%0 Journal Article
%T RECONSTRUCTION OF EARLY-SUMMER DROUGHT INDICES IN MID-NORTH REGION OF CHINA AFTER 1500 USING TREE RING CHRONOLOGIES<br>中国陕西关中及周边地区近500年来初夏干燥指数序列的重建
%A 刘洪滨
%A 邵雪梅
%A 黄磊
%J 第四纪研究
%D 2002
%I 
%X The climatic condition of the mid north region of China is semi arid and trees grow in this region are sensitive to the temperature of late spring and the precipitation of early summer. The early summer drought indices are calculated based on the precipitation and temperature in May and June and well represented the climatic condition of the key period for tree′s growth.In this study we used three ring width chronologies of Huashan Pine sampled in west, east and south peaks of Huashan Mts. to reconstruct the early summer drought indices series in mid north region of China from 1500 to 1992.The early summer drought indices have a higher correlation coefficient in a wide region of Guanzhong Plain of Shaanxi Province and the highest value of correlation coefficient is 0.96. The reconstructed series were analyzed with statistical methods and further correlated with the large scale atmospheric circulation. The chronologies of Huashan Pine were well consistent with the early summer drought indices in the last several decades and can be used in the indices reconstruction. The fluctuation of the early summer drought indices was significant during 1500 and 1600 as well as after 1800. The fluctuation of the drought indices was out obvious for the period from 1700 to 1800. Three severe drying periods are found in this region in the past 500 years, which are 1502 to 1511, 1570 to 1580 and 1807 to 1814. Thirteen years and four years period cycles are found significant in the reconstructed series, but the periodic statistical characteristics are different among each time periods. The wavelet analysis was used to analyze the structure of period cycles of the reconstructed summer drought indices series. The abrupt change of average value in 1587 and the abrupt change of standard deviation in 1944 were found in the reconstructed series.The drought indices in May and June have a high correlation coefficient with the strength of polar eddy in North Hemisphere a few months before. A stronger polar eddy indicated a more arid climatic condition of the mid north region of China.
%K climate change
%K tree ring
%K Huashan Pine
%K drought indices<br>中国
%K 陕西
%K 气候变化
%K 树轮
%K 华山松
%K 干燥指数
%K 冷空气活动
%K 古气候
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=E62459D214FD64A3C8082E4ED1ABABED5711027BBBDDD35B&cid=621CF755B1A341E5&jid=EA07051745CDC8D89D5F01A3A4CFE6A9&aid=A7CD01F81DB0BEB3&yid=C3ACC247184A22C1&vid=BC12EA701C895178&iid=38B194292C032A66&sid=1D67BE204FBF4800&eid=F8035C8B7D8A4264&journal_id=1001-7410&journal_name=第四纪研究&referenced_num=32&reference_num=17