利用1961年-2010年天山地区21站的冬季降雪资料,采用线性倾向估计法、反距离加权法和Morlet小波分析等方法,研究了天山地区近50a冬季降雪量及降雪的集中度与集中期的时空变化特征,并在此基础上应用Rescaled Range Analysis分析方法尝试预测了未来该地区冬季降雪量变化的情形。结果表明:天山地区冬季降雪量呈明显上升趋势,未来天山地区冬季降雪量的变化趋势与过去50a冬季降雪量的变化趋势相同,仍将持续上升,冬季降雪的集中度和集中期也呈上升趋势,但空间差异明显;冬季降雪量及降雪的集中度和集中期在一定的时间序列中存在不同周期变化,且周期反映比较明显;此外研究还发现,天山地区南(北)坡冬季降雪量及降雪的集中度和集中期的年际变化也不尽相同。
Aerosol samples were collected in the Shiyi Glacier, Qilian Mountains from July 24 to August 19, 2012 and analyzed for major water-soluble ionic species(F^-, Cl^-, NO_2^-, NO_3^-, SO_4^(2-), Na^+, NH_4^+, K^+, Mg^(2+) and Ca^(2+)) by ion chromatography. SO_4^(2-) and NH_4^+ were the most abundant components of all the anions and cations, with average concentrations of 94.72 and 54.26 neq/m^3, respectively, accounting for 34% and 20% of the total water-soluble ions analyzed. These mean ion concentrations were generally comparable with the background conditions in remote sites of the Qilian Mountains, but were much lower than those in certain cities in China. The particles were grouped into two dominant types according to their morphology and EDX signal: Si-rich particles and Fe-rich particles. Backward air mass trajectory analysis suggested that inland cities may contribute some anthropogenic pollution to this glacier, while the arid and semi-arid regions of central Asia were the primary sources of the mineral particles.
