Toward Eliminating the Double Inter-Tropical Convergence Zone and Improving El Nino/Southern Oscillation Simulation in the NCAR Community Climate System Model Version 3 (CCSM3)

这是一个继续项目，重点是减轻双重热带辐合带（ITCZ）问题，并改善完全耦合的NCAR社区气候系统模式CCSM 3中厄尔尼诺和南方涛动（ENSO）的模拟。这些都是CCSM 3中最基本的缺陷之一。基本的研究工具是CCSM 3和改进的Zhang-McFarlane对流方案。将分析改进对流方案的耦合模式积分，以检验ITCZ和ENSO模拟的改进。将用原始和改进的对流方案进行短期（=10年）数值试验，以了解对流和大尺度环流之间的相互作用，以及对流参数化在消除双ITCZ中的作用。厄尔尼诺/南方涛动模拟将侧重于赤道地区纬向风应力在改进太平洋对流模拟方面的作用，以及增强的马登-朱利安振荡变率在增加模拟的厄尔尼诺/南方涛动周期性方面的作用。 智力优点：PI将（1）改进ITCZ降水的模拟，以消除CCSM 3中的双重ITCZ问题，（2）通过精心设计的数值试验，提高对对流参数化在双重ITCZ问题中的作用的科学理解，（3）改进ENSO周期性的模拟，以及（4）找到改进的原因，特别是，CCSM 3中地面风应力和增强的MJO模拟的作用。这项工作的完成将为以下方面提供新的见解：（1）新的积云对流参数化将导致ITCZ模拟的改进，以及（2）导致CCSM 3中最基本模式缺陷缓解的过程。这项研究将导致一个改进的气候系统模型，该模型正被全球气候研究界用于广泛的气候变化research.它还为研究生提供学习经验和培训。

This is a continuation project with a focus on mitigating the double Inter-Tropical Convergence Zone (ITCZ) problem and to improve the simulation of El Nino and Southern Oscillation (ENSO) in the fully coupled NCAR Community Climate System Model, CCSM3. These are amongst the most fundamental deficiencies in CCSM3. The basic research tools used are the CCSM3 and the improved Zhang-McFarlane convection scheme. The coupled model integrations with improved convection scheme will be analyzed to examine the improvement of ITCZ and ENSO simulations. Short term (=10 years) numerical experiments with both the original and improved convection scheme will be conducted to understand the interaction between convection and the large-scale circulation, and the role of convection parameterization in the elimination of double ITCZ. The ENSO simulation will focus on the role of the zonal wind stress off the equatorial region in relation to the improved simulation of convection in the Pacific and the role of enhanced Madden-Julian Oscillation (MJO) variability in increasing the periodicity of the simulated ENSO cycle. Intellectual merit: The PI will (1) Improve the simulation of the ITCZ precipitation to eliminate the double ITCZ problem in CCSM3, (2) Improve scientific understanding of the role of convection parameterization in the double ITCZ problem through carefully designed numerical experiments, (3) Improve the simulation of ENSO periodicity, and (4) Find the causes of the improvements, in particular, the roles of surface wind stress and enhanced MJO simulation in the CCSM3. Completion of this work will offer new insights into: (1) Ways the new cumulus convection parameterization will result in an improved simulation of ITCZ, and (2) Processes that results in the mitigation of the most fundamental model deficiencies in CCSM3Broader impacts: The research will lead to an improved climate system model that is being used worldwide by the climate research communities for a wide spectrum of climate change research. It also provides learning experiences and training for a graduate student.