资源环境科技发展态势分析平台

Observational evidences have shown that the increased water vapour and accompanying enhancement of downward infrared radiation (IR) can explain the abrupt warming of surface air temperature (SAT) over the Barents-Kara Seas during boreal winter. This study investigates anomalous moisture transport associated with the abrupt change of SAT since the mid-2000s over the Barents-Kara Seas, since moisture transport contributes to the anomalous water vapour and downward IR. Results show that anomalous stationary moisture flux induces anomalous moisture convergence over the Barents-Kara Seas region, whereas the anomalous transient flux opposes the anomalous moisture convergence there. Hence, the anomalous stationary moisture transport is suggested to be responsible to the increased water vapour over the Barents-Kara Seas region. Further decomposition of the stationary moisture flux indicates that the anomalous moisture convergence associated with the change in atmospheric mean flow plays an important role in the increased water vapour on both interannual and decadal time scales. In addition, decrease in the synoptic-scale eddy activity observed over northern Siberia may contribute to generation of the anomalous atmospheric mean flow via eddy feedback processes.