An Argo-Derived Background Diffusivity Parameterization for Improved Ocean Simulations in the Tropical Pacific
An Argo-Derived Background Diffusivity Parameterization for Improved Ocean Simulations in the Tropical Pacific
复制标题
用于改进热带太平洋海洋模拟的 Argo 背景扩散率参数化
DOI：
10.1002/2017gl076269
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发表时间：
2018
影响因子：
5.2
通讯作者：
Zhang Rong-Hua
中科院分区：
文献类型：
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作者：
Zhu Yuchao;Zhang Rong-Hua
在热带太平洋的海洋和海-气耦合模拟中，模式偏差是很严重的，包括太冷的舌头和太分散的温跃层。这些偏差可以部分归因于垂直混合参数，其中背景扩散率的描述具有很大的不确定性。在细尺度参数化的基础上，利用ARGO资料计算了热带太平洋大部分地区的空间变化的背景扩散系数Ofo(10−6m2s−1)。这一新方案随后被用于基于模块化海洋模式的海洋模式和耦合模式5.1版，大大改进了海洋模拟，包括更逼真的冷舌和赤道温跃层。改进的模拟可以归因于减弱的赤道上升流所引起的降温效应的减弱。此外，次表层冷却效应是由于上层到次表层的换热减少和赤道外较冷的水汇聚所致。
Model biases are substantial in ocean and coupled ocean‐atmosphere simulations in the tropical Pacific Ocean, including a too cold tongue and too diffuse thermocline. These biases can be partly attributed to vertical mixing parameterizations in which the background diffusivity depiction has great uncertainties. Here based on the fine‐scale parameterization, the Argo data are used to derive the spatially varying background diffusivity, with a magnitude ofO(10−6m2s−1) in the most area of tropical Pacific. This new scheme is then employed into the version 5.1 of the Modular Ocean Model‐based ocean‐only and coupled models, resulting in substantial improvements in ocean simulations, including a more realistic cold tongue and equatorial thermocline. The improved simulations can be attributed to the reduced cooling effects induced by weakened equatorial upwelling. Additionally, the subsurface cooling effect is attributed to the reduced heat transfer from the upper layer to the subsurface layer and the convergence of the colder water from off the equator.