北极海冰覆盖范围和海冰密集度的显著减少，导致夏季更多的太阳辐射能够透过海冰加热海水。同时，融冰水使得北冰洋表层出现层化。海水获得的能量得以不断的积累，在盐跃层之下形成了次表层暖水。观测资料显示夏季产生的次表层暖水可以一直维持到次年的春季才消失，因此，次表层暖水对海冰融化和冻结的作用不可忽视。目前对于次表层暖水的维持机制的研究甚少，本项目采用现场观测数据和冰海耦合模式，对冰下海水运动、海洋层化，以及次表层能量的积累过程进行深入研究，探讨北极海洋季节性盐跃层与次表层暖水相互依存的关系，揭示次表层暖水的维持机制，进一步加深冰下海水能量累积对海冰正反馈作用的认识。

Sea ice coverage and sea ice concentration was significantly reduced in Arctic, resulting in more solar radiation in summer through the sea ice heated the seawater. At the same time, stratified seawater occurred by the melting ice in the upper ocean. With the continuous accumulation of the energy the near sea-surface temperature maximum is formed under the halocline. The measured data show that the near sea-surface temperature maximum may disappear until the next spring. Therefore, the near sea-surface temperature maximum can't be ignored on sea ice melting and freezing action. At present the study on the maintenance mechanism of the near sea-surface temperature maximum is little. This project will focus on the field observation data and sea-ice coupled model to study the water movement under the seaice, ocean stratification and the energy accumulation process of the near sea-surface temperature maximum. By these results, the interdependence on the ocean stratification and the near sea-surface temperature maximum is explored, as well as the maintaining mechanism surface warm water is revealed. The ice seawater energy further deepen the understanding of the role of positive feedback accumulated on the sea ice.