Using historical records on first and last frost and snow,spring cultivation,David peach blossom,autumn crop harvest,grade of sea freeze and change in northern citrus boundary,we reconstructed temperature change durin...Using historical records on first and last frost and snow,spring cultivation,David peach blossom,autumn crop harvest,grade of sea freeze and change in northern citrus boundary,we reconstructed temperature change during 601-920 AD.The mean temperature of the winter half-year(October to April)over Central East China during this period was about-0.22°C higher than that of the present(1961-2000 AD mean).During 601-820 AD,mean temperature was about-0.52°C higher than the present.During 821-920 AD,the mean temperature was 0.42°C lower than the present.The temperature fluctuations were characterized by a maximum amplitude of 1.05°C at the centennial scale,1.38°C at the 50-year scale,2.02°C at the 30-year scale,and 2.3°C at the 20-year scale.There were four peaks warmer than today(601-620 AD,mean of 1°C higher temperature;641-660 AD,1.44°C;701-720 AD,0.88°C;781-800 AD,0.65°C).Three cold periods were in 741-760,821-840,and 881-900 AD,the mean temperature of which was 0.37-0.87°C lower than the present.展开更多
基金supported by the Knowledge Innovation Program of the Chinese Academy of Sciences(KZCX2-YW-Q1-01and KZCX2-YW-315)the National Natural Science Foundation of China(40625002)
文摘Using historical records on first and last frost and snow,spring cultivation,David peach blossom,autumn crop harvest,grade of sea freeze and change in northern citrus boundary,we reconstructed temperature change during 601-920 AD.The mean temperature of the winter half-year(October to April)over Central East China during this period was about-0.22°C higher than that of the present(1961-2000 AD mean).During 601-820 AD,mean temperature was about-0.52°C higher than the present.During 821-920 AD,the mean temperature was 0.42°C lower than the present.The temperature fluctuations were characterized by a maximum amplitude of 1.05°C at the centennial scale,1.38°C at the 50-year scale,2.02°C at the 30-year scale,and 2.3°C at the 20-year scale.There were four peaks warmer than today(601-620 AD,mean of 1°C higher temperature;641-660 AD,1.44°C;701-720 AD,0.88°C;781-800 AD,0.65°C).Three cold periods were in 741-760,821-840,and 881-900 AD,the mean temperature of which was 0.37-0.87°C lower than the present.