Impact of snow deposition on major and trace element concentrations and fluxes in surface waters of Western Siberian Lowland
Vladimir P. Shevchenko1, Oleg S. Pokrovsky2, Sergey N. Vorobyev3, Ivan V. Krickov3, Rinat M. Manasypov3,4, Nadezhda V. Politova1, Sergey G. Kopysov3, Olga M. Dara1, Yves Auda2, Liudmila S. Shirokova2,4, Larisa G. Kolesnichenko3, Valery A. Zemtsov3, and Sergey N. Kirpotin31Shirshov Institute of Oceanology RAS, 36 Nakhimovsky Pr., Moscow, Russia 2Geosciences Environment Toulouse, UMR 5563 CNRS, University of Toulouse, 14 Avenue Edouard Belin 31400, Toulouse, France 3BIO-GEO-CLIM Laboratory, Tomsk State University, 36 Lenina, Tomsk, Russia 4Institute of Ecological Problems of the North, 23 Nab Severnoi Dviny, RAS, Arkhangelsk, Russia
Received: 07 Nov 2016 – Accepted for review: 22 Nov 2016 – Discussion started: 22 Nov 2016
Abstract. Towards a better understanding of chemical composition of snow and its impact on surface water hydrochemistry in poorly studied Western Siberia Lowland (WSL), dissolved (melted snow) and particulate (> 0.45 μm) fractions of snow were sampled in February 2014 across a 1700-km latitudinal gradient (c.a. 56.5 to 68° N) in essentially pristine regions. Concentration of dissolved Fe, Co, Cu, As, La, increased by a factor of 2 to 5 north of 63° N. The pH, Ca, Mg, Sr, Mo and U dissolved concentration in snow water increased with the increase in concentration of particulate fraction (PF), which was also correlated with the increase in calcite and dolomite proportion in the mineral fraction, suggesting an enrichment of meltwater by these elements during dissolution of carbonate minerals. The concentrations of Al, Fe, Pb, La and other insoluble elements in < 0.45 μm-filtered snow water decreased with the increase in PF. Principal Component Analyses revealed F1xF2 structure of major and trace element concentration in both dissolved and particulate fractions, with 2 factors not linked to the latitude. Sr, Mo, Sb, U, and, partially, Cu and Zn were most sensitive to the latitude of the sampling. The main sources of mineral components in PF are desert and semi-desert regions of central Asia.
Comparison of major and trace elements in dissolved fraction of snow with lakes and rivers of western Siberia across the full latitude profile revealed significant atmospheric input of a number of trace elements. The snow water concentration of DIC, Cl, SO4, Mg, Ca, Cr, Co, Ni, Cu, Mo, Cd, Sb, Cs, W, Pb and U exceeded or were comparable with spring-time concentration in thermokarst lakes of the region. The spring-time river fluxes (May–June, representing the snow melt period) of DIC, Cl, SO4, Na, Mg, Ca, Rb, Cs, metals (Cr, Co, Ni, Cu, Zn, Cd, Pb), metalloids (As, Sb), Mo and U in the discontinuous to continuous permafrost zone (64–68° N) can be fully explained by melting of accumulated snow. Therefore, the present study demonstrates significant and previously underestimated atmospheric input of many major and trace elements to their riverine fluxes during spring flood. The impact of snow deposition strongly increased northward, in discontinuous and continuous permafrost zones of frozen peat bogs, which is consistent with the decrease of the impact of rock lithology on river chemical composition in the permafrost zone of WSL, relative to the permafrost-free regions.
Shevchenko, V. P., Pokrovsky, O. S., Vorobyev, S. N., Krickov, I. V., Manasypov, R. M., Politova, N. V., Kopysov, S. G., Dara, O. M., Auda, Y., Shirokova, L. S., Kolesnichenko, L. G., Zemtsov, V. A., and Kirpotin, S. N.: Impact of snow deposition on major and trace element concentrations and fluxes in surface waters of Western Siberian Lowland, Hydrol. Earth Syst. Sci. Discuss., doi:10.5194/hess-2016-578, in review, 2016.
Full data set of major and TE concentration in snow water
V. P. Shevchenko, O. S. Pokrovsky, S. N. Vorobyev, I. V. Krickov, R. M. Manasypov, N. V. Politova, S. G. Kopysov, O. M. Dara, Y. Auda, L. S. Shirokova, L. G. Kolesnichenko, V. A. Zemtsov, and S. N. Kirpotin