CAJ | 학술논문

经验正交函数分解（EOF）是气候特征研究中常用的分析方法，但由于方法本身的原因，EOF 主要模态不一定都能有效揭示资料场包含的气候模态。利用中国基本站和基准站1950—2009年逐日降水资料，运用显著经验正交函数分解（Disˉ tinct EOF，DEOF）方法研究了淮河流域暴雨的统计特征。结果表明 DEOF 第1模态呈现了淮河流域暴雨量在南北方向上存在相反的变化，即流域中部、南部偏多（偏少）时，北部则偏少（偏多），第1主成分具有显著的16—17 a 周期性变化，表明流域南北的旱涝变化存在年代际振荡；第2模态表现了淮河流域中部暴雨量的异常变化，第2主成分有明显的线性趋势，说明近50年来流域中部地区暴雨量有明显的上升趋势，并且在1990年前后由偏少转为偏多。对比 DEOF 和 EOF 的分析结果，发现DEOF 能排除资料场中与随机扩散模型相关性较高的空间特征，能抓住与随机扩散模型有显著差异的分布特征并凸出显示出来，能从较强的背景噪声中凸出物理信号，因而能更好地估计真实的气候模态。
경험정교함수분해（EOF）시기후특정연구중상용적분석방법，단유우방법본신적원인，EOF 주요모태불일정도능유효게시자료장포함적기후모태。이용중국기본참화기준참1950—2009년축일강수자료，운용현저경험정교함수분해（Disˉ tinct EOF，DEOF）방법연구료회하류역폭우적통계특정。결과표명 DEOF 제1모태정현료회하류역폭우량재남북방향상존재상반적변화，즉류역중부、남부편다（편소）시，북부칙편소（편다），제1주성분구유현저적16—17 a 주기성변화，표명류역남북적한로변화존재년대제진탕；제2모태표현료회하류역중부폭우량적이상변화，제2주성분유명현적선성추세，설명근50년래류역중부지구폭우량유명현적상승추세，병차재1990년전후유편소전위편다。대비 DEOF 화 EOF 적분석결과，발현DEOF 능배제자료장중여수궤확산모형상관성교고적공간특정，능조주여수궤확산모형유현저차이적분포특정병철출현시출래，능종교강적배경조성중철출물리신호，인이능경호지고계진실적기후모태。
The empirical orthogonal function (EOF)is a commonly analytical tool in climate study.But because of the constraints of the method itself,not all the leading EOF modes can reveal the true climate mode from the climatological data in some cases.Based on the daily precipitation datasets from the basic stations over the Huaihe River Basin from 1961 to 2009,the climatological statistical characteristics of the rainstorms in the Huaihe River Basin are studied by using the Distinct EOF (DEOF)method.The results show that DEOFˉ1 displays contrary changes in the south-north direction on the rainstorm precipitation in the Huaihe River Basin,which means that when the rainstorm precipitation of the central and southern region is more (less)than normal state,the northern region is less (more)than normal state.The first principal component has obvious periodic oscillations of 16 -17 years,suggesting that the drought and flood in southern and northern region show a decadal oscillation;DEOFˉ2 displays the abnormal changes of the rainstorms in the central region of the Huaihe River Basin,and the second principal component has a obvious linear trend showing a upward trend in the last 50 years and a convertion from less to more than normal at about 1990.Comparing with the EOF analysis,DEOF can effecˉ tively exclude the spatial characteristics related hiqhly to the stochastic diffusion model,catch the features having significant differences with the model and display the features more prominently,and detect physical signals from a strong background noise,and therefore it should be a better estimate for the true climatic mode.