Acceleration of Glacier Wastage in the Arctic System: Facts, Causes and What to Expect

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Glaciers are ubiquitous features of the Arctic archipelagos, islands, and borderlands around the Greenland Ice Sheet. A significant fraction of the freshwater that feeds the northern seas is derived from glaciers in the pan-Arctic and for the most part, this meltwater discharges directly to the ocean rather than into the major Arctic rivers. Thus, water balance on land, calculated using the gauged discharges, is a poor estimate of the real water balance. Arctic glaciers have had negative mass balances in recent decades due to climate warming. This increasing contribution of runoff, which is spatially and temporally different from normal precipitation-derived river runoff, affects inflow to the Arctic Ocean and other northern waters. This change in turn affects the future environment in the pan-Arctic region as well as global sea level, imposing feedbacks to climate, the environment, the economy, and to change in the geosphere. This three-year project includes new regional syntheses of glacier volume change and runoff using new data sources and methodologies, leading to better understanding of the processes that are causing increased glacier wastage. This synthesis will bring a better understanding of the role of glaciers to the scientific community and provide background for projecting future changes. Intellectual merit of the proposed research includes: It will present the relationship between several scientific disciplines, involving glaciology, climatology, oceanography, environmental change, and other geosciences. Glacier seasonal balances will provide useful information on climate processes, especially precipitation, and as the basis for hydrologic studies in parts of the Arctic region. By estimating the melt-water exchange between land and ocean due to receding glaciers, it will help us to understand the changes in Earth's gravitational and rotational field, as well as ocean circulation and the pattern of sea-level change. New analysis techniques, such as the template method for expanding results spatially, and new ways to calculate size distributions, will contribute new tools for researchers to use in other fields. Broad implication of the proposed research: This will be the first quantitative analysis, with carefully estimated accuracy, of glacier change in the pan-Arctic for the period of instrumental observations. As such, it will have broad impact on the interdisciplinary scientific community. The time-series results will serve as a necessary source of data for validation of model results and projection of future change. These environmental changes will have noticeable effects on Arctic processes, such as ocean thermohaline circulation, biota, local economy and life of indigenous people in USA, Canada, Russia, and other Arctic countries.