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The large magnitude of predicted warming at high latitudes and the potential feedback of ecosystems to atmospheric CO concentrations make it important to quantify both warming and its effects on high-latitude carbon balance. We analysed long-term, daily surface meteorological records for 13 sites in Alaska and north-western Canada and an 82-y record of river ice breakup date for the Tanana River in interior Alaska. We found increases in winter and spring temperature extrema for all sites, with the greatest increases in spring minimum temperature, average 0.47 degree C per 10 y, and a 0.7-day per 10 y advance in ice breakup on the Tanana River. We used the climate records to drive an ecosystem process model, BIOME_BGC,...
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In terrestrial high-latitude regions, observations indicate recent changes in snow cover, permafrost, and soil freeze?thaw transitions due to climate change. These modifications may result in temporal shifts in the growing season and the associated rates of terrestrial productivity. Changes in productivity will influence the ability of these ecosystems to sequester atmospheric CO2. We use the terrestrial ecosystem model (TEM), which simulates the soil thermal regime, in addition to terrestrial carbon (C), nitrogen and water dynamics, to explore these issues over the years 1960?2100 in extratropical regions (30?90°N). Our model simulations show decreases in snow cover and permafrost stability from 1960 to 2100. Decreases...
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In terrestrial high-latitude regions, observations indicate recent changes in snow cover, permafrost, and soil freeze?thaw transitions due to climate change. These modifications may result in temporal shifts in the growing season and the associated rates of terrestrial productivity. Changes in productivity will influence the ability of these ecosystems to sequester atmospheric CO2. We use the terrestrial ecosystem model (TEM), which simulates the soil thermal regime, in addition to terrestrial carbon (C), nitrogen and water dynamics, to explore these issues over the years 1960?2100 in extratropical regions (30?90°N). Our model simulations show decreases in snow cover and permafrost stability from 1960 to 2100. Decreases...
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