.. _doc.coupling.dvpers:

**Developper's corner**
=======================

**WW3 informations** 
--------------------

-  To add a module, change

   | link
   | comp
   | modww3_mpi


- WW3 structure

::

   +====================+===============+====================================+
   | ww3_shel.ftn       | main program  |                                    |
   +--------------------+---------------+------------------------------------+
   | w3wavemd.ftn       | subroutine    | time integration of wave variables |
   +--------------------+---------------+------------------------------------+
   | w3iogomd.ftn       | subroutine    | IO                                 |
   +--------------------+---------------+------------------------------------+
   | w3oacpmd.ftn       | subroutine    | OASIS main routine                 |
   +--------------------+---------------+------------------------------------+
   | w3ogcmmd.ftn       | subroutine    | OASIS coupling with MARS           |
   +====================+===============+====================================+


- WW3 variables

::

   +====================+===================================+================+===================+
   | Variable Name      | Signification                     | Assigned in    | spatial extension |
   +====================+===================================+================+===================+
   | WLV                | Sea surface Height (m)            |                | NSEA              |
   +--------------------+-----------------------------------+----------------+-------------------+
   | CX                 | Oceanic current u-component (m/s) |                | 0:NSEA (CX(0)=0)  |
   +--------------------+-----------------------------------+----------------+-------------------+
   | CY                 | Oceanic current v-component (m/s) |                | 0:NSEA (CY(0)=0)  |
   +--------------------+-----------------------------------+----------------+-------------------+
   | T0M1               | Mean wave period (s)              |                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | HS                 | Wave height (hs in m)             |                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | THM                | Mean wave direction (degrees)     |                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | BHD                | Wave-induced Bernoulli head       |                | NSEALM            |
   |                    | pressure (N.m-1) (J term)         |                |                   |
   +--------------------+-----------------------------------+----------------+-------------------+
   | TAUOX              | Wave-ocean momentum flux (m2.s-2) |                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | TAUOY              | Wave-ocean momentum flux (m2.s-2) |                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | UBA                | Bottom rms velocity (m/s)         |                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | PHIOC              | Wave-to-ocean TKE flux (W.m-2)    |                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | TAUWIX             | Net wave-supported stress (m2.s-2)|                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | TAUWIY             | Net wave-supported stress (m2.s-2)|                | NSEALM            |
   +--------------------+-----------------------------------+----------------+-------------------+
   | WLM                | Mean wave length (m)              |                | NSEALM            |
   +====================+===================================+================+===================+


- Note on the MPI decomposition domain

    Each cpu increments on its own domain::

        DO JSEA=1, NSEAL
          !/DIST            ISEA   = IAPROC + (JSEA-1)*NAPROC
          !/SHRD            ISEA   = JSEA
                   WLV(ISEA) = TMP(JSEA)
                   CX(ISEA) = TMP(JSEA)
                   CY(ISEA) = TMP(JSEA)




.. note::

   NSEA + land cells = NY*NX    (open boundaries are included into NSEA variable)
   NSEAL : number of wet cells covered by the CPU domain
   NSEALM : maximum of NSEAL

   (imin+1,jmin+1) on MARS grid == (2,2) on WW3 grid