Understanding the Dynamic Land-Atmosphere System: Multiple Equilibrium States and Climate Variability

了解动态陆地-大气系统：多重平衡状态和气候变化

• 批准号: 0531485
• 负责人: Guiling Wang
• 金额: --
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-09-01 至 2010-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0531485&HistoricalAwards=false
• 关键词: Understanding; Dynamic; Land; Atmosphere; System

Several modeling studies indicate that terrestrial biosphere-atmosphere interactions may give rise to the existence of multiple equilibria in the Earth's climate system. However, diagnosing whether multiple equilibrium states exist in global climate system models and why they exist where they do is extremely challenging; the impact of multiple equilibria on the long-term variability and changes of regional-global climates is not well understood. The research objectives of this project are to two-fold: first, to understand the mechanisms responsible for the existence of multiple biosphere-atmosphere equilibria in certain climate models and over certain regions; second, to understand the natural variability of regional climate systems that do possess multiple equilibrium states.Intellectual merit. Based on a conceptual dynamical model for vegetation-precipitation interactions, the PI develops four hypotheses. These hypotheses will be evaluated using a global circulation model developed by the National Center for Atmospheric Research and models that will be derived from it by changing the quantification of certain properties or changing the parameterization of certain processes within the model. Completion of this work will offer new insights into:1. The existence of multiple equilibrium states in the global biosphere-atmosphere system as simulated by global general circulation models, and 2. An improved understanding of climate variability, climate changes, and their model dependence.Broader impacts. The research will provide a better understanding about how a system with multiple equilibria behaves, which may increase the ability of affected populations to adapt to and mitigate the impact of potential climate transitions between different equilibria. This project provides learning experiences and training for undergraduate and graduate-level students in the field of climate system modeling and climate-vegetation interactions.

一些模拟研究表明，陆地生物圈-大气相互作用可能导致地球气候系统存在多重平衡。然而，诊断全球气候系统模型中是否存在多个平衡态以及它们存在的原因是极其具有挑战性的；多个平衡态对区域-全球气候的长期变异性和变化的影响还没有被很好地理解。这个项目的研究目标有两个：第一，了解在某些气候模型和某些区域上存在多种生物圈-大气平衡的机制；第二，了解确实具有多种平衡状态的区域气候系统的自然变异性。基于植被-降水相互作用的概念动力学模型，PI提出了四个假设。这些假设将使用由国家大气研究中心开发的全球环流模型以及通过改变模型中某些属性的量化或某些过程的参数化来派生的模型进行评估。这项工作的完成将为以下方面提供新的见解：1.由全球大气环流模式模拟的全球生物圈-大气系统中多种平衡态的存在；2.对气候变异性、气候变化及其模式依赖性的更好理解。这项研究将更好地理解具有多个均衡的系统的行为，这可能会增加受影响人口适应和减轻不同均衡之间潜在气候转变的影响的能力。该项目为本科生和研究生提供气候系统建模和气候-植被相互作用领域的学习经验和培训。