Collaborative Research: Evaluating the Roles of Factors Critical to MJO Simulations Using the NCAR CAM3 with Deterministic and Stochastic Convection Parameterization Closures

协作研究：使用具有确定性和随机对流参数化闭包的 NCAR CAM3 评估 MJO 模拟的关键因素的作用

• 批准号: 1015964
• 负责人: Guang Zhang
• 金额: $ 36.71万
• 依托单位: University of California-San Diego Scripps Inst of Oceanography
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-05-01 至 2015-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1015964&HistoricalAwards=false
• 关键词: Collaborative; Research; Evaluating; Roles; Factors

The Madden-Julian Oscillation (MJO) is a large-scale pattern of precipitation and atmospheric circulation anomalies which forms over the Indian Ocean and propagates slowly eastward towards the central equatorial Pacific Ocean. Impacts of the MJO are felt over much of the earth, and the presence of the MJO in the central equatorial Pacific Ocean exerts a strong modulation of hurricane activity in the Gulf of Mexico. Work conducted under this grant is intended to improve the representation of the MJO in global climate models (GCMs), particularly the National Center for Atmospheric Research Community Atmosphere Model (CAM). The questions addressed in the research focus on specific factors believed to be essential to a successful MJO simulation: 1) How important is convective momentum transport [CMT, occurring in cumulus clouds] in the MJO simulation? The objective of addressing this question is to understand what role convective momentum transport plays in westerly wind bursts accompanying MJOs. 2) What are the roles of convective versus stratiform heating, shallow versus deep convection, and stochastic versus deterministic convection closure in the MJO simulation? The objective is to determine how each of the processes affects the MJO simulation [here stratiform refers to the flat, upper-level "anvils" associated with deep cumulus clouds]. 3) How do these roles depend on the MJO phases in the MJO development process? The objective of answering this question is to understand what role each process plays during different stages of the MJO evolution. Motivation for the work comes from the difficulty in simulating and predicting the MJO using weather and climate models.The work has broader impacts due to the many worldwide impacts of the MJO on weather and climate, as better representation of the MJO in models is a first step in generating useful MJO forecasts. In addition, the MJO is an important test case for the parameterization of convection and cloud processes in climate models, which would increase our confidence in predictions and projections of climate change. Beyond these broader impacts, the project also promotes science education through undergraduate teaching and outreach activities to high schools.

马登-朱利安涛动（MJO）是一种大尺度的降水和大气环流异常，它形成于印度洋上空，并缓慢向东传播到赤道中太平洋。 MJO的影响在地球的大部分地区都能感受到，并且MJO在赤道太平洋中部的存在对墨西哥湾的飓风活动产生了强烈的调制作用。 在该资助下进行的工作旨在提高MJO在全球气候模型（GCM）中的代表性，特别是国家大气研究中心社区大气模型（CAM）。 在研究中解决的问题集中在特定的因素，认为是必不可少的一个成功的MJO模拟：1）有多重要是对流动量输送[CMT，发生在积云]在MJO模拟？解决这个问题的目的是了解对流动量输送在伴随MJO的西风爆发中起什么作用。 2)在MJO模拟中，对流与层状加热、浅对流与深对流、随机对流闭合与确定性对流闭合的作用是什么？目的是确定每个过程如何影响MJO模拟[这里层状是指与深积云相关的平坦的上层“砧”]。 3)这些角色如何依赖于MJO开发过程中的MJO阶段？ 回答这个问题的目的是了解在MJO演变的不同阶段，每个过程扮演什么样的角色。 这项工作的动机来自于使用天气和气候模式模拟和预测MJO的困难。由于MJO对天气和气候的许多全球影响，这项工作具有更广泛的影响，因为在模型中更好地代表MJO是生成有用的MJO预报的第一步。 此外，MJO是气候模式中对流和云过程参数化的重要测试案例，这将增加我们对气候变化预测和预测的信心。 除了这些更广泛的影响，该项目还通过本科教学和推广活动，以高中促进科学教育。