CSIRO Mk3.6.0模式及其驱动下RegCM4.4模式对中国气候变化的预估

使用区域气候模式RegCM4.4，对全球模式CSIRO-Mk3.6.0在RCP4.5情景下的气候变化试验结果（1950-2100年）在东亚地区进行25 km动力降尺度试验，比较了CSIRO-Mk3.6.0和RegCM4.4预估中国地区的21世纪气候变化。结果表明，两个模式预估未来中国地区气温持续升高，升温幅度具有区域性特征，RegCM4.4预估区域平均升温幅度低于CSIRO-Mk3.6.0，但二者年际波动基本一致。两个模式预估未来降水在中国西部以持续增加为主，东部则表现出较大的不一致性，预估区域平均年降水量变化不大，呈现冬季明显增加，夏季微弱减少的特点。此外，为了解区域气候模式对中国降水预估的不确定性，对本研究和以往RegCM3使用相同分辨率模拟得到的未来降水预估进行了对比，两个区域模式预估中国西部大部分地区未来降水一致性增加，东部存在明显不一致（冬季中、高纬除外）。

Comparison of Climate Projection Between the Driving CSIRO-Mk3.6.0 and the Downscaling Simulation of RegCM4.4 over China

A 151-year (1950-2100) dynamical downscaling simulation over East Asia is conducted by using the regional climate model RegCM4.4 at 25 km grid spacing, which is nested within CSIRO-Mk3.6.0. Climate changes over China during the 21st century under the RCP4.5 scenario from CSIRO-Mk3.6.0 and RegCM4.4 are analyzed. Both simulations project that continuous warming with large regional variations will occur in the future. The two simulations obtain similar inter-annual fluctuations of regional average warming, with RegCM4.4 obtaining somewhat smaller values than CSIRO-Mk3.6.0. Projected precipitation changes are even more regionally variable than temperature changes. In western China, both models project increased precipitation, while the projections from two models show different regional details in eastern China. In both simulations, projected annual mean precipitation on national scale does not change significantly due to the contrast changes between dry and wet seasons. To analyze uncertainties of the projected climate change in China, the simulation of RegCM4.4 is compared with a previous simulation of the RegCM3 at the same horizontal resolution. The overall consistency in precipitation change between RegCM3 and RegCM4.4 is projected across western China, while inconsistency is identified in most of eastern China.