Run-off water of Amur River and sea ice extents in Okhotsk Sea

摘要

The sea ice covered the Okhotsk Sea during winter season in the most southern latitude of the northern hemisphere. It is known that sea ice formation is caused by the inflow of much fresh water from Amur River. To clarify whether the sea ice extents is associated with the discharge of the Amur River, it is analyzed the interannual variations between the Amur River discharge and the extents of the sea ice in the Okhotsk Sea. It is shown that the sea ice extents is decreasing when the Amur River discharge is increasing, whereas the sea ice coverage is larger area than usual when the Amur River discharge is decreasing. It is also performed the lag correlation analysis between the interannual variations of the discharge of the Amur River and sea ice extents. The Amur River discharge is increasing for five years later than the maximum extents of sea ice is occurred. On the contrary, the maximum extents of sea ice is occurred for five years later than the higher amount of discharge of the Amur River. Therefore, we could conclude that the Amur River is really important for the formation of the sea ice in the Okhotsk Sea.