ИСТИНА

In Alpine climate zone the storage of precipitation in snowpack, and the subsequent spring melting, substantially impacts the water cycle. Julian Alps and Karavanke represent southern part of Eastern Alps and are under the influence of mixing air masses that influence considerably accumulation of snow and its characteristics. Stable isotopes of oxygen have been used to study snow deposition and the subsequent alteration of snowpack characteristics worldwide. However, in Slovenia we started with snow isotope investigations only recently. We performed first isotope investigations of snow in 2011 and collected samples from 5 snow profiles in Julian Alps. We continued in winter 2011/12 when sampling of snow profiles was limited due to particular climate conditions (i. e. low precipitation) and 7 snow pits were investigated in Julian Alps and Karavanke. In winter 2012/13 we expanded sampling to more locations and investigated 21 snow pits in Julian Alps and 2 in Karavanke. We tested few different sampling techniques and determined in all collected samples isotopic composition of oxygen. Heterogeneities in snow profiles formed during warmer periods typical for winters in alpine part of Slovenia caused some problems in representative snow sampling and also in interpretation of results obtained. We observed considerable variations in isotopic composition of snow in time and space, and also in particular snow profile. Changes in isotopic composition through the profiles indicate the influence of dry and wet metamorphism, phase changes due to the influence of snow sublimation and vapour diffusion through the snowpack, different precipitation events and changing conditions during few days snow precipitation event.