Chemical fingerprints in Svalbard snow and ice to understand the changes occurring in Arctic

The annual snow layer, during the winter, covers most of the Svalbard archipelago, becoming one of the most important factors influencing the Svalbard environment. The annual snow layer is an extremely dynamic portion of the Cryosphere and can be defined as the snow accumulated and present on the ground during the year. The characteristics of the annual snow strata are strongly dependent on climate conditions and can influence the access to food, particularly for animals who rely on food sources below the snow strata. From a chemical point of view, snow depositions during the winter are a sink for an impressive number of chemical compounds (natural and anthropogenic) and elements trapped in the snow layers. Particularly, compounds and elements that can be photo-activated accumulate during the winter and can be re-emitted in the atmosphere, taking part in numerous geochemical and biological cycles during the spring. However, elements that can be photo-activated are not the only ones to be released from the annual snow strata. During the melting phase, all elements and compounds that are still present in the snow can be released in the melting water, accumulate in the ground or be discharged in the sea, affecting biological productivity or, in the case of anthropogenic compounds, causing a spotted contamination of the surrounding environment. The snow research conducted in the Svalbard is fundamental to better understand the whole natural dynamics that characterize the archipelago. Evaluate the photo-activation and re-emission processes can improve our comprehension of seasonal (and daily) atmospheric oscillation not fully understood for specific elements; Improve our knowledge about the chemical composition of annual snow layer can bring important information in which atmospheric, transport and climate processes are affecting the annual snow composition; Evaluate the effect of the specific meteorological events in the chemical and physical structure of the annual snow layer contributed (such as rain occurrences and snow melting events due to rapid temperature oscillations) to understanding the evolution of the snow proprieties; Collect ice core archives from the glacier summit help us in evaluate the recent changing occurring in the higher Arctic. The studies conducted until now and the activities plan for the close future, such as the ongoing 2018/2019 winter campaign, contributed to understanding the evolution of the snow's chemical proprieties as a consequence of the climate changes affecting the archipelago and better define the role of specific meteorological events. Snow research is relevant for the future evaluations of the interaction between snow, atmosphere and better define post-depositional processes able to re-emit andintroduce in the arctic food chain specific elements and compounds, including anthropogenic contaminants and a Snow Super Site close to Ny-Alesund is essential to achieve this goal. Svalbard snow is an unique environment to be studied giving extremely important information regarding a) the biogeochemical cycle of elements and compounds (natural and anthropogenic) b) understand the impact of the local and abroad human activities c) reconstruct the past atmospheric and climate conditions. The snow research, from a chemical and physical point of view, is crucial and complementary to the other research activities to understand the changes occurring in the Arctic Region.