楚科奇海-白令海-北太平洋表层海水中放射性铯分布特征及关联OA北大核心CSCDCSTPCD

In this study,the distribution characteristics and transport paths of cesium-137(137Cs)in the Chukchi Sea,Bering Sea,and North Pacific Ocean were analyzed by combining the activity data from surface water collected during China's 10th Arctic scientific expedition with regional hydrological characteristics.Our findings indicate that 137Cs exhibited a low activity concentration in the Chukchi Sea(0.20-0.49 Bq·m-³),indicating that it was only minimally affected by water inflow from the Bering Sea.In the Bering Sea,the activity concentration of 137Cs was unevenly distributed(0.41-1.08 Bq·m-3).Additionally,a high-value area was observed in the southern part of the western basin,which was attributed to the migration of low-temperature,high-salinity subsurface water resulting from the winter subsidence of the Aleutian North Slope current.It was also observed that a high-value area in the eastern continental shelf was affected by the inflow of the continental shelf current.In the North Pacific Ocean,the 137Cs activity concentration exhibited a patchy distribution(0.27-1.21 Bq·m-³),with a distinct low-value area that confirmed the barrier effect of the Subarctic Current on pollutants.The absence of a significant difference in the distribution of 137Cs activity concentration in the Bering Sea and North Pacific Ocean indicated that the 137Cs-traced radioactive materials were transported and dispersed by ocean currents,leading to a homogenization trend across a wide range of oceans and marginal seas.Overall,this study provides a scientific basis for assessing the migration of nuclear pollutants toward the Arctic.