<p><b>ringler@lanl.gov</b> 2012-01-05 12:39:29 -0700 (Thu, 05 Jan 2012)</p><p><br>
added option to impose a linear (-gamma * u) tendency term to the RHS of the velocity equation.<br>
<br>
this can be used to smooth out the strong adjustment process resulting from cold starts.<br>
<br>
to use, add the following to the namelist.input (under hmix)<br>
<br>
config_rayleigh_friction = .true.<br>
config_rayleigh_damping_coeff = 3.0e-4<br>
<br>
the first config_ turns on the linear drag. the second config_ specifies the relaxation time.<br>
<br>
the units of config_rayleigh_damping_coeff are (1/s), so a damping time scale of one hour will have<br>
config_rayleigh_damping_coeff = 2.78e-4<br>
<br>
the option has been tested with a variable resolution (20 to 160 km) grid focused in the North Atlantic<br>
using split-explicit time stepping with dt (baroclinic) = 600.0 and config_rayleigh_damping_coeff = 2.78e-4<br>
</p><hr noshade><pre><font color="gray">Modified: branches/ocean_projects/rayleigh/src/core_ocean/Makefile
===================================================================
--- trunk/mpas/src/core_ocean/Makefile 2012-01-04 22:45:33 UTC (rev 1294)
+++ branches/ocean_projects/rayleigh/src/core_ocean/Makefile 2012-01-05 19:39:29 UTC (rev 1298)
@@ -13,6 +13,7 @@
mpas_ocn_vel_forcing.o \
mpas_ocn_vel_forcing_windstress.o \
mpas_ocn_vel_forcing_bottomdrag.o \
+ mpas_ocn_vel_forcing_rayleigh.o \
mpas_ocn_vel_pressure_grad.o \
mpas_ocn_tracer_vadv.o \
mpas_ocn_tracer_vadv_spline.o \
@@ -35,13 +36,13 @@
mpas_ocn_vmix_coefs_tanh.o \
mpas_ocn_restoring.o \
mpas_ocn_tendency.o \
- mpas_ocn_time_integration.o \
- mpas_ocn_time_integration_rk4.o \
- mpas_ocn_time_integration_split.o \
+ mpas_ocn_time_integration.o \
+ mpas_ocn_time_integration_rk4.o \
+ mpas_ocn_time_integration_split.o \
mpas_ocn_equation_of_state.o \
mpas_ocn_equation_of_state_jm.o \
- mpas_ocn_equation_of_state_linear.o \
- mpas_ocn_global_diagnostics.o
+ mpas_ocn_equation_of_state_linear.o \
+ mpas_ocn_global_diagnostics.o
all: core_hyd
@@ -77,12 +78,14 @@
mpas_ocn_vel_hmix_del4.o:
-mpas_ocn_vel_forcing.o: mpas_ocn_vel_forcing_windstress.o mpas_ocn_vel_forcing_bottomdrag.o
+mpas_ocn_vel_forcing.o: mpas_ocn_vel_forcing_windstress.o mpas_ocn_vel_forcing_bottomdrag.o mpas_ocn_vel_forcing_rayleigh.o
mpas_ocn_vel_forcing_windstress.o:
-mpas_ocn_velforcing_bottomdrag.o:
+mpas_ocn_vel_forcing_bottomdrag.o:
+mpas_ocn_vel_forcing_rayleigh.o:
+
mpas_ocn_vel_coriolis.o:
mpas_ocn_tracer_hadv.o: mpas_ocn_tracer_hadv2.o mpas_ocn_tracer_hadv3.o mpas_ocn_tracer_hadv4.o
Modified: branches/ocean_projects/rayleigh/src/core_ocean/Registry
===================================================================
--- trunk/mpas/src/core_ocean/Registry 2012-01-04 22:45:33 UTC (rev 1294)
+++ branches/ocean_projects/rayleigh/src/core_ocean/Registry 2012-01-05 19:39:29 UTC (rev 1298)
@@ -38,7 +38,7 @@
namelist real split_explicit_ts config_btr_gam2_SSHWt1 1.0
namelist real split_explicit_ts config_btr_gam3_uWt2 1.0
namelist logical split_explicit_ts config_btr_solve_SSH2 false
-namelist logical sw_model config_h_ScaleWithMesh false
+namelist logical hmix config_h_ScaleWithMesh false
namelist real hmix config_h_mom_eddy_visc2 0.0
namelist real hmix config_h_mom_eddy_visc4 0.0
namelist logical hmix config_visc_vorticity_term true
@@ -50,6 +50,8 @@
namelist real hmix config_apvm_upwinding 0.5
namelist logical hmix config_mom_decay false
namelist real hmix config_mom_decay_time 3600.0
+namelist logical hmix config_rayleigh_friction false
+namelist real hmix config_rayleigh_damping_coeff 0.0
namelist character vmix config_vert_visc_type const
namelist character vmix config_vert_diff_type const
namelist logical vmix config_implicit_vertical_mix .true.
Modified: branches/ocean_projects/rayleigh/src/core_ocean/mpas_ocn_vel_forcing.F
===================================================================
--- trunk/mpas/src/core_ocean/mpas_ocn_vel_forcing.F 2012-01-04 22:45:33 UTC (rev 1294)
+++ branches/ocean_projects/rayleigh/src/core_ocean/mpas_ocn_vel_forcing.F 2012-01-05 19:39:29 UTC (rev 1298)
@@ -19,6 +19,7 @@
use ocn_vel_forcing_windstress
use ocn_vel_forcing_bottomdrag
+ use ocn_vel_forcing_rayleigh
implicit none
private
@@ -114,7 +115,7 @@
!
!-----------------------------------------------------------------
- integer :: err1, err2
+ integer :: err1, err2, err3
!-----------------------------------------------------------------
!
@@ -126,8 +127,10 @@
call ocn_vel_forcing_windstress_tend(grid, u_src, h_edge, tend, err1)
call ocn_vel_forcing_bottomdrag_tend(grid, u, ke_edge, h_edge, tend, err2)
+ call ocn_vel_forcing_rayleigh_tend(grid, u, tend, err3)
err = ior(err1, err2)
+ err = ior(err, err3)
!--------------------------------------------------------------------
@@ -161,12 +164,14 @@
integer, intent(out) :: err !< Output: error flag
- integer :: err1, err2
+ integer :: err1, err2, err3
call ocn_vel_forcing_windstress_init(err1)
call ocn_vel_forcing_bottomdrag_init(err2)
+ call ocn_vel_forcing_rayleigh_init(err3)
err = ior(err1, err2)
+ err = ior(err, err3)
!--------------------------------------------------------------------
Added: branches/ocean_projects/rayleigh/src/core_ocean/mpas_ocn_vel_forcing_rayleigh.F
===================================================================
--- branches/ocean_projects/rayleigh/src/core_ocean/mpas_ocn_vel_forcing_rayleigh.F (rev 0)
+++ branches/ocean_projects/rayleigh/src/core_ocean/mpas_ocn_vel_forcing_rayleigh.F 2012-01-05 19:39:29 UTC (rev 1298)
@@ -0,0 +1,183 @@
+!|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
+!
+! ocn_vel_forcing_rayleigh
+!
+!> \brief MPAS ocean Rayleigh Friction (to be used to smooth "shocks" from cold starts)
+!> \author Doug Jacobsen
+!> \date 16 September 2011
+!> \version SVN:$Id:$
+!> \details
+!> This module contains the routine for computing
+!> tendencies based on linear Rayleigh friction.
+!
+!-----------------------------------------------------------------------
+
+module ocn_vel_forcing_rayleigh
+
+ use mpas_grid_types
+ use mpas_configure
+
+ implicit none
+ private
+ save
+
+ !--------------------------------------------------------------------
+ !
+ ! Public parameters
+ !
+ !--------------------------------------------------------------------
+
+ !--------------------------------------------------------------------
+ !
+ ! Public member functions
+ !
+ !--------------------------------------------------------------------
+
+ public :: ocn_vel_forcing_rayleigh_tend, &
+ ocn_vel_forcing_rayleigh_init
+
+ !--------------------------------------------------------------------
+ !
+ ! Private module variables
+ !
+ !--------------------------------------------------------------------
+
+ logical :: rayleighFrictionOn
+ real (kind=RKIND) :: rayleighDampingCoef
+
+
+!***********************************************************************
+
+contains
+
+!***********************************************************************
+!
+! routine ocn_vel_forcing_rayleigh_tend
+!
+!> \brief Computes tendency term from Rayleigh friction
+!> \author Doug Jacobsen
+!> \date 15 September 2011
+!> \version SVN:$Id$
+!> \details
+!> This routine computes the Rayleigh friction tendency for momentum
+!> based on current state.
+!
+!-----------------------------------------------------------------------
+
+ subroutine ocn_vel_forcing_rayleigh_tend(grid, u, tend, err)!{{{
+
+ !-----------------------------------------------------------------
+ !
+ ! input variables
+ !
+ !-----------------------------------------------------------------
+
+ real (kind=RKIND), dimension(:,:), intent(in) :: &
+ u !< Input: velocity
+
+ type (mesh_type), intent(in) :: &
+ grid !< Input: grid information
+
+ !-----------------------------------------------------------------
+ !
+ ! input/output variables
+ !
+ !-----------------------------------------------------------------
+
+ real (kind=RKIND), dimension(:,:), intent(inout) :: &
+ tend !< Input/Output: velocity tendency
+
+ !-----------------------------------------------------------------
+ !
+ ! output variables
+ !
+ !-----------------------------------------------------------------
+
+ integer, intent(out) :: err !< Output: error flag
+
+ !-----------------------------------------------------------------
+ !
+ ! local variables
+ !
+ !-----------------------------------------------------------------
+
+ integer :: iEdge, nEdgesSolve, k
+ integer, dimension(:), pointer :: maxLevelEdgeTop
+
+ !-----------------------------------------------------------------
+ !
+ ! call relevant routines for computing tendencies
+ ! note that the user can choose multiple options and the
+ ! tendencies will be added together
+ !
+ !-----------------------------------------------------------------
+
+ err = 0
+
+ if(.not.rayleighFrictionOn) return
+
+ nEdgesSolve = grid % nEdgesSolve
+ maxLevelEdgeTop => grid % maxLevelEdgeTop % array
+
+ do iEdge=1,grid % nEdgesSolve
+
+ do k=1,maxLevelEdgeTop(iEdge)
+
+ tend(k,iEdge) = tend(k,iEdge) &
+ -rayleighDampingCoef*u(k,iEdge)
+
+ enddo
+
+ enddo
+
+
+ !--------------------------------------------------------------------
+
+ end subroutine ocn_vel_forcing_rayleigh_tend!}}}
+
+!***********************************************************************
+!
+! routine ocn_vel_forcing_rayleigh_init
+!
+!> \brief Initializes ocean Rayleigh friction
+!> \author Doug Jacobsen
+!> \date 16 September 2011
+!> \version SVN:$Id$
+!> \details
+!> This routine initializes quantities related to
+!> in the ocean.
+!
+!-----------------------------------------------------------------------
+
+ subroutine ocn_vel_forcing_rayleigh_init(err)!{{{
+
+ !--------------------------------------------------------------------
+
+ !-----------------------------------------------------------------
+ !
+ ! call individual init routines for each parameterization
+ !
+ !-----------------------------------------------------------------
+
+ integer, intent(out) :: err !< Output: error flag
+
+
+ err = 0
+
+ rayleighDampingCoef = 0.0
+
+ if (config_rayleigh_friction) then
+ rayleighFrictionOn = .true.
+ rayleighDampingCoef = config_rayleigh_damping_coeff
+ endif
+
+ !--------------------------------------------------------------------
+
+ end subroutine ocn_vel_forcing_rayleigh_init!}}}
+
+!***********************************************************************
+
+end module ocn_vel_forcing_rayleigh
+
+!|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
+! vim: foldmethod=marker
</font>
</pre>