Regional climate modeling on European scales: a joint standard evaluation of the EURO-CORDEX RCM ensemble
Regional climate modeling on European scales: a joint standard evaluation of the EURO-CORDEX RCM ensemble
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DOI：
10.5194/gmd-7-1297-2014
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发表时间：
2014-01-01
影响因子：
5.1
通讯作者：
Wulfmeyer, V.
中科院分区：
文献类型：
--
作者：
Kotlarski, S.;Keuler, K.;Wulfmeyer, V.
EURO-CORDEX 是一项国际气候降尺度倡议，旨在为欧洲提供高分辨率气候情景。这里介绍了 ERA-Interim 驱动的 EURO-CORDEX 区域气候模型 (RCM) 集合的评估。该研究记录了各个模型在代表 1989-2008 年期间欧洲气候基本时空模式方面的表现。模型评估重点关注近地表气温和降水，并使用E-OBS数据集作为观测参考。该集合由 7 个不同模型以 12 公里（9 个实验）和 50 公里（8 个实验）的网格分辨率进行的 17 次模拟组成。根据月度和季节性平均值计算的几个性能指标用于评估欧洲大陆八个子域的模型性能。将结果与 ERA40 驱动的 ENSEMBLES 模拟的结果进行比较。分析证实了 RCM 捕获欧洲气候基本特征的能力，包括其空间和时间的变化。但它也发现了选定指标、地区和季节的模拟中不可忽视的缺陷。季节和区域平均温度偏差大多小于 1.5 摄氏度，而降水偏差通常位于 +/- 40% 范围内。一些偏差特征，例如大多数季节和欧洲大部分地区的主要寒冷和潮湿偏差以及欧洲南部和东南部的温暖和干燥夏季偏差反映了常见的模型偏差。对于大型欧洲子域的平均季节平均量，无法识别出增加空间分辨率（12 公里与 50 公里）的明显好处。 EURO-CORDEX 系综的偏差范围大部分与 ENSEMBLES 模拟的偏差范围相对应，但可以发现模型性能的一些改进（例如，不太明显的南欧暖夏偏差）。一个模型的不同配置之间的温度偏差分布可能与不同模型之间的温度偏差分布具有相似的幅度，这表明物理参数化和实验设置中的特定选择对模型性能有很大影响。基于一些简单可重复的指标，本研究量化了用于欧洲区域气候模拟的 RCM 目前可达到的精度，并为未来模型开发提供了质量标准。
EURO-CORDEX is an international climate downscaling initiative that aims to provide high-resolution climate scenarios for Europe. Here an evaluation of the ERA-Interim-driven EURO-CORDEX regional climate model (RCM) ensemble is presented. The study documents the performance of the individual models in representing the basic spatiotemporal patterns of the European climate for the period 1989-2008. Model evaluation focuses on near-surface air temperature and precipitation, and uses the E-OBS data set as observational reference. The ensemble consists of 17 simulations carried out by seven different models at grid resolutions of 12 km (nine experiments) and 50 km (eight experiments). Several performance metrics computed from monthly and seasonal mean values are used to assess model performance over eight subdomains of the European continent. Results are compared to those for the ERA40-driven ENSEMBLES simulations.The analysis confirms the ability of RCMs to capture the basic features of the European climate, including its variability in space and time. But it also identifies nonnegligible deficiencies of the simulations for selected metrics, regions and seasons. Seasonally and regionally averaged temperature biases are mostly smaller than 1.5 degrees C, while precipitation biases are typically located in the +/- 40% range. Some bias characteristics, such as a predominant cold and wet bias in most seasons and over most parts of Europe and a warm and dry summer bias over southern and southeastern Europe reflect common model biases. For seasonal mean quantities averaged over large European subdomains, no clear benefit of an increased spatial resolution (12 vs. 50 km) can be identified. The bias ranges of the EURO-CORDEX ensemble mostly correspond to those of the ENSEMBLES simulations, but some improvements in model performance can be identified (e. g., a less pronounced southern European warm summer bias). The temperature bias spread across different configurations of one individual model can be of a similar magnitude as the spread across different models, demonstrating a strong influence of the specific choices in physical parameterizations and experimental setup on model performance. Based on a number of simply reproducible metrics, the present study quantifies the currently achievable accuracy of RCMs used for regional climate simulations over Europe and provides a quality standard for future model developments.