Convection Parameterization and Climate Simulation in the National Center for Atmospheric Research (NCAR) Community Climate System Model

NCAR社区气候系统模式（CCSM）中的两个缺陷被认为与模式中对流的参数化有关。因此，该模型偏向于弱的季节内变化在热带大气和过度降水在阿拉伯半岛，与观测相比。由于CCSM的广泛使用，因此进行研究以解决这些问题非常重要。本研究项目的目标是通过关注模式中的对流参数化来解决这些问题。具体而言，调查旨在实现以下基本科学目标：（一）了解对流如何与不同气候状况中的大尺度过程相互作用;（二）纳入观测数据以改进CCSM中的对流参数化;（三）改进CCSM中对流和大气状态的模拟时间变率;（四）改进CCSM中的对流和大气状态的模拟时间变率;（五）改进CCSM中的对流和大气状态的模拟时间变率。（iv）确定CCSM中阿拉伯半岛降水模拟错误的原因并消除它。这项工作中使用的基本研究工具是NCAR CCM 3，它是CCSM的大气组成部分，和Zhang-McFarlane对流方案，以及热带和中纬度地区不同对流系统的实地观测数据。将使用统计和合成技术分析改进对流参数化的模拟，以检查热带季节内变率的改善。系统的初始趋势误差分析将应用于一系列精心设计的数值试验的模拟，以了解CCM 3中阿拉伯半岛夏季降水偏差大的原因。这项研究将导致改进对流参数化，更好地理解对流的作用，更好地模拟热带气候及其在NCAR CCM 3中的变率。这项研究很重要，因为它有可能改善对世界社会具有重大价值的气候预测和预测。

Two deficiencies in the NCAR Community Climate System Model (CCSM) are believed to be related to the parameterization of convection in the model. The model is thus biased toward weak intraseasonal variability in the tropical atmosphere and excessive precipitation in the Arabian Peninsula, compared to observations. Because of the wide use of the CCSM, it is important to conduct research to address them. The goal of this research project is to address these issues by focusing on convective parameterization in the model. Specifically, the investigation aims to achieve the following fundamental scientific objectives: (i) Understand how convection interacts with the large-scale processes in different climate regimes; (ii) Incorporate observational data to improve convective parameterization in CCSM; (iii) Improve the simulated temporal variability of convection and the atmospheric state in CCSM; (iv) Determine the cause of the erroneous precipitation simulation over the Arabian Peninsula in CCSM and eliminate it.The basic research tools used in this work are the NCAR CCM3, which is the atmospheric component of CCSM, and the Zhang-McFarlane convection scheme, together with field observational data from different convection regimes in the tropics and midlatitudes. Simulations with improved convective parameterization will be analyzed using statistical and composite techniques to examine the improvement in the tropical intraseasonal variability. Systematic initial tendency error analysis will be applied to simulations from a series of carefully designed numerical experiments to understand the causes of large summer precipitation bias in the Arabian Peninsula in CCM3. The research should result in an improved convective parameterization, a better understanding of the role of convection and a better simulation in tropical climate and its variability in the NCAR CCM3. This research is important because it has potential to improve climate predictions and projections, which are of great value to world societies.