LAUSR

Evaluating a climate model’s fidelity (ability to simulate observed climate) is a critical step in establishing confidence in the model’s suitability for future climate projections, and in tuning climate model parameters. Model developers use their judgement in determining which trade-offs between different aspects of model fidelity are acceptable. However, little is known about the degree of consensus in these evaluations, and whether experts use the same criteria when different scientific objectives are defined. Here, we report on results from a broad community survey studying expert assessments of the relative importance of different output variables when evaluating a global atmospheric model’s mean climate. We find that experts adjust their ratings of variable importance in response to the scientific objective, for instance, scientists rate surface wind stress as significantly more important for Southern Ocean climate than for the water cycle in the Asian watershed. There is greater consensus on the importance of certain variables (e.g., shortwave cloud forcing) than others (e.g., aerosol optical depth). We find few differences in expert consensus between respondents with greater or less climate modeling experience, and no statistically significant differences between the responses of climate model developers and users. The concise variable lists and community ratings reported here provide baseline descriptive data on current expert understanding of certain aspects of model evaluation, and can serve as a starting point for further investigation, as well as developing more sophisticated evaluation and scoring criteria with respect to specific scientific objectives.摘要评估气候模式对观测到的现代气候的保真再现能力是气候模式研发中的关键环节.它决定模式是否适用于对未来气候预估, 也可以指导对模式参数的进一步调整. 模式开发人员通常基于他们自己的判断去综合考虑模式在不同方面的模拟性能并给出一个折衷方案. 但是, 这些评估在多大程度上是气候学家的共识呢?针对不同科学目标时, 专家们能否秉持同样的标准? 本研究以评估一个全球大气模式模拟的气候平均态为例, 完成了一次广泛的气候学家问卷调查, 用以研究气候学家对模式不同输出变量相对重要性的认识. 研究发现, 气候学家对各变量重要性的意见常随科学目标的不同而变化. 比如, 他们多认为表面风应力对南大洋气候显然比对亚洲流域的水循环更为重要. 此外, 大家对某些变量(比如:短波云强迫)的重要性往往比对其他变量(比如:气溶胶光学厚度)更有共识. 在参与调查的人员中, 气候模式研发经验在他们对这些问题的看法上几乎没有影响, 气候模式的开发人员和使用人员认识的差别也并不显著. 本文提供了一个简要的模式评估变量名单以及它们的相对重要性排名, 为目前模式评估的一些特定方面提供了一个基准性描述数据, 这也是未来研究中针对特定科学问题发展更深入评估和评分标准的新起点.