海洋的季节变化及风应力异常对海洋影响的数值试验

对一个6层5°×4°网格的全球海洋模式作了一些改进,建立了10层5°×4°网格的全球海洋模式,进行了季节变化数值模拟,积分250a,取得稳定的结果.除了高纬度海洋外,模拟的季节变化与实际观测十分接近.在此基础上,作了热带太平洋海温场对热带季风异常响应的3组敏感性实验,第1组为赤道西太平洋异常西风向东传播的试验;第2组为整个赤道太平洋风应力振荡异常试验;第3组为赤道西太平洋异常西风、东风交替向东传播的敏感性试验.模拟结果表明:(1)第1组风应力敏感性实验结果揭示出,西太平洋西风异常的向东传播的风应力异常可以产生类似厄尔尼诺的赤道东太平洋变暖;(2)第2组试验结果表明,热带太平洋风应力的局地振荡首先在中太平洋东西部激发出海温扰动,然后海温扰动分别向东太平洋和西太平洋传播,从而引起东、西太平洋海温的异常;(3)第3组试验验证风应力QBO可以产生海洋中类似的QBO振荡.

Numerical simulation of global ocean seasonal variation and impact of anomaly of windstress on sea temperature

By improving a six-layer global ocean model with a resolution of 5°×4°, we have established a ten-layer global ocean model with the same resolution and simulated the seasonal variation of global ocean.After a 250 year integration, an equilibrium state of ocean was reached.The simulated seasonal variation is similar to that of observed except for ocean in high latitude.Then we took the results at the end of seasonal variation as the initial state for a series of sensitive experiments.On the basis of these work mentioned above, we have done three kinds of windstress anomaly sensitive experiments on the response of sea temperature in tropical Pacific to anomaly of tropical monsoon.First kind of sensitive experiment is involved in anomalous westerly propagating eastwards over equatorial western Pacific; second is an experiment on anomaly of windstress oscillation over the whole equatorial Pacific, and third experiment is made on alternating between anomalous westerly propagating eastwards and anomalous easterly propagating eastwards over equatorial western Pacific.The simulation results of three kinds of sensitive experiments show as follows.(a) Sea temperature's warming in eastern Pacific similar to El Niño event can be reproduced by westerly windstress anomaly propagating eastwards in western Pacific in first kind of windstress anomaly sensitive experiment.(b) In second kind of experiment, sea temperature anomaly was first stimulated in east and west part of tentral Pacific respectively by local oscillation of windstress in tropical Pacific, then propagated eastwards and westwards to eastern Pacific and western Pacific respectively.As a result sea temperature anomaly emerged at equatorial eastern Pacific and western Pacific.(c) The third kind of experiment have shown that QBO of windstress can motivate oscillation of ocean similar to QBO.