Obtaining diverse behaviors in a climate model without the use of flux adjustments
Obtaining diverse behaviors in a climate model without the use of flux adjustments
复制标题
在不使用通量调整的情况下获得气候模型中的不同行为
DOI：
10.1002/jgrd.50304
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
M. Allen
中科院分区：
文献类型：
--
作者：
K. Yamazaki;D. Rowlands;T. Aina;A. Blaker;A. Bowery;N. Massey;Jonathan Miller;C. Rye;S. Tett;D. Williamson;Y. Yamazaki;M. Allen
一些研究已经着手通过扰动单一气候模式中的参数来获得一系列大气和海洋模式行为（扰动物理学集合：PPE）。早期的研究使用浅层平板海洋或通量调整的海洋-大气耦合模式来获得以气候敏感性为特征的广泛行为。最近的一项研究报告说，在没有通量调整的情况下，35个耦合模式的PPE的灵敏度范围相对较窄（2.2-3.2°C），这引发了一个问题，即以前的宽范围是否是使用不处于大气层顶（TOA）能量平衡的模式的人为因素。此外，与耦合模式相互比较项目第3阶段（CMIP 3）等多模式集合（MME）中所展示的情况相比，没有PPE实验报告海洋行为的大范围传播。在这项工作中，我们使用包含10，000个组合的空间填充设计随机扰动耦合海洋大气环流模型的模型参数。该集合在climateprediction.net的分布式计算平台上在固定的工业前强制下运行，而无需通量调整。我们对第二个20，000成员的系综进行重新采样，其中扰动以来自第一个系综的TOA通量为条件，以便在针对一系列行为的同时不会从现实的基态显著漂移。与CMIP 3集合相比，目标集合中的模型显示了现实的区域控制气候，尽管全球平均表面温度存在偏差。目标集合的预测平衡气候敏感性的范围远小于通量调整获得的范围，但大于CMIP 3集合或上述最近研究中35模式未经通量调整的PPE的范围。目标集合中的大西洋经向翻转环流的强度分布与CMIP 3集合中的强度分布一样宽。我们的结论是，通量调整不是在扰动物理系综中获得广泛行为的先决条件。
A number of studies have set out to obtain a range of atmosphere and ocean model behavior by perturbing parameters in a single climate model (perturbed physics ensemble: PPE). Early studies used shallow layer slab ocean or flux‐adjusted coupled ocean‐atmosphere models to obtain a broad range of behavior as characterized by climate sensitivity. A recent study reports a relatively narrow range of sensitivities (2.2–3.2°C) in a PPE of 35 coupled models without flux adjustment, raising the question whether previous broad ranges were an artifact of the use of models that were not in top‐of‐atmosphere (TOA) energy balance. Moreover, no PPE experiment has reported a large spread of behavior of the ocean compared to that exhibited in a multi‐model ensemble (MME) such as Coupled Model Intercomparison Project phase 3 (CMIP3). In this work, we randomly perturb model parameters of a coupled ocean‐atmosphere general circulation model using a space‐filling design containing 10,000 combinations. The ensemble is run over the distributed computing platform of climateprediction.net under fixed pre‐industrial forcing without flux adjustment. We resample a second, 20,000‐member, ensemble with perturbations conditioned on the TOA fluxes from the first ensemble to not drift significantly from a realistic base state while targeting a range of behavior. Models within the targeted ensemble show realistic regional control climates when compared to the CMIP3 ensemble, although there is a bias in global mean surface temperature. The range of predicted equilibrium climate sensitivities of the targeted ensemble is substantially smaller than that obtained with flux adjustment, but larger than the range in the CMIP3 ensemble or in the 35‐model un‐flux‐adjusted PPE in a recent study mentioned above. The Atlantic meridional overturning circulation in the targeted ensemble exhibits a spread in strength as wide as that found in the CMIP3 ensemble. We conclude that flux adjustment is not a pre‐requisite for obtaining a broad spread of behavior in a perturbed physics ensemble.
影响因子：
18.3
作者：
Rowlands, Daniel J.;Frame, David J.;Allen, Myles R.
通讯作者：
Allen, Myles R.