Collaborative Research: Tropical Variability in a New Generation of Coupled Climate Simulations with Explicitly Resolved Convection

合作研究：新一代耦合气候模拟中的热带变化与显式解析的对流

• 批准号: 1119999
• 负责人: David Randall
• 金额: $ 24.99万
• 依托单位: Colorado State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1119999&HistoricalAwards=false
• 关键词: Collaborative; Research; Tropical; Variability; New

Research is conducted on simulations performed with the superparameterized (SP) version of the Community Climate System Model (CCSM, version 3), or SP-CCSM. The atmospheric component model used in a coupled climate model typically uses a parameterization for convection, in which the effects of convection are estimated without actually resolving the convection. In superparameterization, the parameterization is replaced by a cloud resolving model at each point in the model's horizontal grid. In this way the climate model gains some of the benefits of a global cloud resolving model without the enormous computational expense of running such a high-resolution (7km or less) nonhydrostatic model over the globe. Based on a 20-year simulation performed as preliminary work, SP-CCSM produces a better tropical simulation than CCSM3, including improvements in the periodicity of El Nino/Southern Oscillation events, reduction in the classical double-ITCZ bias, and a more credible simulation of the Madden-Julian Oscillation (MJO).Two research objectives are addressed in this research: first, SP-CCSM and its component atmospheric model are used to evaluate the roles of surface fluxes, air-sea interactions, and small-scale convective processes in producing MJO events. This research also considers the mechanisms through which the MJO affects the Asian summer monsoon. Second, the work seeks to understand the effect of the MJO on El Nino/Southern Oscillation events in the equatorial Pacific.The work has broader impacts through its potential to forecasts of MJO events, which have consequences for the Asian summer monsoon and weather in the United States. Research results may also lead to improvements in the parameterization of tropical convection in weather and climate models. In addition, the project supports a postdoctoral researcher, thereby providing for the next generation of scientists in this field.

研究是通过社区气候系统模型（CCSM，版本 3）的超参数化（SP）版本或 SP-CCSM 进行的模拟进行的。 耦合气候模型中使用的大气成分模型通常使用对流参数化，其中估计对流的影响而不实际解析对流。在超参数化中，参数化被模型水平网格中每个点的云解析模型所取代。通过这种方式，气候模型获得了全球云解析模型的一些好处，而无需在全球范围内运行如此高分辨率（7公里或更小）非静水力模型的巨大计算费用。基于作为前期工作进行的 20 年模拟，SP-CCSM 产生了比 CCSM3 更好的热带模拟，包括改善厄尔尼诺/南方涛动事件的周期性、减少经典的双 ITCZ 偏差以及对马登-朱利安涛动 (MJO) 的更可信的模拟。本研究涉及两个研究目标：首先，SP-CCSM 及其 成分大气模型用于评估地表通量、海气相互作用和小规模对流过程在产生 MJO 事件中的作用。 这项研究还考虑了 MJO 影响亚洲夏季风的机制。 其次，这项工作旨在了解 MJO 对赤道太平洋厄尔尼诺/南方涛动事件的影响。这项工作通过其预测 MJO 事件的潜力而产生更广泛的影响，这些事件对亚洲夏季季风和美国的天气产生影响。 研究结果还可能导致天气和气候模型中热带对流参数化的改进。 此外，该项目还支持一名博士后研究员，从而为该领域的下一代科学家提供支持。