RegCM4.1对中国区域气候模拟能力评估

Evaluation on climate simulation ability of RegCM4.1 model over China

利用中国气象局提供的1985—2004年756个台站的逐日降水和气温观测数据评估了区域气候模式(Reg CM4.1)对中国地区不同季节的降水和气温的模拟性能,并结合中国的区域气候特征和气候带分布进行分区讨论。结果表明Reg CM4.1能够较好地再现中国地区四季降水占全年百分比、降水率的空间分布特点以及降水带南北摆动的季节变化特征。Reg CM4.1对平均气温分布模拟较好,强度和高低中心与观测事实接近,但对青藏高原地区的气温分布模拟值一致偏低。同时发现Reg CM4.1能够合理再现内陆地区气温日较差明显大于沿海地区的总体分布特征,不过模拟值在新疆和沿海地区比观测结果均偏低。

In order to give researchers valuable information in adopting RegCM4. 1 model（upgraded version of RegCM3） for climate simulations as well as improve RegCM4. 1 over China, the performance of RegCM4. 1 model in simulating precipitation and temperature for different seasons over China is evaluated by using 756 stations＇ daily precipitation and temperature observation data from China Meteorological Ad- ministration during 1985 to 2004 in this study. Meanwhile, the model performance in different sub-regions of China is also discussed by considering the regional climate characteristics and distribution of climatic zones. Results showed that RegCM4.1 model simulates the spatial distribution of the rainfall proportion in four seasons over China quite well and is able to reproduce the seasonal precipitation distribution and north-south migration of the rainfall belt. In addition, RegCM4.1 model better simulates the surface tem- perature except for cold bias over Tibetan Plateau. RegCM4.1 reasonably shows the overall distribution feature that diurnal temperature range over inland is larger than that over coastal regions, however, the simulation results ranging over Xinjiang and coastal regions are underestimated by the model.