摘要
By using the Arctic runoff data from R-ArcticNET V4.0 and ArcticRIMS,trends of four major rivers flowing into the Arctic Ocean,whose climate factor plays an important role in determining the variability of the Arctic runoff,are investigated.The results show that for the past 30 years,the trend of the Arctic runoff is seasonally dependent.There is a significant trend in spring and winter and a significant decreasing trend in summer,leading to the reduced seasonal cycle.In spring,surface air temperature is the dominant factor influencing the four rivers.In summer,precipitation is the most important factor for Lena and Mackenzie,while snow cover is the most important factor for Yenisei and Ob.For Mackenzie,atmospheric circulation does play an important role for all the seasons,which is not the case for the Eurasian rivers.The authors further discuss the relationships between the Arctic runoff and sea ice.Significant negative correlation is found at the mouth of the rivers into the Arctic Ocean in spring,while significant positive correlation is observed just at the north of the mouths of the rivers into the Arctic in summer.In addition,each river has different relationship with sea ice in the eastern Greenland Sea.
By using the Arctic runoff data from R-ArcticNET V4.0 and ArcticRIMS,trends of four major rivers flowing into the Arctic Ocean,whose climate factor plays an important role in determining the variability of the Arctic runoff,are investigated.The results show that for the past 30 years,the trend of the Arctic runoff is seasonally dependent.There is a significant trend in spring and winter and a significant decreasing trend in summer,leading to the reduced seasonal cycle.In spring,surface air temperature is the dominant factor influencing the four rivers.In summer,precipitation is the most important factor for Lena and Mackenzie,while snow cover is the most important factor for Yenisei and Ob.For Mackenzie,atmospheric circulation does play an important role for all the seasons,which is not the case for the Eurasian rivers.The authors further discuss the relationships between the Arctic runoff and sea ice.Significant negative correlation is found at the mouth of the rivers into the Arctic Ocean in spring,while significant positive correlation is observed just at the north of the mouths of the rivers into the Arctic in summer.In addition,each river has different relationship with sea ice in the eastern Greenland Sea.
基金
The National Natural Science Foundation of China under contract Nos 40676003 and 40876099
the National Basic Research Program of China under contract No. 2006CB403605
"Hundred Talent Program" of the Chinese Academy of Sciences,the China Meteorological Administration under contract No. GYHY200806006
the National Key Technology R&D Program under contract No. 2008AA121704
