北冰洋上层双扩散阶梯热通量的分析

Analysis of the double-diffusive heat flux in the upper Arctic Ocean

北冰洋中,低温低盐的上层水与高温高盐的大西洋水之间,广泛存在着稳定的双扩散阶梯。基于锚定剖面仪、冰基剖面仪和微结构剖面仪的数据,对温盐廓线中的阶梯进行研究,分析阶梯的热通量。固定跟踪了锚定剖面仪的3个阶梯,研究阶梯参数随时间的变化。发现由经验公式得出的上下两界面的热通量差,与混合层内热量的变化有较好的相关性。利用微结构剖面仪数据,计算阶梯界面通过分子热传导输送的热通量。当选取最大位温梯度时,算出的传导热通量与经验公式算出的热通量接近。因此,实验室研究得到的热通量经验公式,可以用于计算北冰洋双扩散阶梯的热通量。

Double-diffusive staircases are located between the cold,fresh upper water and the warm,salty Atlantic Water in the Arctic Ocean.Based on the data of Moored Profiler,Ice-Tethered Profilers,and Microstructure Profi-ler,heat flux across the staircases were analyzed.Three staircases in Moored profiles were traced to study the tem-poral evolution of hydrographical properties of the staircases.Heat flux differences between the upper and lower interfaces were correlated with heat variance of the mixed layer.With the data of Microstructure Profiler,heat flux across the interface was estimated by the assumption of the molecular heat conduction being dominated.When the maximum potential temperature gradient was taken,the result was close to that based on the empirical formula of heat flux.Therefore,it was confirmed that empirical formula of heat flux obtained from the laboratory experiments can be applied in the diffusive convection of the Arcitc Ocean.