DOI: 10.25921/8x99-ea91
title: NOAA/WDS Paleoclimatology - Climate in China during the Little Ice Age

description: Usually, 1550-1850, while the climate was relatively cold, was called as the Little Ice Age. 30-year mean temperature in the coddle latitude of the Northern Hemisphere during the Little Ice Age was generally 1.0°C lower than the observed in the coddle and late present century. Lowering of temperature increased to 1.5-2.0°C in the higher latitudes in the Southern Hemisphere. Zhu had indicated in 1973 that cold winters in China were concentrated in three Periods; 1470-1520, 1620-1720, and 1840-1890, though he did not use the terminology of the Little Ice Age. Wang had reconstructed in 1990 decadal mean seasonal temperature anomalies of North and East China for the period of 1470's to 1980's. It provided at the firstbine an opportunity to examine the Little Ice Age in China based on a homogeneous temperature series. Wang et al. (1990) then identified three cold periods, which had been denoted as I, II, and III. Moreover, two colder stages were found in each of the cold periods, which were indicated as foot note 1 or 2. The cold stages in China were as follows: 
I. 1 1450's-1470's, or I. 2 1490's-1510's, 
II. 1 1560's-1600's, II. 2 1620's- 1690's, 
III. 1 1790's-1810's and III. 2 1830' s-1890's. 
Recently, annual temperature series of 1880-1996 were constructed for each often regions of China, which covered whole territory of China, including Tibet and Taiwan. It provided good bases for reconstruction of temperature series for the last 500 to 1000 years. In the following, data sources used in reconstruction were outlined from region to region. 
(1) Northeast. Tree-ring data was used to reconstruct annual temperature between 1748 to 1880 (Wei Sonlin personal communication). New tree-ring data of ShaoXuemei was used for the period 1600 to 1748. 
(2) North. Decadal mean temperature anomaly series were used, which were reconstructed by Wang on the basis of documentary data. 
(3) East The same as used for North. 
(4) South. Decadal mean temperature anomaly series were reconstructed recently by using of the same method as for the North and East China. 
(5) Taiwan. The same as for South. 
(6) Central-South. Decadal mean temperature series were reconstructed by YeYuyuan et al. (Personal communication ) on the basis of documentary data.
(7) Southwest. The same as used for South. 
(8) Northwest. Ice core δ18O data in Dunde were used. 
(9) Xinjiang. Ice core δ18O data in Guliya were used. 
(10) Tibet. Tree-ring data of Kang Xingcheng were used. Decadal means of temperature are used in present study, for the limit of the resolution of proxy data. 
Firstly, all kinds of the proxy dare are normalized, and then the regional standard deviation of decadal mean temperature is multiplied, which was calculated by using of observatory data of 1961-1990. It insures the homogeneity of the series. Finally, regional decadal-mean temperature anomaly series are obtained. However, the length of the series varies from region to region. The longest series available now are that for Xinjiang, Northwest and Tibet. Historical documents allow to reconstruct the series only since 1380 to 1470, for the scarce of dare in early time. However, this is the first time one can examine the Little Ice Age in the whole territory of China. Main results are as following:
(1) To establish the series of China, regional temperature anomalies are averaged with the weighting factors, which are proportional to the size of the region.
(2) All of the regional series positively correlate to the series of China.Maximum correlation coefficients are found between Northwest Tibet on the one hand and National on the others.
(3) Ten regions can be divided into three groups: 
1) Mainland areal, including North, Ease Northwest and Tibet. 
2) South territory, including South, Central-South and Southwest. 
3) Surrounding area including Xinjiang and Northeast.
(4) Five cold periods are identified for the last millennium; 1100's- 1150' s, 1300' s- 1390' s, 1450' s- 1510' s, 1560' s- 1690's and 1790' s- 1890' s.
However, temperature anomaly varied from region to region in each of the cold periods.
description: Elevation estimated from GoogleEarth; rounded to 100 m