Variability of the Climate System

该项目旨在提高对当前气候的变率和可预测性的理解，特别是与北大西洋涛动（NAO）有关的变率和可预测性，在季节间到年代际的时间尺度上。 由于不可能在实际的全球气候系统中进行必要的受控实验来实现这一目标，耦合GCM模拟观测到的气候学和变率的大气环流模式将是调查的基本工具。气候将由一个多世纪的控制模拟和COLA的更新版本来代表（大气-海洋陆地研究中心）全球耦合GCM。 COLA耦合的GCM对低频气候变率的许多方面进行了真实的模拟，包括年际和年代际厄尔尼诺/拉尼娜，北大西洋，北太平洋和北极/南极振荡。 一系列的实验中，修改的GCM将有助于了解NAO的变化控制模拟中发现的机制。 这些实验将利用大气环流模式的异常耦合能力，在局部区域进行单向或完全耦合的大气-海洋或大气-陆地相互作用，同时指定其他地方的气候边界条件。 将被检查的机制是当地的大气-海洋耦合，当地的海洋动力学，热带SST异常的远程影响，耦合的大气-陆地过程，和随机大气强迫的作用。 该项目有可能在几个重要领域增进知识。 这些是：（1）了解低频NAO相关变率;（2）指出这种类型的内部气候变率是否是可预测的;（3）评估内部产生的气候变率是否足以解释上世纪北大西洋观测到的变率，或者是否必须寻求替代解释; 4）开发和评估一类新的实验，以了解耦合CMS中的气候变率。

AbstractATM-9907915SchneiderThe project is designed to enhance understanding of the variability and predictability of the current climate, especially that associated with the North Atlantic Oscillation (NAO), on inter-seasonal to inter-decadal time scales. Since it is impossible to do the type of controlled experiments necessary to accomplish this goal in the actual global climate system, a coupled GCM (general circulation model) that simulates the observed climatology and variability realistically will be the basic tool for the investigation.The climate will be represented by a multi-century control simulation with an updated version of the COLA (Center for Atmosphere-Ocean Land Studies) global coupled GCM. The COLA coupled GCM produces a realistic simulation of many aspects of low frequency climate variability, including interannual and decadal El Nino/La Nina, and the North Atlantic, North Pacific, and Arctic/Antarctic Oscillations. A series of experiments in which the GCM is modified will be made to help understand the mechanisms underlying the NAO variability found in the control simulation. These experiments will utilize the anomaly coupling capabilities of the GCM to allow one-way or fully coupled atmosphere-ocean or atmosphere-land interactions in localized regions, while specifying climatological boundary conditions elsewhere. The mechanisms that will be examined are local atmosphere-ocean coupling, local ocean dynamics, remote influence of tropical SST anomalies, coupled atmosphere-land processes, and the role of stochastic atmospheric forcing. The project has the potential to advance knowledge in several important areas. These are: 1) understanding low frequency NAO associated variability; 2) indicating whether this type of internal climate variability is or is not predictable; 3) evaluating whether internally generated climate variability is sufficient to explain observed variability over the North Atlantic over the last century, or whether alternative explanations must be sought; 4) developing and evaluating a new class of experiments to understand climate variability in coupled CMS.