副热带一热带太平洋密跃层水量交换年际变化的模拟研究

利用一个全球海洋环流模式在3组风应力资料的强迫下模拟分析了副热带太平洋向热带太平洋密跃层水量输送的年际变化特征及其和风应力的关系,并设计数值试验,研究了密跃层水量输送的变化机制.结果表明,副热带太平洋向赤道太平洋的密跃层水量输送具有显著的年际变化.在年际时间尺度上,南北太平洋西边界密跃层水量输送都起着补偿内部路径输送的...

Numerical study of interannual variations of the subtropical-tropical pycnocline mass exchange in the Pacific Ocean

Interannual variations of the subtropical-tropical pycnocline mass exchange in the Pacific Ocean and its mechanisms are investigated by using a global oceanic general circulation model forcing with three wind stress datasets. The results show that the subtropical-tropical pycnocline mass exchange in the Pacific Ocean varies significantly on interannual time scales, and the variation of the interior pycnocline transport is found to be anticorrelated to the boundary pycnocline transport and the former is generally compensated by the latter. Comparison between two hemispheres shows that the variabilities of boundary and interior transports of southern hemisphere are more pronounced than those of northern hemisphere, also the correlation coefficients and compensation rate between boundary and interior transports of southern hemisphere are larger than those of northern hemisphere, but the variability of the net transport of southern hemisphere is smaller than that of northern hemisphere. In both hemispheres, the counteracting tendency of the boundary and interior transports is primarily due to the propagation of baroclinic Rossby waves induced by the changes of the off-equatorial wind stress curl. The sensitive experiments show that the net pycnocline transports in both the northern and southern hemisphere are mainly attributed to the variability of near-equatorial zonal wind stress, whereas the effect of the propagation of baroclinic Rossby waves only plays a second role and could not results in such a compensation rate in each hemisphere.