Dominant Climate Factors Influencing The Arctic Runoff And Association Between The Runoff And Arctic Sea Ice

The Arctic can be viewed as an integrated system, characterized by intimate couplings between it atmosphere, ocean and sea ice, linked in turn to the larger global system. River inflow is the major part of the Arctic freshwater budget, and of special importance in the Arctic Ocean. This paper discusses the seasonal and decadal variation, dominant climate factors of the arctic runoff, and association between the arctic runoff and sea ice; then using a coupled ice-ocean model studies the impacts on the ocean and sea ice; finally sets up arctic regional model to simulate the climate mean sate of the Arctic Ocean and sea ice.The results suggest that the arctic runoff exhibits an increasing trend for spring and winter and a decreasing trend in summer. The surface air temperature is the dominant factor in influencing for all the four rivers in spring. In summer, snow cover is the most important factor for the Ob and Yenisei rivers, while precipitation is the most important factor for Lena and Mackenzie. For Mackenzie, atmospheric circulation does play an important role for all the seasons, which is not the case for the Eurasian rivers. We further discuss the relationships between the Arctic runoff and sea ice. It shows significant relation in estuaries and sea ice edge, such as east Greenland current, Siberian coast and so on. It is noteworthy that Lena impacts the sea ice along east Greenland remarkably, negatively correlated in spring and winter, positively correlated in summer and autumn.The model results are similar to the observation results. The influence to sea ice is in its edge, such as east Greenland current and the sea area between Svalbard and Novaya Zemlya, an oceanic front. The sea ice concentration and thickness increase along east Greenland, decrease between Svalbard and Novaya Zemlya as the runoff rises in spring and winter. The summer and autumn situation are similar to the spring when the summer runoff reduces. The main affected zone to salinity is estuarine area. Relations between salinity and runoff are obvious anti-phase changed. When runoff increase in spring and winter, decrease in summer and autumn, the downwelling in the north Atlantic becomes weaken.The regional model and global model have merits and demerits. Regional model sea ice results are better in winter, while global model results are better in summer. For the salinity and temperature simulations, regional model is better in Atlantic layer and global model in surface.