摘要
In this study, we mainly introduce two salinity parameterization schemes used in Sea Ice Simulator （SIS）, that is, isosaline scheme and salinity profile scheme. Comparing the equation of isosaline scheme with that of salinity profile scheme, we found that there was one different term between the two schemes named the salinity different term. The thermodynamic effect of the salinity difference term on sea ice thickness and sea ice concentration showed that： in the freezing processes from November to next May, the sea ice temperature could rise on the influence of the salinity difference term and restrain sea ice freezing; at the first melting phase from June to August, the upper ice melting rate was faster than the lower ice melting rate. Then sea ice temperature could rise and accelerate the sea ice melting; at the second melting phase from September to October, the upper ice melting rate was slower than the lower ice melting rate, then sea ice temperature could decrease and restrain sea ice melting. However, the effect of the salinity difference term on the sea ice thickness and sea ice concentration was weak. To analyze the impacts of the salinity different term on Arctic sea ice thickness and sea ice concentration, we also designed several experiments by introducing the two salinity parameterizations to the ice-ocean coupled model, Modular Ocean Model （MOM4）, respectively. The simulated results confirmed the previous results of formula derivation.
本文详细介绍了SIS海冰模式中引进两种盐度参数化方案即等盐度方案和盐度廓线方案对海冰模拟所存在的差异。利用盐度廓线方案导出的表征盐度与海冰温度间关系的方程比等盐度方案多出一项,将定义为盐度差异项。盐度差异项对海冰厚度的热力作用表现为:在海冰厚度增长季节(11月到次年5月),盐度差异项通过升高海冰内部温度,抑制海冰增长;在消融的第一阶段(6-8月),盐度差异项通过升高海冰内部温度加快海冰消融;在消融的第二阶段(9-10月),盐度差异项通过降低海冰内部的温度抑制海冰消融。但尺度分析表明,盐度差异项要比方程中队海冰温度作用最大项小1-2个量级,如果采用一级近似,可以略去盐度差异项,因此盐度差异项对海冰增长和消融影响很小。同时利用冰洋耦合模式(Modular Ocean Model,MOM4),分别采用两种盐度参数化方案模拟北极海冰厚度和海冰密集度的季节性变化,模拟结果也表明两种方案模拟得到的海冰厚度和海冰密集度的季节性变化相差甚小。
基金
supported by the National Natural Science Foundation of China(No.41075030,41106004,41106159 and 41206013)
the Ocean Public Welfare Science Research Project,State Oceanic Administration,People's Republic of China(No.201005019)
