中文摘要：

利用通用地球系统模式CESM的过去2000年气候模拟试验资料，在与历史气候重建资料、观测/再分析资料及其他模式模拟资料进行对比验证的基础上，分析了中国中世纪暖期（Medieval Warm Period，简称MWP）地表温度年代际变化特征并初步探讨了其成因。结果表明：在公元801~1250年的中国中世纪暖期期间，在年代际尺度上，中国地表温度EOF第一模态的空间分布为全区一致型，并且北部的变率大于南部，最大的变率中心位于中国东北部；EOF第二模态反映出研究区内南北反向的空间分布特征。40°N以北地区温度变化一致；40°N以南青藏高原-云贵高原-东南沿海地区与华北地区呈反相变化，最大的变率中心位于青藏高原东部。中世纪暖期地表温度EOF第一模态主要归因于太阳辐射的影响，火山活动也是影响因子之一；EOF第二模态主要受气候系统内部变率的影响，其他外强迫因子的影响较小。但是，温室气体、土地利用/覆盖两个外强迫因子对气候系统内部变率具有一定的调制作用。在中国，中世纪暖期太阳活动剧烈、火山活动较少，下垫面吸收更多的太阳短波辐射，地表净辐射通量增大，是中世纪暖期形成的主要原因。

英文摘要：

The characteristics and causes of interdecadal temperature changes over China during the Medieval Warm Period（MWP）are analyzed in this paper, based on the climate simulation results over the past 2000 years using the Community Earth System Model（CESM）. By comparing with proxy records, observational/reanalysis datasets and other simulation results, CESM is proved to be reasonable in simulating the temperature variation of China. The results from 8 climatic experiments are analyzed, including total solar irradiation experiment（TSI）, volcanic eruption experiment（Vol）, greenhouse gas experiment（GHGs）, land use and land cover change experiment（LUCC）, control experiment（Ctrl）, all forcing experiment（ALL）, anthropogenic forcing experiment（ANTH）and natural forcing experiment（SV）. These experiments are carried out from 1A.D.to 2000 A. D except the volcanic eruption experiment, which simulates the climate variation from 501A.D.to 2000A.D., limited by the reconstruction of the volcanic forcing. Though the past 2500 volcanic forcing was reconstructed by Sigl et al.in 2015, it is later then the time we begun those experiments. The simulated time series of annual mean surface temperature anomaly（℃, relative to 501~2000A.D.）over China show that, the MWP is from 801 A.D.to 1250 A.D.in China. The method of the empirical orthogonal function（EOF）is used to study the characteristics of the temperature change in this paper. 7-year running mean datasets are used to highlight the interdecadal variabllity. The results show that the first EOF mode of 7-year running mean temperature variation is dominated by an uniform sign pattern during the MWP over China from all forcing experiment. The variability ratios increase from south to north in the research area. The maximum variability center located at the northeast of China. The second EOF mode is a north-south dipole pattern. The temperature change is out-of-phase between north and south of 40°N in the research area, and it is out-of-phase