CAJ | 학술논문

用功率谱分析、小波分析和经验正交函数(EOF)分析三种方法,对比分析了1953～2002年北京单站以及中国区域地表气温的传统距平与以集合经验模分解(EEMD)的频-幅调制年循环(MAC)为参照的"距平",同时还比较了用传统距平描述的"年际及更长尺度变率"和以MAC为参照的年以上尺度低频分量.通过对比分析,发现传统距平和用传统距平所描述的"年际及更长尺度变率"仍然包含有年周期,而且还包含有小于年尺度的波动;而去除MAC的距平则更好地去除了准年周期,而且以MAC为参照的年以上尺度低频分量只包含有1年以上尺度的波动,因而更适合用来描述"年际及更长尺度变率".
용공솔보분석、소파분석화경험정교함수(EOF)분석삼충방법,대비분석료1953～2002년북경단참이급중국구역지표기온적전통거평여이집합경험모분해(EEMD)적빈-폭조제년순배(MAC)위삼조적"거평",동시환비교료용전통거평묘술적"년제급경장척도변솔"화이MAC위삼조적년이상척도저빈분량.통과대비분석,발현전통거평화용전통거평소묘술적"년제급경장척도변솔"잉연포함유년주기,이차환포함유소우년척도적파동;이거제MAC적거평칙경호지거제료준년주기,이차이MAC위삼조적년이상척도저빈분량지포함유1년이상척도적파동,인이경괄합용래묘술"년제급경장척도변솔".
Traditional anomaly of surface air temperature was compared with "anomaly" in amplitude-frequency modulated annual cycle (MAC) reference frame defined by the Ensemble Empirical Mode Decomposition (EEMD) method using power spectrum analysis, wavelet analysis, and Empirical Orthogonal Function (EOF) analysis for Beijing station and all over China during the period from 1953 to 2002. The "interannual and longer timescale variability" represented by the traditional anomaly was also compared with the low frequency (timescale is longer than one year) component in MAC reference frame. The results show that the traditional anomaly and the traditional "interannual and longer timescale variability" still contain residual annual cycle. Moreover, the fluctuations with timescale less than one year exist in the traditional anomaly. In contrast, the anomaly that the MAC is excluded better excluded annual cycle, and the low frequency component in MAC reference frame only contains fluctuations with timescale longer than one year, thus it is more suitable to represent "interannual and longer timescale variability".