[Influence of biomass burning in Central Asia on nitrate concentrations in Urumqi Glacier No. 1, eastern Tianshan Mountains, China].

Influence of biomass burning in Kazakhstan on nitrate concentrations in eastern Tianshan Mountains was studied. 52 samples of surface snow and snow pits were collected from Glacier No. 1 at the headwater of Urumqi River in eastern Tianshan Mountains, China. Nitrate concentrations in these samples were measured and atmospheric transmission was reconstructed with HYSPLIT air trajectory model. The objectives of this study were to identify the relationship between steppes fire and nitrate concentration in snow, and develop deposition process of nitrate caused by biomass burning in alpine glacier at high altitude. Results indicated that nitrate in surface snow could be regarded as a subsidiary indicator of biomass burning for long distance. Correlations for NO3- and K+ were 0.74 from mid September to late October 2002, which was obviously higher than mean concentration. It took 2-6 days from fire spots in Kazakhstan to sampling site. Whether the information in air mass with biomass burning products can be recorded or not, was mostly depend on local temperature and precipitation. Eluviation process was prominent at Glacier No. 1 in wet season, so postdepositional effect should be considered in paleoclimate reconstruction by ice core.