天山乌鲁木齐河源1号冰川气溶胶可溶性离子昼夜变化研究

Day-Night Variations of the Soluble Ions in Aerosol on the Glacier No.1 in the Headwaters of the ürmqi River,Tianshan Mountains,China

在2007年4月16—23日,8月5—12日,10月20—23日3个采样时段内,分昼夜采集了16个气溶胶样品,对样品中的可溶性离子(Na+、K+、Mg2+、Ca2+、Cl-、NO3-、SO42-)进行了分析,以研究气溶胶可溶性离子的昼夜变化特征和可能的影响因素.结果表明:天山乌鲁木齐河源1号冰川气溶胶夜间平均离子浓度高于白天浓度,7种离子中,除NO3-在全年中的平均离子浓度表现为白天高于晚上外,其余离子的平均浓度均是夜间高于白天.区域风向的日变化是控制气溶胶浓度昼夜变化的主要影响因素,相比之下大气环流的影响则相对较弱.在所研究的8组昼夜变化事件中,Ca2+的昼夜变化最为明显,离子浓度的高值事件多出现在晚上,而其余离子在采样时段内的昼夜变化事件表现则不尽一致,无明显规律.

Day and night samples of aerosol （n = 16） had been collected on the Glacier No. 1 in the headwaters of the Urumqi River, Tianshan Mountains, during April 16 to 23, August 5 to 12 and October 20 to 23, 2007. All samples （including the species of Na^＋, K^＋, Mg^2＋, Ca^2＋, CI^-, NO3^- and SO4^2-） were analyzed and studied in terms of day-night variations. Results show that the nighttime samples generally have higher concentration than the daytime samples on the glacier.The nighttime samples have higher concentration than the daytime samples for Na^＋, K^＋, Mg^2＋, Ca^2＋, Cl^- and SO4^2-, except for NO3^-, which has higher concentration during daytime. The temporal variations of the concentrations during the sampiing periods were dominated by wind. In the eight day-night variation events, Ca^2＋ has obviously daynight variation, while the others varied with no regularity during the three sampling periods.