风应力输入到海洋中的能量的气候变率特征

利用麻省理工学院海洋环流模式研究了风应力输入到海洋中的能量的气候变率特征。结果表明:风应力输入到海洋中的能量对气候变化有显著的响应。在北大西洋涛动(North Atlantic Oscillation,NAO)正位相的年份,风应力输入到海洋中的能量的大值区北移且加强,主要由于暴风路径的北移和天气尺度大气扰动的加强导致;同样,在南半球环状模(Southern Annular Mode,SAM)正位相年份输入到南大洋的能量大值区南移并加强,且输入到南极大陆沿岸流中的能量也有显著增加。经验正交函数分解分析结果表明:NAO主导了风应力输入到北大西洋区域的能量变化。SAM解释了南大洋区域风应力输入能量的第一模态,第二、三模态解释了受ENSO(El Niňo-Southern Oscillation)影响的情况。最近几十年,在南大洋区域,风应力及其输入能量的年代际变化都有所增强,而在北半球的中高纬度区域有所下降。

Climate variability characteristics of wind power input to the world oceans

In this study,the interannual variability of wind power input(WPI) is investigated by MITgcm.The response of WPI to climate change is also analyzed.The result of the simulation indicates that the responses of the WPI to the world ocean to the climate change signifycantly.The areas of high value of time-mean WPI to the ocean are located in the middle and high latitude regions,such as the South China Sea,Kuroshio Current and Gulf Stream,due to the fact that the synoptic scale disturbance of atmosphere is significant in these areas.Moreover,the areas of high decadal variability of the WPI to the ocean are located in the South China Sea and Storm Tracks.The value of max WPI increases and the area of max WPI shifts northward in the North Atlantic,resulting from the strengthening and northward-shifting Storm Tracks in the positive phase of North Atlantic Oscillation(NAO).However,there is a greater amount of WPI that travels into the Gulf Stream when the phase of NAO is negative.The WPI to the South China Sea has been increasing with the increasing intensity of Westerlies in the recent decades,and the area of max WPI has shifted southward as the Westerlies shift southward in the Southern Hemisphere.Similarly,the WPI to the Antarctic coastal current increases significantly during this period.The Empirical Orthogonal Function(EOF) analysis shows that the variability of the WPI to the North Atlantic Ocean is dominated by the NAO,while the second and third modes indicate the distributions of the WPI to the oceans during positive phase or negative phase of the NAO.The Southern Annual Mode (SAM) leads to the first EOF mode in the South China Sea,while the second and third modes are related to the El Niño-Southern Oscillation (ENSO).The decadal variability of the WPI to the South China Sea has been increasing significantly in recent decades,while it has decreased in middle and high latitudes in the northern hemisphere.