海洋环流与波动重点实验室知识库

为研究模式模拟南太平洋副热带偶极子的能力, 本文利用(Coupled Model Intercomparison Project Phase 5, CMIP5)模式的模拟数据评估了 15 种模式模拟南太平洋副热带偶极子(South Pacific Subtropical Dipole, SPSD)时空分布的效果, 并予以评分。结果表明: 其中 10 种模式可以模拟出完整 的SPSD生成发展过程, 且SPSD的主要区域与观测较为接近, 但其余5种模式在模拟强度、位置与 观测有较大出入; 所有模式在模拟 SPSD 生成阶段时比观测提前一个月出现偶极模态, 1/4 的模式海 表面温度(sea surface temperature, SST)偶极异常可以追溯到 6 个月之前;潜热通量与 SST 的时空分布 显示, 潜热通量是影响偶极模态生成发展的主要因素。模态的变化主要受大气环流的调制, 在模态发 展最强时部分模式的正极上方有正潜热通量异常, 即海洋向大气传递热量。分析显示模式模拟海气 耦合过程中的 SST 模拟强度较观测偏强, 气压方面与观测较为接近。 
 

We applied 15 CMIP5 (Coupled Model Intercomparison Project Phase 5) models to stimulate temporal and spatial distribution of the South Pacific Subtropical Dipole (SPSD), from which the performance of the 15 models were compared and scored. The results show that 10 of them could present a complete SPSD in development course, and the main areas of SPSD are similar to the observations. However, the rest 5 models showed large differences in the intensity and the position of observation of the SPSD. Most of the CMIP5 models showed a one-month lead to the observation result in the initial phase of SPSD, and about one third of the models could display the dipole anomaly of sea surface temperature 3-6 months in the past retroactively. As shown in the temporal and spatial distribution, latent heat flux is the main factor affecting the development of SPSD under an atmospheric circulation anomaly. For the SPSD mature phase, some models could show a positive latent heat flux anomaly over the positive pole, indicating that the ocean would feedback to the atmospheric circulation in latent heat flux and form a negative feedback circulation. Therefore, these CMIP5 models perform better in sea-surface-temperature simulation than sea-surface-pressure simulation.