出版社：Chinese Association for Aerosol Research in Taiwan
摘要：The present study was carried out to understand the snow chemistry with special emphasis on the estimation of wet deposition fluxes and transportation of ionic species to the Himalayan regions from December 2015 to March 2017. All the snow samples were collected from three different sites of two locations, JammuandKashmir and Himachal Pradesh. In Jammu and Kashmir we have selected two sites, (an urban area Leh and other one was semi-urban area Beerwah). In Himachal Pradesh, we selected a site at Nirmand village which was a rural area. At Leh and Nirmand village, samples were showing higher alkalinity than at Beerwah site. The pH values of snow at Leh and Nirmand were recorded above 5.6 except one sample of both the sites. However, at Beerwah site almost 60% of the samples were found acidic (below 5.6) in nature. All these three sites showed three different means of neutralization and pH control. The study revealed that the high pH value of snowfall at Leh site could be due to the presence very high value of Ca2+ whereas the moderate pH at Nirmand village may be due to moderate concentration of Ca2+ and high NH4+. In contrast at Beerwah site, low pH is probably due to very low concentrations of all the major cations. This study also suggested that non-sea salt sources contributed a significant fraction of SO42–, K+, Ca2+, and Mg2+. However, on average, a significant amount of HCO3– was measured at all the three sites, indicating a substantial role of crustal sources in the study sites. Results of this study showed that these ionic species are contributed by local as well as long-distance sources in the region. Backward airmass trajectory analysis revealed that the ionic species were contributed by the airmasses coming from North Atlantic Ocean, Africa, Europe, Middle East, and Mediterranean region to all these sites through long-range transport (LRT).
关键词：Snow; pH; Ionic chemistry; Wet deposition flux; Back trajectory analysis.
