摘要
上层海洋混合过程的动力学研究和数值模拟一直是海洋和气象学家关注的重点之一,其中上层海洋垂向混合参数化方案的不准确直接影响海洋模式的模拟效果。风生海浪对海气相互作用以及上层海洋的内部混合都起到极为重要的作用。本文基于包含垂向层结效应的海浪生湍流混合系数理论模型,开展不同层结条件下海浪生湍流混合系数的分布变化特征分析。构建了一维理想解析实验和准全球算例,结果表明,在100 m以浅的上层海洋中,混合层深度与上述混合系数呈现较为显著的负相关关系,当跃层或混合层深度较大时能够显著增强垂向混合过程,进而使表层暖水下降至更深的位置,加深混合层深度模拟结果。主要原因是由于深跃层条件下表层的层结效应较弱,因而对混合的抑制作用较小。此外,在准全球算例中海浪生湍流混合方案可显著提高海洋环流模式对上层海洋温度结构的模拟能力,模式对跃层处WOA13实测数据的模拟精度最高可提升60%以上。
Dynamics and numerical simulation of the mixing processes in the upper ocean have always been one of the key concerns of the oceanographers and meteorologists,the accuracy of the vertical mixing parameterization scheme can directly affect the skill of ocean models.The wind-driven waves play an extremely important role in the air-sea interaction and the internal mixing in upper ocean.In this paper,based on theoretical model of mixing coefficients of the wave-generated turbulence containing vertical stratification variation effect,analysis of the distribution and variation characteristics of the mixing coefficients under different stratification conditions is performed.One-dimensional ideal and quasi-global experiments are designed,and the results show that the mixed layer depths are negatively correlated with the mixing coefficients in upper ocean shallower than 100 m.The vertical mixing processes are strengthened when thermocline or mixed layer depth is deep,thus warmer water in surface later tends to be easily convected to deeper ocean,causing the simulated mixed layer depth deeper.This is because the stratification is relatively weak when thermocline is deeper,so the suppression to mixing processes become weaker.In addition,wave-generated turbulent mixing schemes are able to dramatically improve the simulation accuracy of the upper ocean temperature structure in the quasi-global experiments,and the accuracy of simulating the WOA13 multi-year monthly mean data in the thermocline regions can increased up to more than 60%.
作者
庄展鹏
袁业立
ZHUANG Zhanpeng;YUAN Yeli(First Institute of Oceanography,MNR,Qingdao 266061,China;Key Laboratory of Marine Science and Numerical Modeling,MNR,Qingdao 266061,China;Laboratory for Regional Oceanography and Numerical Modeling,Laoshan Laboratory,Qingdao 266061,China)
出处
《海洋科学进展》
CAS
CSCD
北大核心
2024年第3期437-451,共15页
Advances in Marine Science
基金
国家重点研发计划项目(2022YFC3104803、2022YFA1004403和2022YFC2808304)
中央级公益性科研院所基本科研业务费专项资金资助项目(2020Q04)
国家自然科学基金项目(42106031和62231028)
崂山实验室专项经费资助项目(LSKJ202202101)
全球变化与海气相互作用二期项目(GASI-04-WLHY-01和GASI-04-WLHY-02)。
关键词
海浪生湍流混合
垂向层结条件
海洋环流数值模拟
跃层深度
wave-generated turbulent mixing
vertical stratification condition
numerical modeling of ocean circulation
thermocline depth