstract:

In this paper, the method of space-time spectral analysis proposed by Haya-shi has been used for the grid data of monthly mean sea level pressure from 10°N to 60°N in 1951-1974. The temporal and spatial behaviour of low freque-ncy transient waves as well as their components-traveling eastward, traveling westward and standing waves-has been obtained: The prevailing periods have been found for each harmonic wave at these latitudes, and their behaviour of propagation has been analyzed. Finally, the relation between the South Oscillation and the planetary wave, harmonic wavenumber 1, in Northern Hemisphere has been investigated. It can be seen that the effect of the South Oscillation on the planetary wave is charaterized by the tropical low frequency waves traveling eastward, and that there is an oscillation system at subtroptical latitudes in Northern Hemisphere, which causes the low frequency standing waves with a period of quasi-three years.