摘要
在文献[1]中,我们已从理论和数值模拟两个方面研究了用经验正交函数作基函数缩减气候数值模式自由度的可行性与有效性。用理论模型作数值试验的结果是令人满意的,应用于实际气候数值模拟,一个还需考虑的关键问题是大气外强迫等各种因子变化允许的范围内,对实际资料作EOF展开的稳定性问题。本文分别用1951—1984年500 hPa月平均高度距平场资料,1966—1975年500 hPa候平均高度距平场资料,1965—1978年夏季500 hPa逐日高度距平场资料作EOF展开,并提出了经验正交函数展开精度稳定性的判断方法,旨在证明实际资料EOF展开在大气外强迫等各种因子变化的允许范围内是稳定的,以便为我们用实际资料的经验正交函数作基函数建立一个合理的简化动力模型提供坚实的资料基础。
In this paper a new method is given to judge the stability of the EOF expanded precision. The results show that. 1,The expanded precision of summer (winter) anomaly geopotential height by using the EOFs of winter (summer) anomaly geopotential height is approximately equal to that of winter (summer) anomaly geopotential height by using the EOFs in winter (summer); 2,The differences among expanded precision of the anomaly geopotential height in the year and those in other years based on EOFs of the anomaly geopotential height in the correspondent year are small. It means that the expanded precision of the observed data based on the EOFs is stable in the range of the normal variability of external forcing. So it is feasible that a simplified model with the small number of the degrees of freedom can be gotten when the EOFs of the observed data are used as basis.
出处
《气象学报》
CSCD
北大核心
1992年第3期342-345,共4页
Acta Meteorologica Sinica
基金
国家教委高等学校博士点专项科研基金
