Information About Low Cloud Amount Recorded in δ^13C Series of Tree Ring Cellulose of Pinus Koraiensis in Antu Area,Jilin

Relationship between the δ^13C of tree ring cellulose from Pinus Koraiensis and climate parameters was investigated.A significantly negative correlation between δ^13C and mean low-cloud amount from May to July was discovered,which contributes to reconstructing the mean low-cloud amount form May to July at Antu in recent 200years.Periodicals of quasi-8-year,quasi-4-year and quasi-2-year were detected both in δ^13 C series and in the reconstructed low cloud amount series with 95% confidence level.Quasi-8-year period may reflect the integrated influence of solar activity,monsoon activity and local regional factors.Quasi-4-year and quasi-2-year periods indicate the influences of ENSO and Qussi Biennial Oscillation(QBO)of East Asian monsoon,respectively.