A Parameterization Scheme for Wind Wave Modules that Includes the Sea Ice Thickness in the Marginal Ice Zone

Abstract

The global wave model WAVEWATCH III®; works well in open water. To simulate the propagation and attenuation of waves through ice-covered water, existing simulations have considered the influence of sea ice by adding the sea ice concentration in the wind wave module; however, they simply suppose that the wind cannot penetrate the ice layer and ignore the possibility of wind forcing waves below the ice cover. To improve the simulation performance of wind wave modules in the marginal ice zone (MIZ), this study proposes a parameterization scheme by directly including the sea ice thickness. Instead of scaling the wind input with the fraction of open water, this new scheme allows partial wind input in ice-covered areas based on the ice thickness. Compared with observations in the Barents Sea in 2016, the new scheme appears to improve the modeled waves in the high-frequency band. Sensitivity experiments with and without wind wave modules show that wind waves can play an important role in areas with low sea ice concentration in the MIZ.

摘 要

全球海浪模式WAVEWATCH III®在开阔水域有良好的模拟结果。为了模拟海浪在海冰覆盖海域的传播和衰减,现有的模式通过在风浪模块中添加海冰密集度来考虑海冰的影响;然而,现有模式只是假设风不能穿透冰层,而忽略了风在冰盖下推动海浪的可能性。为了提高海冰边缘区(MIZ)风浪模块的模拟能力,本文提出了一种包括海冰厚度的风浪模块参数化方案。新方案代替了根据海冰密集度缩放风应力输入的原始方案,允许风应力基于海冰厚度在海冰覆盖区域输入海面。与2016年巴伦支海的观测结果相比,新方案改善海浪的高频部分。此外,根据风浪模块的敏感性实验,在MIZ海冰密集度低的区域,风浪仍发挥重要作用。