New URL for NEMO forge!   http://forge.nemo-ocean.eu

Since March 2022 along with NEMO 4.2 release, the code development moved to a self-hosted GitLab.
This present forge is now archived and remained online for history.
Changeset 11677 for NEMO – NEMO

Changeset 11677 for NEMO


Ignore:
Timestamp:
2019-10-11T00:15:29+02:00 (5 years ago)
Author:
agn
Message:

added structure figure

File:
1 edited

Legend:

Unmodified
Added
Removed
  • NEMO/trunk/doc/latex/NEMO/subfiles/chap_ZDF.tex

    r11676 r11677  
    582582ML are handled by the Ri # dependent scheme. 
    583583 
    584 \subsubsection{The structure of the OSBL} 
    585 Figure \ref{OSM1} 
    586  
     584\subsubsection{Depth and velocity scales} 
     585The model supposes a boundary layer of thickness $h_{\mathrm{bl}}$ enclosing a well-mixed layer of thickness $h_{\mathrm{ml}}$ and a relatively thin pycnocline at the base of thickness $\Delta h$; Fig.~\ref{fig: OSBL_structure} shows typical (a) buoyancy structure and (b) turbulent buoyancy flux profile for the unstable boundary layer (losing buoyancy at the surface; e.g.\ cooling). 
     586\begin{figure}[!t] 
     587  \begin{center} 
     588    \includegraphics[width=\textwidth]{Fig_ZDF_OSM_structure_of_OSBL} 
     589    \caption{ 
     590      \protect\label{fig: OSBL_structure} 
     591     The structure of the entraining  boundary layer. (a) Mean buoyancy profile. (b) Profile of the buoyancy flux. 
     592    } 
     593  \end{center} 
     594\end{figure} 
     595The pycnocline is shallow but important, since here the turbulent OSBL interacts with the underlying ocean. In a finite difference model the pycnocline must be at least one model level thick. The pycnocline in the OSMOSIS scheme is assumed to have a finite thickness, and may include a number of model levels. This means that the OSMOSIS scheme must parametrize both the thickness of the pycnocline, and the turbulent fluxes within the pycnocline. 
     596 
     597Consideration of the power input by wind acting on the Stokes drift suggests the Langmuir velocity scale: 
     598\begin{equation}\label{eq:w_La} 
     599w_{*L}= \left(u_*^2 u_{s0}\right)^{1/3}; 
     600\end{equation}  
     601this is the  
     602Where the mixed-layer is stable, a composite velocity scale is assumed: 
     603\begin{equation}\label{eq:composite-nu} 
     604\nu_{\ast}= \left{}u_*^3 \left[\right]1-exp(-1.5 \mathrm{La}_t^2})\right]+w_{*L}^3\right}^{1/3} 
     605\end{equation}  
    587606\subsubsection{The flux gradient model} 
    588607The flux-gradient relationships used in the OSMOSIS scheme take the form, 
Note: See TracChangeset for help on using the changeset viewer.