To assess the seasonality of aerosol deposition and anthropogenic eects on central Himalayas, a 1.85-m deep snow pit was dug on the northern slope of Mt. Qomolangma (Everest). Based on the morphology and energy dispersive X-ray (EDX) signal, totally 1500 particles were classed into 7 groups: soot; aluminosilicates; y ash; calcium sulfates; Ca/Mg carbonates; metal oxides; and biological particles and carbon fragments. The size distribution and number fractions of dierent particle groups exhibited distinct seasonal variations between non-monsoon and monsoon periods, which are clearly related to the dierences in air mass pathways. Specifically, the relative abundance of soot in non-monsoon period (25%) was much higher than that in monsoon period (14%), indicating Mt. Qomolangma region received more anthropogenic inuence in non-monsoon than monsoon period.
Thirty samples of total suspended particles were collected at a site in western part of Lhasa,Tibet from August 2006 to July 2007.The 10Be concentrations were determined by Accelerator Mass Spectrometer (AMS).Analysis of correlation between 10Be concentrations and meteorological factors revealed that the wet scavenging has little effect on 10Be.10Be can be used as a proxy of transport processes of the upper atmosphere over the Tibetan Plateau.Analysis of correlation between 10Be concentrations and NCEP reanalysis data demonstrated that higher 10Be concentrations in spring were probably caused by the atmosphere exchange from stratosphere to troposphere during February to June.Lower 10Be concentrations during August to September were consistent with the synchronous lower O3 values,suggestive of both 10Be and O3 were probably influenced by the atmosphere exchange from troposphere to stratosphere.
