摘要
Almost half of the oceanic water columns exhibit double-diffusion. The importance of double-diffusion in global oceans’ salt and heat fluxes, water-mass formation and mixing, and circulation is increasingly recognized. However, such an important physical process in the ocean has not been well studied. One of the reasons is the difficulty of parameterizing and quantifying the processes. The paper presented here attempts to quantify the double-diffusive fluxes of salt and heat in the ocean. Previous qualitative analysis by applying the water-mass Turner angle, mTu, to the North Pacific Intermediate Water (NPIW) layer showed a favorable condition for salt-fingering in the upper NPIW due to the overlying warm/salty water above the cold/fresh NPIW core, and a doubly-stable condition in the lower NPIW where potential temperature decreases with depth while salinity increases, inducing double stratification with respect to both potential temperature and salinity. The present study gives a quantitative estimate of double-diffusive fluxes of salt and heat contributed by salt-fingering in the upper NPIW layer.
Almost half of the oceanic water columns exhibit double-diffusion. Theimportance of double-diffusion in global oceans' salt and heat fluxes, water-mass formation andmixing, and circulation is increasingly recognized. However, such an important physical process inthe ocean has not been well studied. One of the reasons is the difficulty of parameterizing andquantifying the processes. The paper presented here attempts to quantify the double-diffusive fluxesof salt and heat in the ocean. Previous qualitative analysis by applying the water-mass Turnerangle, mTu, to the North Pacific Intermediate Water (NPIW) layer showed a favorable condition forsalt-fingering in the upper NPIW due to the overlying warm/salty water above the cold/fresh NPIWcore, and a doubly-stable condition in the lower NPIW where potential temperature decreases withdepth while salinity increases, inducing double stratification with respect to both potentialtemperature and salinity. The present study gives a quantitative estimate of double-diffusive fluxesof salt and heat contributed by salt-fingering in the upper NPIW layer.
基金
a result of my short visit to the Physical Oceanography Laboratory of Ocean University of ChinaQingdao with support from the Foundation for Open Projects of the Key Lab.of Physical Oceanography,the Ministry of Education,China(No.200401).
关键词
北太平洋
介质水流
双扩散
盐分
热量
NPIW
double-diffusion
salt-fingering
double-diffusive fluxes of heat and salt
water-mass turner angle
NPIW
north pacific