DUST STORM EVENTS AND THEIR RELATION TO CLIMATE CHANGES IN NORTHERN CHINA DURING THE PAST 2000 YEARS
中国北方过去2000年沙尘事件与气候变化*

According to the "Climate Regionalization Map of China" compiled by China Meteorological Administration in 1978, and fuzzy cluster zoning by Xu, et al., we divided the research area into three sub-areas, the western arid region, the eastern arid region, and the semiarid region. Dust storm events and their relation to climate changes in North China during the past 2000 years were analyzed by using paleoclimate proxies, such as ice cores, tree rings, and historical documents. Dust storm events over the last 2000 years reflected by Ca2+ and Mg2+ contents recorded in the Guliya ice-core and microparticle concentration in the Dunde ice-core as well as dust storm events recorded in historical documents of China are compared with ice accumulation rates, δ18 O, tree-ring width, and multi-proxy reconstructed temperature and precipitation sequences. We tried to quantify the contribution of temperature and precipitation to dust storm occurrences in different regions, to probe into the dust storm formation mechanism and develop a model of climate changes and dust storm events.The results show that in the western arid region at both the decade timescale and the century timescale, the dust storm changes were mainly controlled by temperature changes during the past 2000 years and the dust storm events and temperature changes exhibite a significant negative correlation. In other words, the dust storm events were more frequent under cold climate than under warm climate. In the semiarid region, temperature and precipitation sequences were both significantly negatively correlated to dust storm at decade timescale. At century timescale however, precipitation changes have a closer correlation with dust storm events than temperature. In the eastern arid region, the relationship between dust storm events and climate changes displayed obvious transitional features, and the effects of climate changes on dust storm events were mainly manifested at century timescale. The negative correlation between temperature and dust storms was more obvious than that of precipitation and dust storms. On the other hand, although the climate and the dust storm sequences were also negatively correlation at decadal timescale, such negative correlation was not significant. Analysis of modern meteorological records over the last 50 years came to the roughly same conclusion.