Formulation of a new ocean salinity boundary condition and impact on the simulated climate of an oceanic general circulation model  

作　　者：JIN JiangBo ZENG QingCun WU Lin LIU HaiLong ZHANG MingHua 

机构地区：[1]Institute of Atmospheric Physics,Chinese Academy of Sciences [2]College of Earth Sciences,University of Chinese Academy of Sciences [3]School of Marine and Atmospheric Sciences,Stony Brook University

出　　处：《Science China Earth Sciences》2017年第3期491-500,共10页中国科学（地球科学英文版）

基　　金：supported by the National Major Research High Performance Computing Program of China(Grant No.2016 YFB0200800);the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No. XDA11010403);the National Natural Science Foundation of China(Grant No.41305028);and the Key Research Program of Frontier Sciences,Chinese Academy of Sciences(Grant No.QYZDY-SSW-DQC002)

摘　　要：The salinity boundary condition at the ocean surface plays an important role in the stability of long-term integrations of an oceanic general circulation model （OGCM） and in determining its equilibrium solutions. This study presents a new formulation of the salt flux calculation at the ocean surface based on physical processes of salt exchange at the air-sea interface. The formulation improves the commonly used virtual salt flux with constant reference salinity by allowing for spatial correlations between surface freshwater flux and sea-surface salinity while preserving the conservation of global salinity. The new boundary condition is implemented in the latest version of the National Key Laboratory of NumericaI Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics/Institute of Atmospheric Physics Climate Ocean Model version 2 （LICOM2.0）. The impact of the new boundary condition on the equilibrium simulations of the model is presented. It is shown that the new formulation leads to a stronger Atlantic meridional overturning circulation （AMOC） that is closer to observational estimates. It also slightly improves poleward heat transport by the oceans in both the Atlantic and the global oceans.The salinity boundary condition at the ocean surface plays an important role in the stability of long-term integrations of an oceanic general circulation model(OGCM) and in determining its equilibrium solutions.This study presents a new formulation of the salt flux calculation at the ocean surface based on physical processes of salt exchange at the air-sea interface.The formulation improves the commonly used virtual salt flux with constant reference salinity by allowing for spatial correlations between surface freshwater flux and sea-surface salinity while preserving the conservation of global salinity.The new boundary condition is implemented in the latest version of the National Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics/Institute of Atmospheric Physics Climate Ocean Model version 2(LICOM2.0).The impact of the new boundary condition on the equilibrium simulations of the model is presented.It is shown that the new formulation leads to a stronger Atlantic meridional overturning circulation(AMOC) that is closer to observational estimates.It also slightly improves poleward heat transport by the oceans in both the Atlantic and the global oceans.

关 键 词：OGCM Surface salinity boundary condition Virtual salinity flux Upward salt flux from oceanic surface AMOC 

分 类 号：P732[天文地球—海洋科学] P731