Collaborative Research: Understanding Climate Feedbacks and 3-D Global Warming Patterns in Global General Circulation Climate Models

首席研究员（PI）成功开发了一个新的分析框架，以诊断全球变暖研究的气候反馈。新的框架，被称为气候反馈响应分析方法（CFRAM），不同于现有的方法，因为它允许一个线性地确定部分温度变化由于外部强迫和由于个别反馈过程或代理，如云，水汽，垂直和水平的能量传输。这些局部温度变化是可加的，它们的和就是总的温度变化。PI将应用CFRAM来分析和理解地表和大气温度的空间变暖模式，以响应人为温室气体，使用理想化全球气候模型（GCM）和完全耦合的国家大气研究中心（NCAR）社区气候系统模型3（CCSM 3）气候模拟的输出，以及现有的政府间气候变化专门委员会（气专委）-第四次评估报告（AR 4）GCM气候模拟。PI还将比较新的反馈分析与现有技术。这将有助于揭示IPCC-AR 4气候模拟得出的气候敏感性在模型间大幅度扩散的根源。还将分析使用CCSM 3与改进的对流参数化的耦合模式集成，以探索气候反馈和敏感性对模式物理参数化的依赖性。1）探讨在完全物理参数化的耦合大气环流模式下，应用CFRAM从外部强迫和各种物理反馈过程中分离出个体对总温度变化的贡献的可行性。2)阐明（a）地表和大气温度、（B）低纬度和高纬度以及（c）陆地和海洋之间变暖模式不对称的动力学/热力学根源。3)利用IPCC-AR 4气候模拟的结果，分析外部强迫、水汽反馈、云反馈、地面扰动反馈、地面湍流感热和潜热通量反馈的三维结构对全球变暖模式间传播及其空间分布的贡献。该研究旨在了解由于人为温室气体增加和气候系统反馈过程导致的全球气候变暖的基本问题。这项研究的更广泛的影响包括更好地量化每个反馈过程在气候变化中的作用，以及更定量地了解全球变暖的空间模式。研究生和博士后研究人员也将接受气候变化科学方面的教育和培训。

The lead Principal Investigator (PI) has successfully developed a new analysis framework to diagnose climate feedbacks for global warming studies. The new framework, referred to as the climate feedback response analysis method (CFRAM), differs from existing approaches in that it allows one to determine linearly the partial temperature changes due to external forcing and due to individual feedback processes or agents such as clouds, water vapor, and vertical and horizontal energy transport. These partial temperature changes are addable and their sum gives the total temperature change. The PIs will apply the CFRAM for analyzing and understanding spatial warming patterns of the surface and the atmospheric temperatures in response to anthropogenic greenhouse gases using outputs from an idealized global climate model (GCM) and the fully coupled National Center for Atmospheric Research (NCAR) Community Climate System Model 3 (CCSM3) climate simulations, as well as the existing Intergovernmental Panel on Climate Change (IPCC)-Assessment Report 4 (AR4) GCM climate simulations. The PIs will also compare the new feedback analysis with an existing technique. This will help to shed light on the sources of the large inter-model spread of climate sensitivity derived from IPCC-AR4 climate simulations. Coupled model integrations using CCSM3 with an improved convective parameterization will also be analyzed to explore the dependency of climate feedbacks and sensitivities to model physical parameterizations. The main objectives of the research are: 1) To explore the feasibility of applying the CFRAM to isolating individual contributions to the total temperature change from the external forcing and various physical feedback processes in the context of coupled GCMs with full physical parameterizations. 2) To shed light on the dynamical/thermodynamic origins of the warming pattern asymmetries between (a) surface and atmospheric temperatures, (b) low and high latitudes, and (c) land and ocean. 3) To identify the contributions to the inter-model spread of the global warming and its spatial pattern due to the inter-model spreads of the 3-D structure of the external forcing, water vapor feedback, cloud feedback, surface albedo feedback, and surface turbulent sensible and latent heat flux feedbacks using the outputs from IPCC-AR4 climate simulations. The research aims to understand fundamental issues in global climate warming due to increases in anthropogenic greenhouse gases and feedback processes in the climate system. Broader impacts of this research include better quantification of the role of each feedback process in climate change and a more quantitative understanding of global warming spatial patterns. Graduate students and postdoctoral researchers will also be educated and trained in climate change science.