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3.10.1 Overview

The model is forced with climatological wind stress data and surface flux data from DaSilva [10]. Climatological data from Levitus [36] is used to initialize the model hydrography. Levitus seasonal climatology data is also used throughout the calculation to provide additional air-sea fluxes. These fluxes are combined with the DaSilva climatological estimates of surface heat flux and fresh water, resulting in a mixed boundary condition of the style described in Haney [25]. Altogether, this yields the following forcing applied in the model surface layer.


$\displaystyle {\cal F}_{u}$ $\displaystyle =$ $\displaystyle \frac{\tau_{x}}{\rho_{0} \Delta z_{s}}$ (3.30)
$\displaystyle {\cal F}_{v}$ $\displaystyle =$ $\displaystyle \frac{\tau_{y}}{\rho_{0} \Delta z_{s}}$ (3.31)
$\displaystyle {\cal F}_{\theta}$ $\displaystyle =$ $\displaystyle - \lambda_{\theta} ( \theta - \theta^{\ast} )
- \frac{1}{C_{p} \rho_{0} \Delta z_{s}}{\cal Q}$ (3.32)
$\displaystyle {\cal F}_{s}$ $\displaystyle =$ $\displaystyle - \lambda_{s} ( S - S^{\ast} )
+ \frac{S_{0}}{\Delta z_{s}}({\cal E} - {\cal P} - {\cal R})$ (3.33)

where $ {\cal F}_{u}$, $ {\cal F}_{v}$, $ {\cal F}_{\theta}$, $ {\cal F}_{s}$ are the forcing terms in the zonal and meridional momentum and in the potential temperature and salinity equations respectively. The term $ \Delta z_{s}$ represents the top ocean layer thickness in meters. It is used in conjunction with a reference density, $ \rho_{0}$ (here set to $ 999.8\,{\rm kg\,m^{-3}}$), a reference salinity, $ S_{0}$ (here set to 35 ppt), and a specific heat capacity, $ C_{p}$ (here set to $ 4000~{\rm J}~^{\circ}{\rm C}^{-1}~{\rm kg}^{-1}$), to convert input dataset values into time tendencies of potential temperature (with units of $ ^{\circ}{\rm C}~{\rm s}^{-1}$), salinity (with units $ {\rm ppt}~s^{-1}$) and velocity (with units $ {\rm m}~{\rm s}^{-2}$). The externally supplied forcing fields used in this experiment are $ \tau_{x}$, $ \tau_{y}$, $ \theta^{\ast}$, $ S^{\ast}$, $ \cal{Q}$ and $ \cal{E}-\cal{P}-\cal{R}$. The wind stress fields ($ \tau_x$, $ \tau_y$) have units of $ {\rm N}~{\rm m}^{-2}$. The temperature forcing fields ( $ \theta^{\ast}$ and $ Q$) have units of $ ^{\circ}{\rm C}$ and $ {\rm W}~{\rm m}^{-2}$ respectively. The salinity forcing fields ($ S^{\ast}$ and $ \cal{E}-\cal{P}-\cal{R}$) have units of $ {\rm ppt}$ and $ {\rm m}~{\rm s}^{-1}$ respectively. The source files and procedures for ingesting this data into the simulation are described in the experiment configuration discussion in section 3.10.3.


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Next: 3.10.2 Discrete Numerical Configuration Up: 3.10 Global Ocean MITgcm Previous: 3.10 Global Ocean MITgcm   Contents
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