Acta Geographica Sinica ›› 2019, Vol. 74 ›› Issue (7): 1281-1291.doi: 10.11821/dlxb201907001

• Climate Change and Surface Processes •     Next Articles

Evidences and regional differences on multi-scales in Medieval Climate Anomaly over China

ZHENG Jingyun1,2,LIU Yang1,2,WU Maowei1,2,ZHANG Xuezhen1,2,HAO Zhixin1,2()   

  1. 1.Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
    2.University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2018-11-21 Revised:2019-04-17 Online:2019-07-25 Published:2019-07-23
  • Contact: HAO Zhixin E-mail:haozx@igsnrr.ac.cn
  • Supported by:
    National Natural Science Foundation of China(41671036);National Natural Science Foundation of China(41831174);Chinese Academy of Sciences(XDA19040101)

Abstract:

Medieval Climate Anomaly (MCA, 950-1250 A.D.) was the most recent and lasting hundreds of years warm period, which has aroused more attention from climate scholars, because MCA provided similar patterns to research on the impact and adaption of global and regional warming. In this study, we investigate the characteristics of temperature variation on inter-decadal to centennial scale during MCA in four regions (including Northeast, Northwest, Central-east and Tibetan Plateau) in China based on high-resolution temperature reconstructions longer than 1000 years and related warm-cold records from historical documents. Ensemble empirical mode decomposition method is used to analyze the cycles and fluctuations of four regional temperature series. The results show that the longest warm period during the last 2000 years occurred in the 10th-13th centuries over the whole country, although there existed several cold decadal intervals in the mid to late 12th century, different starting-ending warming periods and warming magnitudes in four regions. On quasi-30-year scale, regional temperature variations were similar during 950-1130 A.D. while their amplitudes became smaller and the phases did not match well each other in 1130-1250 A.D. On centennial scale, all the four regions began a warm period in the early 10th century and experienced two cold intervals during MCA. However, temperature variations of Northwest and Central-east kept in phase each other, but out phase in Northeast and Tibetan Plateau, where the ending of the warm period was earlier about 40-50 years than that of Northwest and Central-east. On multi-centennial scale, the mean temperature difference between MCA and Little Ice Age in Northeast and Central-east is significant, but did not appear in Northwest and Tibetan Plateau. Compared with the mean temperature of the 20th century, Central-east had a comparable warming level, Northeast was a little cooler, and both Northwest and Tibetan Plateau had significantly lower temperatures in MCA.

Key words: Medieval Climate Anomaly, temperature, mlulti-scale, regional differences, China