利用一个大洋环流模式LICOM, 通过1958～2001年风应力 (ERA40) 和热通量驱动下的两组模拟试验, 检验了二者在北太平洋年际和年代际变率形成中的作用。结果表明, 尽管在年际尺度上热带太平洋变率主要受风应力影响, 但合理考虑热通量异常的强迫作用能够显著改进模式对El Niño的模拟效果, 包括对El Niño周期非规则性的成功模拟; 北太平洋SST的年际和年代际异常主要受热通量异常的影响, 合理考虑热通量强迫的年代际变化能够改善模式对北太平洋年代际变率的模拟效果。在北太平洋海盆的不同区域, 导致SST变率异常的因子不同: 在加利福尼亚沿岸, 冬季平均海温的变率异常主要由热通量的异常决定; 在北太平洋中部, 温度趋势异常主要受热通量和水平平流的作用影响; 在黑潮及其延伸体区域, 对温度趋势异常起主导作用的是热通量和海洋非线性作用, 与此同时, 水平平流和扩散的作用亦不容忽视。
The roles of wind stress and surface heat flux in generating the Pacific interannual and interdecadal variability are examined by using two sets of simulations performed with LASG/IAP climate ocean model named LICOM. It is found that the interannual variability of SST in the tropical Pacific is mainly controlled by wind stress, however, the simulation of El Niño is improved significantly when surface heat flux is considered. The interannual variability of SST in the North Pacific is generated by the effect of surface heat flux, though it can be reproduced partly in a simulation without interannual variability of surface heat flux. Simulation without interdecadal variability of surface heat flux fails to reproduce the Pacific Decadal Oscillation (PDO) pattern, which confirms that the interdecadal variability of SST is governed by surface heat flux.To reveal the contributions of surface flux, horizontal advection, vertical advection and diffusion (including horizontal and vertical diffusion) to the variability of winter averaged upper ocean temperature in different areas, the upper ocean heat budget is examined by using the output of LICOM_HW run. It shows that SST is controlled by different mechanisms in different regions. The anomaly of temperature trend is determined by both net surface heat flux and horizontal advection in the central North Pacific. But in the coast off California, only the anomaly of net surface heat flux is found to be dominant. In the Kuroshio and Kuroshio Extension (KKE) region, the contributions of net surface heat flux and the oceanic nonlinearity effect are significant, but the contributions of horizontal advection and diffusion should not be neglected.