西-亚北极锋季节及年际特征分析

Analysis on seasonal and interannual variations of the Western Subarctic Front

基于1982-2016年的OISST资料分析了西-亚北极锋(The Western Subarctic front,WSAF;37°N-45°N,146°E-152°E)强度与位置的季节及年际变化特征,结果表明:冬季WSAF强度最大,平均位置最靠南;夏季WSAF强度最小,平均位置最靠北;春秋两季WSAF强度、平均位置相当,位于冬夏之间;1982-2016年,WSAF强度逐渐增强,分布位置逐渐缓慢南移;各季节WSAF强度最大值稳定位于149°E附近,WSAF平均位置自西向东不断北移。在此基础上,分析了不同季节WSAF强度与黑潮-亲潮交汇区(The Kuroshio-Oyashio Confluence Region,KOCR)内水体性质的关系:KOCR内黑潮水特征显著时WSAF强度小,黑潮水特征不显著时WSAF强度大;利用EOF分析探寻了WSAF强度年际变化与KOCR内海温的关系:不同季节内WSAF年际变化与KOCR内海温相关性不显著,春、夏、秋季,随着KOCR内海温升高,WSAF强度减弱,而冬季WSAF强度随KOCR内海温升高而增强。

Based on the OISST data during 1982-2016,the seasonal characteristics of the Western Subarctic Front(WSAF;37°N-45°N,146°E-152°E)intensity and position are analyzed:WSAF intensity reaches the strongest in winter,the average position is southernmost;while the weakest appears in summer,the average position is northernmost;WSAF intensity are similar in spring and autumn;the WSAF intensity increase gradually,WSAF average position move southerly slowly during 1982 to 2016;the maximum of WSAF intensity is stable near 149°E each season,while the average position move northerly from west to east.On this basis,the relation between the WSAF intensity and the water properties in the Kuroshio-Oyashio Confluence Region(KOCR)is analyzed:WSAF intensity is weak when characteristics of Kuroshio is significant in KOCR;it is strong when characteristics of Kuroshio is not significant in KOCR.The relationship between the interannual variation of WSAF intensity and SST in KOCR is explored by EOF analysis.The interannual variation of WSAF intensity in different sea-sons is not significantly correlated with seawater temperature in KOCR.In spring,summer and autumn,with the growth of seawater temperature in KOCR,the intensity of WSAF decrease,while in winter,the intensity of WSAF increase with the growth of seawater temperature in KOCR.