Chapter 6: Adaptive grid refinement

6.1 Parameters of adaptive refinement

Example

Call Agrif_Set_Regridding(30)

Call Agrif_Set_Minwidth(18)

Call Agrif_Set_Rafmax(3)

6.2 Refinement Criterion

Agrif_Detect

Agrif_Detect(taberr,size_taberr) is a users subroutine.

taberr = 1

Where error is detected, taberr values are located at grid cell corners of the reference grid (including boundaries)

Example:

SUBROUTINE Agrif_Detect(taberr,sizexy)

        implicit none

        # include "ocean2d.h"

        Integer, Dimension(2) :: sizexy

        Integer,Dimension(sizexy(1),sizexy(2)) :: taberr

        real vort(GLOBAL_2D_ARRAY)

        do j=1,Mm+1

                do i=1,Lm+1

                        vort(i,j) = (v(i,j)-v(i-1,j))-(u(i,j)-u(i,j-1))

                enddo

        enddo

        crit = maxval(abs(vort))

        taberr=0

        where abs(vort)>0.8*crit

                taberr=1

        end where

End Subroutine Agrif_detect

Note

• Agrif_Detect() has to be written even without adaptive mesh refinement

6.3 Variable restoring

Restoring of grid variable from one grid hierarchy to another

1. Declaration

Call Agrif_Declare_Variable(...,variable_id,restore=.true.)

2. Specify what to restore

Agrif_Before_Regridding() , Agrif_Save_ForRestore()

Example: Call Agrif_Declare_Variable(...,zeta_id,restore=.true.)

Subroutine Agrif_Before_Regridding()

        #include "ocean2d.h"

        Call Agrif_Save_ForRestore(Zt_avg1,zeta_id)

End Subroutine Agrif_Before_Regridding

Note

• Agrif_Before_Regridding() has to be written even without adaptive mesh refinement.