海气耦合模式中热带SST偏差的来源与发展过程研究

海气耦合模式是进行气候研究和气候预测的重要工具，但是，当前非通量调整海气耦合模式的模拟都存在显著的热带偏差问题，其主要的表现之一是热带气候态海表温度（SST）模拟偏差，由于海气耦合系统的复杂性，其原因仍不完全清晰。要从根本上解决热带偏差问题，首先应是理解热带偏差的来源、发展以及维持过程。本研究将围绕大气模式和海洋模式初始耦合阶段热带SST偏差的来源与发展过程这一核心内容，在CCSM4的框架下设计相关数值试验，以隐式海表温度偏差和海洋动力偏差的分析入手，结合单独大气模式和单独海洋模式的模拟结果，从印度洋、太平洋和大西洋三个大洋分别入手定量评估大气模式和海洋模式对热带SST偏差的贡献，逐步阐明热带SST偏差的发展维持机制，为模式的改进与发展提供建议与参考。

The coupled ocean-atmosphere general circulation models (CGCMs) widely used in the global climate research can provide credible simulations of fundamental properties of the climate system. However, the tropical sea surface temperature (SST) biases, such as the too cold tongue, warm SST bias in the eastern tropical basins and a reversed zonal SST gradient along the Atlantic equator, are the classical problem for CGCMs even now. Since the air-sea coupled system is quite complex, to understand the mechanism and feedback process related to these tropical SST biases still remains a big challenge. To understand the source and development process of tropical SST bias is the first and foremost task of study. In this study, in order to identify and quantify inherent errors in the atmosphere-land model and the ocean-sea ice model components of Community Climate System Model version 4 (CCSM4), and their contributions, especially the ocean dynamics bias contributions, to the tropical SST bias in the CCSM4, we propose a new method of diagnosis named implicit SST bias and apply it to a series of CCSM4 experiments simulations. In an effort to identify the exact processes that cause the tropical SST biases, here we focus on the initial development of the SST bias by through the comparisons and analysis of the series of experiments results. Ultimately, we wish to identify processes and/or parameterizations in the CGCMs that are responsible for generating the tropical SST bias and provide suggestions for the CGCMs improvement.