Water mass of the northward throughflow in the Bering Strait in the summer of 2003

The temperature and salinity data obtained by the Chinese national arctic research expedition (CHINARE2003) are used to study the water structure in the Bering Strait and ambient regions.Four water masses appeared in the research region:the intermediate Bering Sea water mass (IBWM), the Alaska coastal water (ACW), the Anadyr water (AW) and the Bering shelf water (BSW).The AW originates from the IBWM, but the upper layer water has been greatly altered.In the cruise on 28/29 July 2003, there were only the BSW and ACW in a section across the Bering Strait (BS section), but in the September 12/13 cruise, the AW, BSW and ACW flowed parallelly into the Bering Strait.The upper waters of these water masses were all altered due to ice melting, runoff, solar radiation, and wind mixing.The waters in the central and northern parts of Bering Strait stratified by two uniform layers, were expressed as the typical feature of the water masses originating from the pacific.A two-layer structure also dominated the vertical stratification in most part of the Chukchi Sea.An obvious subseasonal variation was observed in the BS section, which caused varying transportation of fresh water, heat, and substance, and produced a long-term and extensive impact on the Arctic Ocean.