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A 16.8 m firn core of middle Himalayas was recovered on the col of Dasuopu glacier in August 2006,being 7000 m above sea level.A total of 317 samples were measured for stable oxygen isotope ratios(δ18O)and major ion concentrations(Na+,NH4+,K+,Mg2+,Ca2+,Cl?,SO42?,and NO3?).The firn core dating and seasonal partitioning were carried out based on the marked seasonal variations along the stable oxygen isotopes and crustal species(Ca2+,Mg2+)profiles.The multi-parameters and high-resolution glaciochemical data set of Dasuopu firn core recorded the detailed chemical characteristics of pre-cipitation in high-elevation region,middle Himalayas,since 1991 A.D.,which mainly originated from the crustal and anthropogenic sources,while the sea-salt contribution was minor.The seasonal variability of major ion concentrations was dominated by the seasonal alternation of the prevalent air mass,at-mospheric circulation situation and precipitation regime.Linear regression analysis indicated that most of the variance in annual ionic fluxes can be explained by a linear dependence on snow accumu-lation rate.
A 16.8 m firn core of middle Himalayas was recovered on the col of Dasuopu glacier in August 2006, being 7000 m above sea level. A total of 317 samples were measured for stable oxygen isotope ratios (δ18O) and major ion concentrations (Na +, NH4 + , K +, Mg2 +, Ca2 +, Cl ?, SO42 ?, and NO3?). The firn core dating and seasonal partitioning were carried out on the marked seasonal variations along the stable oxygen isotopes and crustal species (Ca2 +, Mg2 +) profiles. multi-parameters and high-resolution glaciochemical data set of Dasuopu firn core recorded the detailed chemical characteristics of pre-cipitation in high-elevation region, middle Himalayas, since 1991 AD, which mainly originated from the crustal and anthropogenic sources, while the sea- salt contribution was minor. The seasonal variability of major ion concentrations was dominated by the seasonal alternation of the prevalent air mass, at-mospheric circulation and precipitation regime. Linear regression analysis indicated that most of t he variance in annual ionic fluxes can be explained by a linear dependence on snow accumulation rate.