Challenging some tenets of Regional Climate Modelling
Challenging some tenets of Regional Climate Modelling
复制标题
DOI：
10.1007/s00703-008-0292-9
复制
发表时间：
2008-08
影响因子：
2
通讯作者：
R. Laprise;R. de Elía;D. Caya;S. Biner;P. Lucas‐Picher;E. Diaconescu;M. Leduc;A. Alexandru;L. Šeparović;Canadian Network for Regional Climate Modelling and Diagnostics-Canadian-Network-for-Regional-Climate-Modelling-and-1419937314
中科院分区：
文献类型：
--
作者：
R. Laprise;R. de Elía;D. Caya;S. Biner;P. Lucas‐Picher;E. Diaconescu;M. Leduc;A. Alexandru;L. Šeparović;Canadian Network for Regional Climate Modelling and Diagnostics-Canadian-Network-for-Regional-Climate-Modelling-and-1419937314
嵌套区域气候模型（RCM）越来越多地用于气候变化预测，以实现空间分辨率，而耦合的全球气候模型在计算上却难以实现。 RCM 通常被认为是一种复杂的放大镜，用于执行动态降尺度，即在作为依赖时间的横向边界条件提供的大尺度流动上添加精细尺度的细节。区域气候建模是一种相对较新的方法，发起于不到二十年前。人们对这种方法的兴趣迅速增长，因为它提供了一种计算上负担得起的方法，可以进入具有及时社会相关性的有吸引力的应用，例如高分辨率气候变化预测和季节预测。然而，需要进行基础研究，旨在牢固地确定该技术的优点和局限性。本文综合了一系列关于嵌套方法的优点和缺点的调查结果，这些调查是由我们团队的一些成员在大约十年前发起的。这篇简短的论文重新审视了区域气候模拟实践者中一些普遍接受的概念，其形式将受到挑战的四个原则：（1）RCM 能够生成作为横向边界条件提供的驱动场中不存在的小尺度特征； (2)生成的小尺度具有适当的幅度和统计量； (3) 生成的小尺度准确地代表了在不受分辨率限制的情况下将出现在驾驶数据中的那些尺度； (4) 在执行动态降尺度时，RCM 就像一种复杂的放大镜一样运行，即生成的小尺度是针对给定的一组横向边界条件 (LBC) 唯一定义的。从最后两个原则的部分失败中出现了内部可变性的概念，由于施加的横向边界条件所施加的控制，内部可变性通常被认为在单向嵌套模型中可以忽略不计。还讨论了第五个原则，涉及在 LBC 处用于驱动 RCM 的大规模 RCM 域内的处理。我们在文章的结尾呼吁 RCM 社区在基础研究上投入更多精力，以解决一些挥之不去的问题，否则可能会危及该工具的可信度。
Nested Regional Climate Models (RCMs) are increasingly used for climate-change projections in order to achieve spatial resolutions that would be computationally prohibitive with coupled global climate models. RCMs are commonly thought to behave as a sort of sophisticated magnifying glass to perform dynamical downscaling, which is to add fine-scale details upon the large-scale flow provided as time-dependent lateral boundary condition.Regional climate modelling is a relatively new approach, initiated less than twenty years ago. The interest for the approach has grown rapidly as it offers a computationally affordable means of entering into appealing applications of timely societal relevance, such as high-resolution climate-change projections and seasonal prediction. There exists however a need for basic research aiming at establishing firmly the strengths and limitations of the technique.This paper synthesises the results of a stream of investigations on the merits and weaknesses of the nested approach, initiated almost a decade ago by some members of our team. This short paper revisits some commonly accepted notions amongst practitioners of Regional Climate Modelling, in the form of four tenets that will be challenged: (1) RCMs are capable of generating small-scale features absent in the driving fields supplied as lateral boundary conditions; (2) The generated small scales have the appropriate amplitudes and statistics; (3) The generated small scales accurately represent those that would be present in the driving data if it were not limited by resolution; (4) In performing dynamical downscaling, RCMs operate as a kind of sophisticated magnifying glass, in the sense that the small scales that are generated are uniquely defined for a given set of lateral boundary conditions (LBC). From the partial failure of the last two tenets emerges the notion of internal variability, which has often been thought to be negligible in one-way nested models due to the control exerted by the imposed lateral boundary conditions. A fifth tenet is also discussed, relating to the handling within the RCM domain of the large scales used to drive the RCM at the LBC. We close the article with an appeal to the RCM community to spend more effort in basic research in order to tackle a number of lingering issues that otherwise could jeopardize the credibility of the tool.