PRECIS模拟区域的选择对宁夏区域气候模拟效果的敏感性分析

Assessment of PRECIS Simulation Sensitivity to Domain Size over Ningxia

选定4种大小不同的模拟区域设置25km水平分辨率的PRECIS系统于宁夏地区,利用欧洲中期天气预报中心(ECWMF)1978年12月-1979年9月的再分析数据作为准观测边界条件驱动PRECIS,通过模拟的宁夏地区冬夏两季日平均气温和降水与观测资料的对比,分析25km水平分辨率气候模拟结果对模式区域选择的敏感性。结果表明:25km水平分辨率的PRECIS在4种不同模拟区域下都能较好地模拟宁夏地区典型年的日平均温度和降水量,尤其是对降水的模拟效果更好;总体上,PRECIS的模拟效果随着模拟区域的缩小而下降,但PRECIS在中小模拟区域下仍然能够获得较好的模拟效果。考虑到计算成本,本研究认为在中小模拟区域下25km水平分辨率的PRECIS能够较为高效地进行宁夏地区的气候模拟。

Ten month （December, 1978-September, 1979）ECWMF reanalysis data was employed as quasi-observational boundaries to drive PRECIS at 25km horizontal resolution over Ningxia to analyse the sensitivity of model simulation to 4 different domain sizes via comparing the simulated daily mean temperature and precipitation in summer and winter to with the observation. The results showed that the daily mean temperature and precipitation could be well simulated by PRECIS at 25km horizontal resolution over Ningxia in 4 kinds of different domain size, the PRECIS especially performed better for precipitation simulation. It can be seen that the PRECIS simulation was sensitive to the model domain size, the simulated results were declining when the domain size decreasing, however, the PRECIS simulation was still well in the mid-small domain size over Ningxia. Considering the expenses of calculation, the mid-small domain size was the most efficient to climate simulation in Ningxia using PRECIS at 25km horizontal resolution.