【作者】 张洪海；

【导师】 吴立新；

【作者基本信息】 中国海洋大学 ， 物理海洋学， 2010， 硕士

【摘要】 本文利用一阶线性斜压Rossby波模型研究了北大西洋海表温度(SST)低频变异的可预测性。研究发现,在5°N到20°N之间的北大西洋热带海域、27°N到34°N之间的北大西洋副热带东部海域以及纽芬兰岛东部海域,一阶线性斜压Rossby波模型可以解释冬季SST年际-年代际变异方差的10%～46%。在北大西洋热带和副热带-中纬度海区,风强迫激发的斜压Rossby波可以通过不同的物理机制影响SST的变化。在热带区域,由向西传播的斜压Rossby波产生的温跃层异常主要通过持续稳定的上升流到达海洋表层进而影响SST；而在副热带和中纬度海区,冬季海洋上混合层内的垂向对流混合、卷挟(entrainment)过程是连接西传Rossby波产生的温跃层异常和SST异常的最主要物理过程。研究还发现,基于一阶线性斜压Rossby波模型,冬季SST异常在热带北大西洋、副热带北大西洋和纽芬兰东部海域的有效预报时间尺度分别为三个月、十八个月和三年。利用NCEP-NCAR的风应力再分析资料,本研究预报了上述海域SST的低频变异。更多还原

【Abstract】 Predictability of sea surface temperature (SST) variations over the North Atlantic Ocean is studied based on the first-mode baroclinic Rossby wave model. This simple linear wave model can explain about 10%-46% of the wintertime SST variability in several regions of the North Atlantic basin, including the tropics between 5°N and 20°N, the eastern subtropics between 27°N and 34°N, and the east of Newfoundland.The wind-forced baroclinic Rossby waves can affect SST through different mechanisms in the tropics and subtropical-midlatitude North Atlantic. In the tropics, thermocline anomalies generated by the westward propagating Rossby waves affect SST predominantly through mean upwelling, but through winter mixed layer entrainment in the subtropical-midlatitude North Atlantic.It is shown that the wintertime SST anomalies can be skillfully predicted up to three months ahead in the tropical Atlantic, eighteen months in the eastern subtropical Atlantic, and three years east of Newfoundland based on the first-mode baroclinic Rossby wave adjustment. Using wind stress data from NCEP-NCAR, a prediction of the future low-frequency SST variability has been made.更多还原