Response of the atmospheric hydrologic cycle over the Arctic to climate change in CCSM3

Through influences on the freshwater content of the Arctic Ocean, the atmospheric hydrologic cycle over the Arctic has the ability to affect climate on a grand scale. The representation of this cycle within version 3.0 of the Community Climate System Model (CCSM3) has been found to be reasonable over the North Atlantic and the majority of Eurasia, although the model's hydrology is flawed within the Mackenzie River Basin. Keeping these strengths and weaknesses in mind, this study relates variability in the Arctic Hydrology to atmospheric circulation in both control and climate change runs of CCSM3. Composite analysis has been used to identify atmospheric circulation patterns associated with basin-scale hydrologic variability. The similarity of these patterns to those found in observations is discussed, as is their adjustment to climate change. Finally, the climate change response of the atmospheric hydrologic cycle is related to other elements of the Arctic freshwater budget.