近千年东亚夏季风演变历史重建及与区域温湿变化关系的讨论

集成中国季风区石笋氧同位素记录的共同变化特征，初步建立了近千年10年平均的东亚夏季风演变序列。在10年尺度以上分析了东亚夏季风演变与其他气候要素变化之间的关系。主要结论有： 1)近千年来东亚夏季风演变可划分为中世纪时期(11～13世纪初期)的季风稍弱阶段，13世纪中后期至14世纪前半叶的季风较强时期，14世纪后半叶至17世纪的季风较弱阶段，自18世纪开始持续约200年的季风再次增强时期，以及20世纪初开始的季风逐渐减弱阶段。2)近千年来东亚大陆或北半球温度的变化虽然对东亚夏季风变化具有一定的影响，但东亚夏季风强度的变化并不总是取决于陆地温度的变化。3)近千年来东亚夏季风的强弱变化与降水变化在低频趋势上有良好的对应关系，在东亚夏季风增强的时期，中国东部降水较多，而在夏季风减弱时，中国东部降水趋于偏少。

VARIABILITY OF THE EAST ASIAN SUMMER MONSOON AND ITS RELATIONSHIP WITH REGIONAL TEMPERATURE AND MOITURE CHANGE DURING THE LAST MILLENNIUM

A large number of temperature and precipitation reconstructions of the Northern Hemisphere and China which span the past millennium have been established. The reconstructions provide an important insight for understanding and assessing present climate change from the historical perspective. However，the knowledge of variability of East Asian summer monsoon(EASM)on decadal to centennial timescales is still scarce due to shortness of instrumental measurements and lack of the EASM proxy reconstructions of the last 1000 years，although the EASM and its associated atmospheric circulations cause large and direct impacts on economy，society，and the natural environment in East Asia，especially in the eastern part of China. The reconstruction of the EASM lasting centuries and millennium is of great importance for bridging the gap of the relationship between the EASM and temperature/precipitation changes on decadal，interdecadal and centennial timescales. The establishment of well­dated and continuous high­resolution millennium­long stalagmite oxygen isotope sequences derived from different regions of East Asian monsoon area and the new knowledge of climatic signals of stalagmite oxygen isotope records offer the possibility for reconstructing the EASM series extending back to the last 1000 years. In this paper，we first studied temperature variations in China during the last millennium based on former reconstructions and coupled ocean­atmosphere model simulated results，and illustrated general characteristics of precipitation variations and regional similarities and differences in monsoon area of China by the use of historical document­based precipitation reconstructions. Then，we made a preliminary decadal­scale EASM reconstruction covering the last millennium by combining four high­resolution stalagmite oxygen isotope series derived from northern and southern parts of East Asian monsoon area. Finally we made a discussion on the relationship between the EASM and regional climate(temperature and precipitation)change in the context of the last millennium. It is found that the EASM experienced weak monsoon period during the middle ages(11­the early 13th century)，an intensified monsoon interval from the middle­late 13th century to the first half of the 14th century，a generally weak monsoon stage with alternating stronger and weaker monsoon fluctuations between the second half of the 14th century and the 17th century，a return to strong monsoon conditions from A．D.1700 to the beginning of the 20th century which lasts 200 years in length，and the present gradual weakening stage during the 20th century during the last millennium. The East Asian mainland or Northern Hemisphere temperature changes have certain influence on the EASM change，but intensity change of the EASM is not always determined by the mainland temperature change during the last millennium. The EASM has good correspondence with precipitation change in low­frequency domain，particularly in the prominent peaks and troughs. When the EASM strengthens，precipitation in monsoon area is abundant，but precipitation amount tends to be low when the EASM weakens.