CAJ | 학술논문

在黑潮入侵南海强弱的问题上，到底是太平洋年代际变化（Pacific Decadal Oscillation，PDO）还是厄尔尼诺-南方涛动（El Nio-Southern Oscillation，ENSO）现象在起关键作用，目前还存在着较大争议。本文先以高盐水作为黑潮入侵强弱的示踪物，用120°E 断面的高盐水数据和北赤道流分叉点（North Equator Current Bifurcation，NEC-Y）的南北变动进行相关分析，接着，进一步用学者所用的黑潮入侵指数（KI 指数，Kuroshio intrusion index 和 NEC 指数，North Equatorial Current index）与北赤道流分叉点南北变动进行相关分析。最后，用 EMD（Empirical Mode Decomposition）方法和相关关系分析法分别分析了 PDO 指数、Nio3．4指数与北赤道流分叉点南北变动的关系并用 NECP 风场数据探讨其影响机制。结果表明：（1）通过对120°E 断面的高盐水的 KI 指数、NEC 指数与 NEC-Y 的相关分析，表明了北赤道流分叉点的南北变动能够很好地指代黑潮入侵南海的强弱；（2）通过 PDO 指数和Nio3．4指数与北赤道流分叉点的南北变动的相关性分析，发现 PDO 指数、Nio3．4指数与北赤道流分叉点的南北变动都具有较好的相关性，都在0．5水平。这些良好的相关性表明了 PDO 和 ENSO 对黑潮入侵南海的强弱都具有重要的影响；（3）当处于厄尔尼诺年（拉尼娜）时，赤道太平洋发生西（东）风异常，使得北赤道流分叉点偏北（南），使吕宋岛东侧的黑潮流速减弱（加强），黑潮入侵南海增强（减弱）；当 PDO 处于暖（冷）阶段时，会加强热带太平洋的西（东）风异常，使得黑潮入侵南海增强（减弱）。
재흑조입침남해강약적문제상，도저시태평양년대제변화（Pacific Decadal Oscillation，PDO）환시액이니낙-남방도동（El Nio-Southern Oscillation，ENSO）현상재기관건작용，목전환존재착교대쟁의。본문선이고염수작위흑조입침강약적시종물，용120°E 단면적고염수수거화북적도류분차점（North Equator Current Bifurcation，NEC-Y）적남북변동진행상관분석，접착，진일보용학자소용적흑조입침지수（KI 지수，Kuroshio intrusion index 화 NEC 지수，North Equatorial Current index）여북적도류분차점남북변동진행상관분석。최후，용 EMD（Empirical Mode Decomposition）방법화상관관계분석법분별분석료 PDO 지수、Nio3．4지수여북적도류분차점남북변동적관계병용 NECP 풍장수거탐토기영향궤제。결과표명：（1）통과대120°E 단면적고염수적 KI 지수、NEC 지수여 NEC-Y 적상관분석，표명료북적도류분차점적남북변동능구흔호지지대흑조입침남해적강약；（2）통과 PDO 지수화Nio3．4지수여북적도류분차점적남북변동적상관성분석，발현 PDO 지수、Nio3．4지수여북적도류분차점적남북변동도구유교호적상관성，도재0．5수평。저사량호적상관성표명료 PDO 화 ENSO 대흑조입침남해적강약도구유중요적영향；（3）당처우액이니낙년（랍니나）시，적도태평양발생서（동）풍이상，사득북적도류분차점편북（남），사려송도동측적흑조류속감약（가강），흑조입침남해증강（감약）；당 PDO 처우난（랭）계단시，회가강열대태평양적서（동）풍이상，사득흑조입침남해증강（감약）。
There is a controversy about the role of Pacific Decadal Oscillation (PDO)and El Nio-Southern Oscilla-tion (ENSO)in the Kuroshio intrusion into the South China Sea. In this study,we firstly analyzed the correlation of the subsurface high salinity water in the 120°E section and the North Equatorial Current Bifurcation(NEC-Y). Secondly,we analyzed the relation of Kuroshio intrusion index(KI index),North Equatorial Current index(NEC index)and the North Equatorial Current Bifurcation. Finally,we analyzed the pertinence of PDO index,Nio 3.4 index and the North Equatorial Current bifurcation by methods of EMD and correlation coefficient and analyzed the mechanism by NECP wind data. The result shows:(1)the NEC-Y has a well correlation with subsurface high sa-linity water in the 120°E section,the KI index and the NEC index. So the NEC-Y can been a good index of the strength of Kuroshio intrusion into the South China Sea;(2)there is a well 0.5 level of correlation coefficients be-tween NEC-Y and the PDO index ,the Nio 3.4 index. These well correlated coefficients show that both PDO and ENSO have important effect on the strength of Kuroshio intrusion into the South China Sea;(3)in El Nio (La Nia)year,a western (eastern)anomalous wind of the tropical Pacific causes a northward (southward)shift of the North Equatorial Current Bifurcation Latitude. This results in a weakened (enhanced)Kuroshio off Luzon,favor-ing Kuroshio intrusion into the South China Sea..While PDO is in the warm (cold)phase,the western (easern)a-nomalous wind will be strenghened in tropical Pacific and this will cause a northward(southward)shift of the North Equatorial Current Bifurcation Latitude too. So,the strength of Kuroshio intrusion into the South China Sea will be enhanced (weakened).