中国东部降水格局的未来数十至百年预估，需要加强多年代尺度上降水分布变化规律的认识。利用地球系统模式进行长时间瞬变模拟试验，是揭示其多年代变化特征及成因机制的有效手段。本课题拟采用先进的地球系统模式（CESM1.2），分别在全新世以来两个典型暖期（中全新世暖期和中世纪暖期）背景下 ，开展高分辨率长时间瞬变积分的气候模拟试验；在利用重建资料对模拟结果进行验证的基础上，根据高分辨率模拟结果分析中国东部降水在典型暖期的多年代变化特征，分析自然外强迫因子对中国东部降水的影响，分析多年代尺度上中国东部降水格局与大尺度环流异常及海温异常之间的关系，揭示不同暖期中国东部降水格局的多年代变化的成因机制。该研究对深入理解中国东部降水格局多时间尺度演变规律、区分自然和人为因子的气候效应、丰富和完善区域气候变化理论有重要的科学意义，对提高中国东部降水的预估能力、未来政策的制定及经济的发展具有重要的现实意义。

Understanding the multi-decadal variability of East China precipitation is crucial for predicting its future change in the next decades. The long term transient simulation with Earth System Model is an efficient method to reveal the spatial-temporal characteristics and the mechanisms of the multi-decadal variability of the East China precipitation. Using the state-of-the-art Earth System Model with high resolution (CESM1.2), two transient climate modeling experiments will be conducted for the two warms periods since the Holocene. One is forced by the combined Mid-Holocene forcing; another is forced by the combined Medieval Warm Period forcing. The forcings include the orbital variation, the solar variability, the volcanic aerosols, and the atmospheric trace gases. The modeling results will be verified by model-proxy data comparison. Based on the high resolution modeling results, analyses will be made to find out the leading modes of the multi-decadal variation of the East China precipitation. The effects of the natural forcings on the East China precipitation during the two warm periods will be explored. The relationship between the East China precipitation and the general circulations as well as the relationship between the East China precipitation and the sea surface temperature anomalies will be revealed. The mechanisms of the East China precipitation change on multi-decadal time scale during the warm periods will be understood. This research could have important scientific significance to improve in-depth understanding of the multi-scale variability of the East China precipitation, distinguishing the climatic impacts of natural and anthropogenic forcings, and enriching the regional climate change theory. It could also have great practical significance for improving the projection ability of the East China precipitation, the policy making and promoting the economic development.