基于区域气候模式CCLM的中国极端降水事件预估

选用中国气象局国家气候中心由逐日观测资料插值而成的格点化观测数据集,评估了区域气候模式COSMO-CLM(CCLM)对中国极端降水的模拟能力,并对2016—2050年中国极端降水事件进行预估。文中主要采用强度-面积-持续时间(Intensity-Area-Duration,IAD)方法,识别了既定时间尺度下具有一定强度和影响面积的极端降水事件,分析未来中国极端降水事件的特征和变化趋势,结果表明:1)区域气候模式CCLM对中国极端降水的空间分布和变化趋势均有较强的模拟能力;2)2016—2050年中国极端降水事件整体呈增加趋势,RCP 8.5情景下变化更为显著,事件强度更大;3)未来不同情景下,均有可能发生强度或影响面积超过基准期最大值的事件,其中影响面积大的事件多发生在华北和东北,强度大的事件多发生在西南和华南。

JING Cheng1, TAO Hui3, WANG Yan-jun1, SU Bu-da1,2,3, HUANG Jin-long3, JIANG Tong1,2

A gridded observation data set interpolated with daily observation data by the National Climate Center is selected to evaluate the capability of a regional climate model COSMO-CLM（CCLM）for simulating extreme precipitation in China. The paper mainly applies the Intensity-Area-Duration (IAD) method to identify the extreme precipitation events with certain intensity in certain area at the given time scale, and project the trend of extreme precipitation events in the future (2016-2050) based on the CCLM output. The research results show that: 1) CCLM can well capture the distribution and trend of the extreme precipitation in China. 2) The extreme precipitation events in China will increase during 2016-2050. The increasing trend is more significant and the events are more intensive in RCP 8.5 scenario than in RCP 2.6 and RCP 4.5. 3) Extreme precipitation events beyond the maximum intensity/coverage of baseline period are likely to occur in all emission scenarios during 2016-2050. The events with larger area will mainly distribute in North China and Northeast China. The events with higher intensity will mainly distribute in Southwest China and South China.