Does increasing the spatial resolution of a regional climate model improve the simulated daily precipitation?
Does increasing the spatial resolution of a regional climate model improve the simulated daily precipitation?
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DOI：
10.1007/s00382-012-1568-9
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发表时间：
2013-09-01
期刊：
影响因子：
4.6
通讯作者：
Stephenson, David B.
中科院分区：
文献类型：
--
作者：
Chan, Steven C.;Kendon, Elizabeth J.;Stephenson, David B.
三个不同的分辨率（50，12，和1.5公里）的区域气候模式模拟的能力进行了比较，以模拟中等和高的日降水量在英国南部的事件。对流允许的1.5公里模拟进行对流参数化。在以前的研究中，增加分辨率（特别是从50到12公里）被发现，以改善地形降水的代表性。50公里的模拟低估了威尔士山区的平均降水量，事件强度往往太弱，这种偏见是减少在12和1.5公里的模拟夏季和冬季。在英格兰东南部低地，夏季极端大多是对流，增加分辨率并不一定会导致模拟的改善。对于12公里的模拟，模拟的每日极端事件过于强烈。尽管在1.5公里模拟中夏季每日极端事件的平均强度有所改善，但由于超过高阈值的事件太多，该模拟的平均偏差较差。空间密度和集群的夏季极端在英格兰东南部的12公里和1.5公里的模拟模拟都很差。一般来说，我们没有发现任何明确的证据表明，1.5公里的模拟上级12公里的模拟，或反之亦然，在日常水平。
Three different resolution (50, 12, and 1.5 km) regional climate model simulations are compared in terms of their ability to simulate moderate and high daily precipitation events over the southern United Kingdom. The convection-permitting 1.5-km simulation is carried out without convective parametrisation. As in previous studies, increasing resolution (especially from 50 to 12 km) is found to improve the representation of orographic precipitation. The 50-km simulation underestimates mean precipitation over the mountainous region of Wales, and event intensity tends to be too weak; this bias is reduced in both the 12- and 1.5-km simulations for both summer and winter. In south-east England lowlands where summer extremes are mostly convective, increasing resolution does not necessary lead to an improvement in the simulation. For the 12-km simulation, simulated daily extreme events are overly intense. Even though the average intensity of summer daily extremes is improved in the 1.5-km simulation, this simulation has a poorer mean bias with too many events exceeding high thresholds. Spatial density and clustering of summer extremes in south-east England are poorly simulated in both the 12- and 1.5-km simulations. In general, we have not found any clear evidence to show that the 1.5-km simulation is superior to the 12-km simulation, or vice versa at the daily level.