Climatic And Environmental Record In Chongce Ice Core, Qinghai-Tibet Plateau

Glacier is one of important sources of earth history,recording nature variation of climate and environment inhistorical period including the effect of modern human beingactivity on environment. The information in glaciers has manymerits as long time scale, highly precision, large information,and so on. Analyzing and dealing with the data ofδ¹⁸O, anionand cation by using the principle of glacier and statistics andunder the help of some software and by means of lately resultsof research, the paper tries to reestablish the variations ofclimate and environment in the studied areas for a historyperiod.After analyzing theδ¹⁸O in Changee Ice Core, we educe thatthe temperature in the area has a general upward trend withthree obvious waves: gradual upward stage in 1903～1940,downward stage in 1941～1970,upward stage in 1971～1992; Thefirst period has big wave, the second period is smooth, thethird period has the largest wave. At the same time, there isa positive correlation between the records of summertemperature in observatories around Taklimakan Desert and thedata of the ice core in a compatible period for 30-40 years from1950s to 1992. The trend of temperature variation in summer inthe front half century around raklimakan Desert has beenreestablished according to this. The temperature has a waveupward trend in a century scale, and the upward extent covered90 years in Summer in the desert is about 1.2℃.The mean value order of main cations from big to small inthe annual deposition for 90 years in Chongce ice core isCa²⁺＞Na⁺＞Mg²⁺＞K⁺. It has the same order as that in the crust. The analysis of the source of ion shows: the ions of Ca²⁺ and Mg²⁺are from the crustal materials. The crustal materials and saltlakes for ions of Na⁺,CI^-,SO₄^2-are the main contribution. Theion of NO₃^- originates from crustal materials and lightning andso forth. The analysis of the variation of ion content shows:the annual deposition of Ca²⁺,Na⁺,Mg²⁺ has a fluctuationdownward trend, while that of K⁺ has a fluctuation upward trend;and that of Cl^-, SO₄^2- has a fluctuation downward trend, theperiodical fluctuation variation between the two ions has thecomparative similar. But the fluctuation extent in thelate-term is smaller than that in the early-term andmedium-term in the twenty century, while the annual depositionof NO₃^- is on upward trend in the fluctuation variation.