Acta Geographica Sinica ›› 2017, Vol. 72 ›› Issue (3): 382-396.

• Climate Change and Surface Processes •

Temperature variations evidenced by records on the latest spring snowing dates in Hangzhou of eastern China during 1131-1270 AD

Haolong LIU1(), Junhu DAI1, Junhui YAN2, Fanneng HE1, Quansheng GE1(), Chongxing MU3

1. 1. Key Laboratory of Land Surface Pattern and Simulation, Institute of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China
2. The College of Urban and Environmental Sciences, Xinyang Normal University, Xinyang 464000, Henan, China
3. The Taizhou Meteorological Bureau, Taizhou 318000, Zhejiang, China
• Received:2016-09-28 Revised:2016-11-28 Online:2017-03-15 Published:2017-03-15
• Supported by:
National Natural Science Foundation of China, No.41427805;Basic Research Project of the Ministry of Science and Technology, No.2014FY210900, No.2011FY120300

Abstract:

We collected and verified documentary records of the latest spring snowing dates (LSSD) in Hangzhou during the Southern Song Dynasty. Further, the statistical correlation between this proxy and February-April mean temperature in this region was examined, and samples later than the perennial mean of the LSSD during the study period were transformed into the decadal mean of LSSD by means of Boltzmann function. General characteristics of this reconstructed LSSD series with a 10-year temporal resolution were analyzed, compared with other documentary evidences and reconstructed climate series in China for 1131-1270 AD. The results suggested that: (1) Records of the LSSD in Hangzhou during the study period did not refer to ice pellets and graupels, which had an explicit climatic significance (-0.34 oC/10d, R2=0.37, P<0.001). However, when this proxy was used to reconstruct temperature changes, all dates should be converted in Gregorian style and meet the same criterion of "true Qi" as the Chinese traditional calendar after 1929 AD. (2) The decadal mean of LSSD can be effectively estimated by using the forefront of LSSD in the decade on the basis of Boltzmann function, whose extrapolation has a less uncertainty than that on the basis of linear models or polynomial models. (3) The spring in Hangzhou during 1131-1270 AD was almost as warm as the period 1951-1980 AD. At the centennial scale, this period can be divided into two phases: the cold 1131-1170 AD and the warm 1171-1270 AD. In the latter, 1181-1200 AD and 1221-1240 AD were two cold intervals at the multi-decadal scale. (4) The reconstructed LSSD series was well consistent with other documentary evidences and reconstructed climate series in China for 1131-1270 AD, which may reflect the mutual influence on the climate over most of China imposed by the Pacific Decadal Oscillation (PDO).