北太平洋风场变化对东亚陆架海SST的影响

Pacific Wind Change and Its Influence on SST in East Asia Marginal Sea

太平洋内部的气候变化与东亚陆架海海洋环境变化密切相关。本文利用OAflux资料、NCEP再分析资料,分析北太平洋内部风场的时空变化特征,将其距平场序列与东亚陆架海SSTA序列进行相关性分析,找出对东亚陆架海SST影响显著的风场关键区。结果表明:东亚陆架海SST距平序列与PDO指数同期相关系数接近于0,说明北太平洋内部异常信号只能通过斜压Rossby波调整影响东亚陆架海SST,不存在正压调整过程;北太平洋风场"关键区A、B"对东亚陆架海SST的变化影响最显著,且1958—2010年,2个风场"关键区"风速异常增强,分别被风应力旋度偶极子、异常负风应力旋度场控制,异常信号从中东太平洋传递到东亚陆架海,导致该海区SST明显升高,尤其是黑潮海域;"关键区A、B"风场异常信号分别超前东亚陆架海SST变化4a(7a)、4a时呈显著正相关,该时间基本与斜压Rossby波从大洋中东部传递到西部或副热带环流对风场变化通过斜压Rossby波进行调整所需的时间一致。

Pacific internal climate change is closely related to changes of the marine environment in East Asia marginal sea.OAflux and NCEP reanalysis data were used to study the wind spatial and temporal variation within the North Pacific.Correlation analyses between the wind speed anomalies in North Pacific and the times series of SST anomaly in East Asia marginal sea were made to find out the wind key region influencing on East Asia marginal sea signally.The results showed that,correlation coefficient between the SSTA in East Asia marginal sea and the PDO index with a zero-lag is close to 0,which showed that abnormal signals within North Pacific affected SST in East Asia marginal sea only by baroclinic Rossby waves adjustments,not the barotropic change.The wind key region A and B over North Pacific influenced on East Asia marginal sea signally,and during 1958—2010,wind speed in the two key regions increased abnormally,meanwhile,they were controlled by the curl dipole,abnormal negative wind stress curl separately,so the abnormal signals propagated from the Middle and East Pacific to East Asia marginal sea,causing SST increased significantly,especially in the Kuroshio.Wind variations over the key region A,B leaded SST changes in East Asia marginal sea by 4a（7a）,4a separately,which were in consistent with the time needed of Rossby waves propagating from the middle,east ocean to the west or subtropical circulation adjustment by Rossby waves.