Decadal Climatic Variations Recorded in Guliya Ice Core and Comparison with the Historical Documentary Data from East China During the Last 2000 Years

【摘要】：正 The high-resolution records of δ~(18) O and snow accumulation variations from the Guliyaice core provides valuabe data for research on climatic variations at a decadal resolution duringthe past 2000 years in China.Based on the ice core data,five spells have been divided:the warmand wet period before 270 AD,the cold and dry period between 280 and 970 A.D,the moderateand dry period between 970 and 1510 A.D,the well-defined“Little Ice Age”with drastic cold-warm fluctuations between 1510 and 1930 A.D and the warming period since 1930 AD.According to the combination of temperature and precipitation,cold events(55 times) surpasswarm ones(26 times),and dry events(55 times) surpass wet ones (45 times).Cold-wet events(14times)are less than cold-dry ones(16 times),while warm-wet events(10 times) are more thanwarm-dry ones (4 times).If the difference.of 2‰ in δ~(18) O (corresponding to 3K in temperature)between two or three adjacent decades is taken as the criterion of it,the abrupt change has takenplace 33 times or so since the third century.Among them are four large ones,occurred in 250-280,550-580,1220-1260,and 1520-1560 AD respectively.Comparison of the ice core data with thelatest comprehensive research results on historical documents of East China shows that the greatclimatic events appeared simultaneously or at the same age in the ice core record and in thedocumentary data,suggesting the consistences and similarities in climatic variation amongdifferent areas far away each other in the lower to mid-latitudes.However,there is a greatdifference between them during the Medieval Warm Feriod,which is conspicuous in the historicaldocuments but not in the ice core.In addition,the first cold event of the Little Ice Age on easternChina was 60 years earlier than that of the Guliya Ice Cap,when the degree of cooling in WestChina is more intensive than that of East China.But the third cold event occurred in East Chinalags behind that in West China during the late 19th century.The 1820s cold event both in West andEast China may be driven by the magnificent Tambora volcanic eruption in 1815.