Chemical composition of aerosol and fresh snow and tourism influences at Baishui Glacier No. 1 from Mt. Yulong, Southeastern Tibetan Plateau

Abstract

Aerosol and snow samples were collected at ablation zone of Baishui (sic) Glacier No. 1, Mt. Yulong (sic), from May to June, 2006. The concentrations of Cl(-), NO(3)(-), SO(4)(2-), Na(+), K(+), Mg(2+), and Ca(2+) were determined by ion chromatograph both in aerosol and snow samples. The average total aerosol loading is 25.45 neq.scm(-1), NO(3)(-) and Na(+) are the dominant soluble ions in the aerosol, accounting for 39% and 21% of average total aerosol loading, respectively. Monsoon circulation reduces the concentration of most ions, indicating that wet scavenging is effective for aerosol particles. In snow samples, SO(4)(2-) and Ca(2+) are the dominant anion and cation, respectively. A lower Na(+)/Cl(-) ratio was found in fresh snow samples compared to the higher ratio that was found in aerosol samples. Analyzing the difference in SO(4)(2-) and NO(3)(-) in air and fresh snow indicated that the aerosol was influenced by local circulation, but the components in fresh snow samples were from long-distance transport. Enrichment of NO(3)(-) in aerosol samples is attributed to motor exhaust emissions from tourism by calculating the SO(4)(2-)/NO(3)(-) ratio in aerosol and fresh snow samples. The temporal variation and correlation coefficients between soluble species in aerosol samples suggest that Cl(-), Na(+) and K(+) come from sea-salt aerosol, and SO(4)(2-), Mg(2+) and Ca(2+) are from continental crust sources.