Using an ultrahigh‐resolution regional climate model to predict local climatology
Using an ultrahigh‐resolution regional climate model to predict local climatology
复制标题
使用超高分辨率区域气候模型来预测当地气候
DOI：
10.1002/qj.2081
复制
发表时间：
2013
影响因子：
8.9
通讯作者：
P. Clark
中科院分区：
文献类型：
--
作者：
Changgui Wang;Richard G. Jones;M. Perry;Catrina Johnson;P. Clark
风险评价和环境影响评价的许多应用都需要在非常精细的空间尺度上获得局地中尺度气候的信息。目前的区域气候模式（RCMs）的网格分辨率通常在10至50公里之间，无法解析影响局部气候小尺度特征的局部地理特征。本文介绍了一种超高分辨率局地气候模式（LCM）系统，并演示了其在地形和海岸线对气候有重要影响的海岸带局地气候研究中的应用。LCM是由英国气象局统一模式（MetUM）发展而来的，基于非常高分辨率数值天气预报的概念。超高分辨率区域气候模拟是通过在12公里至~ 500米的空间分辨率范围内进行多重嵌套来实现的。在LCM的试点研究中，rcm在12、4、1.5和0.5 km网格分辨率下运行，模拟了英国南部海岸韦茅斯湾和波特兰港的中尺度气候。模拟期为1993 - 2002年的7 - 8月，模式结果与气象站时间序列进行了验证。结果表明，与1.5 km分辨率模式相比，500 m分辨率模式在模拟内部区域非常精细的局地中尺度气候模式方面具有附加价值，包括温度和风的日变化，如西南气流，以及波特兰岛与大陆之间的风道效应。在500米分辨率模型中，沿东南海岸和波特兰避风处也发现了较低的平均风速，特别是在波特兰和韦茅斯湾之间的避风区。
Many applications of risk assessment and Environmental Impact Assessments (EIA) require information about the local mesoscale climate at a very fine spatial scale. Current regional climate models (RCMs) with grid resolutions that normally range between 10 and 50 km cannot resolve the local physiographic features that influence the small‐scale features of local climate. This article presents a local climate model (LCM) system with an ultrahigh resolution and demonstrates its application to study the local climatology in a coastal zone where details of orography and coastline are important influences on the climate. The LCM has been developed from the Met Office Unified Model (MetUM) based on the concept of very high‐resolution numerical weather prediction. The ultrahigh‐resolution regional climate modelling is achieved through operating multiple nesting from a spatial resolution of 12 km down to ∼500 m. In this pilot study of the LCM, RCMs were run at 12, 4, 1.5 and 0.5 km grid resolutions to simulate the mesoscale climate of Weymouth Bay and Portland Harbour along the south coast of the United Kingdom. The period simulated was July‐August of the years 1993 to 2002, with model results validated against meteorological station time series. The results demonstrated the added value of the 500 m resolution model compared with the 1.5 km resolution model in modelling very fine local mesoscale climate patterns over the inner domain, including diurnal variations of temperature and winds, such as southwesterly flows, and the effect of wind channelling between the Isle of Portland and the mainland. Lower mean wind speeds are also found along the south‐facing coast to the east and in the shelter of Portland in the 500 m resolution model, particularly showing a sheltering zone between Portland and Weymouth Bay.