北太平洋海表面高度(SSH)与风应力变化的关系

SEA SURFACE HEIGHT (SSH) CHANGE AND ITS RELATIONSHIP WITH WIND STRESS IN THE NORTH PACIFIC OCEAN

利用1958—2008年的北太平洋海表面高度和风应力资料,并与ENSO和PDO指数进行相关分析。结果发现,风应力及其经向分量主要通过季节振动影响海表面高度(SSH)的年周期变化,纬向风应力主要通过多年振动影响SSH的ENSO和PDO周期。纬向风应力和SSH均以黑潮延伸体主轴为界,两侧呈现出相反的升降趋势,SSH为北降南升,纬向风应力南降北升。风应力和SSH升降趋势相同,均表现为"上升—下降—上升"的变化特征。在地形变化剧烈、等深线南北分布的海区,西风增强会导致SSH升高,且西侧升高较为明显。北风增强将导致北太平洋西岸SSH升高,东岸SSH降低。

Correlation analysis between sea surface height, wind stress and index of ENSO and PDO for the period of 1958--2008 shows in the North Pacific Ocean, wind stress and its meridional component affect the annual cycle of SSH mainly through the seasonal vibration, and the zonal component affect the ENSO and PDO cycles of the SSH through years of vibration. Separated by the Kuroshio extension spindle, the zonal wind stress and SSH show different trends at the same side： SSH decreases at the north while increasing at the south, and the zonal wind stress decreases at the south while in- creasing at the north. Wind stress and SSH has the same trend： ＂increase--decrease--increase＂. The westerly enhanced the SSH rise in sea area where the topography is steep and isobaths distribute along the north-south direction, and the west side increased more significantly. The north wind enhancement led to SSH rise at the west coast of the North Pacific and drop at the east coast.