Merge branch 'jonbob/ocn/add-akt-tilt-coupling' into next (PR #1278)

Modifications needed for time filtered ssh gradient coupling This PR adds changes needed to the ocean core to allow filtering of high frequency modes from sea surface tilt. It includes modifications to the ocn driver as well as the mpas-o model itself: * Added a new namelist option specifying the filtering timescale * Added a new set of variables to registry that are the filtered ssh gradient It incorporates MPAS PR 1245. This PR will change answers for all compsets with active ocean. Tested to be BFB when the new namelist option, config_ssh_grad_relax_timescale, is set to 0.0. But also tested to have the expected impact in ongoing T62-oRRS18to6 GMPAS simulation. [NML] [non-BFB]
E3SM-Project · Feb 21, 2017 · 80ff3aa · 80ff3aa
2 parents 1e30505 + 24cdc59
commit 80ff3aa
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diff --git a/components/mpas-o/bld/build-namelist b/components/mpas-o/bld/build-namelist
@@ -671,6 +671,12 @@ add_default($nl, 'config_use_bulk_thickness_flux');
 add_default($nl, 'config_flux_attenuation_coefficient');
 add_default($nl, 'config_flux_attenuation_coefficient_runoff');
 
+############################
+# Namelist group: coupling #
+############################
+
+add_default($nl, 'config_ssh_grad_relax_timescale');
+
 ######################################
 # Namelist group: shortwaveRadiation #
 ######################################
@@ -1794,6 +1800,7 @@ my @groups = qw(run_modes
                 vmix_tanh
                 cvmix
                 forcing
+                coupling
                 shortwaveradiation
                 frazil_ice
                 land_ice_fluxes

diff --git a/components/mpas-o/bld/build-namelist-group-list b/components/mpas-o/bld/build-namelist-group-list
@@ -23,6 +23,7 @@ my @groups = qw(run_modes
                 vmix_tanh
                 cvmix
                 forcing
+                coupling
                 shortwaveradiation
                 frazil_ice
                 land_ice_fluxes

diff --git a/components/mpas-o/bld/build-namelist-section b/components/mpas-o/bld/build-namelist-section
@@ -258,6 +258,12 @@ add_default($nl, 'config_use_bulk_thickness_flux');
 add_default($nl, 'config_flux_attenuation_coefficient');
 add_default($nl, 'config_flux_attenuation_coefficient_runoff');
 
+############################
+# Namelist group: coupling #
+############################
+
+add_default($nl, 'config_ssh_grad_relax_timescale');
+
 ######################################
 # Namelist group: shortwaveRadiation #
 ######################################

diff --git a/components/mpas-o/bld/namelist_files/namelist_defaults_mpas-o.xml b/components/mpas-o/bld/namelist_files/namelist_defaults_mpas-o.xml
@@ -227,6 +227,9 @@
 <config_flux_attenuation_coefficient>0.001</config_flux_attenuation_coefficient>
 <config_flux_attenuation_coefficient_runoff>10.0</config_flux_attenuation_coefficient_runoff>
 
+<!-- coupling -->
+<config_ssh_grad_relax_timescale>86400.0</config_ssh_grad_relax_timescale>
+
 <!-- shortwaveRadiation -->
 <config_sw_absorption_type>'jerlov'</config_sw_absorption_type>
 <config_jerlov_water_type>3</config_jerlov_water_type>

diff --git a/components/mpas-o/bld/namelist_files/namelist_definition_mpas-o.xml b/components/mpas-o/bld/namelist_files/namelist_definition_mpas-o.xml
@@ -1157,6 +1157,17 @@ Default: Defined in namelist_defaults.xml
 </entry>
 
 
+<!-- coupling -->
+
+<entry id="config_ssh_grad_relax_timescale" type="real"
+	category="coupling" group="coupling">
+Timescale for relaxation of the ssh gradient for coupling. A value of 0.0 removes any relaxation and gives instantaneous response.
+
+Valid values: Any positive real number.
+Default: Defined in namelist_defaults.xml
+</entry>
+
+
 <!-- shortwaveRadiation -->
 
 <entry id="config_sw_absorption_type" type="char*1024"

diff --git a/components/mpas-o/driver/ocn_comp_mct.F b/components/mpas-o/driver/ocn_comp_mct.F
@@ -1884,6 +1884,7 @@ subroutine ocn_export_mct(o2x_o, errorCode)   !{{{
    integer, dimension(:), pointer :: landIceMask
 
    real (kind=RKIND), dimension(:), pointer :: seaIceEnergy, accumulatedFrazilIceMass, frazilSurfacePressure, &
+                                               filteredSSHGradientZonal, filteredSSHGradientMeridional, &
                                                CO2Flux, DMSFlux, surfaceUpwardCO2Flux, &
                                                avgOceanSurfaceDIC, &
                                                avgOceanSurfaceDON, &
@@ -1908,8 +1909,17 @@ subroutine ocn_export_mct(o2x_o, errorCode)   !{{{
                        config_use_DMSTracers_sea_ice_coupling,  &
                        config_use_MacroMoleculesTracers_sea_ice_coupling
 
+   real(kind=RKIND), pointer :: &
+        config_ssh_grad_relax_timescale
+
+   real(kind=RKIND) :: &
+        timeFilterFactor
+
    logical :: keepFrazil
 
+   ! flag to check if this is the first export to allow setting of relaxed coupling variables.
+   logical :: firstExport = .true.
+
    errorcode = 0
 
    ! get configure options
@@ -1923,6 +1933,8 @@ subroutine ocn_export_mct(o2x_o, errorCode)   !{{{
                                                 config_use_DMSTracers_sea_ice_coupling)
    call mpas_pool_get_config(domain % configs, 'config_use_MacroMoleculesTracers_sea_ice_coupling',  &
                                                 config_use_MacroMoleculesTracers_sea_ice_coupling)
+   call mpas_pool_get_config(domain % configs, 'config_ssh_grad_relax_timescale', &
+                                                config_ssh_grad_relax_timescale)
 
    n = 0
    block_ptr => domain % blocklist
@@ -1948,6 +1960,8 @@ subroutine ocn_export_mct(o2x_o, errorCode)   !{{{
      call mpas_pool_get_array(forcingPool, 'avgTracersSurfaceValue', avgTracersSurfaceValue)
      call mpas_pool_get_array(forcingPool, 'avgSurfaceVelocity', avgSurfaceVelocity)
      call mpas_pool_get_array(forcingPool, 'avgSSHGradient', avgSSHGradient)
+     call mpas_pool_get_array(forcingPool, 'filteredSSHGradientZonal', filteredSSHGradientZonal)
+     call mpas_pool_get_array(forcingPool, 'filteredSSHGradientMeridional', filteredSSHGradientMeridional)
      if ( frazilIceActive ) then
         call mpas_pool_get_array(forcingPool, 'seaIceEnergy', seaIceEnergy)
         call mpas_pool_get_array(forcingPool, 'frazilSurfacePressure', frazilSurfacePressure)
@@ -1983,6 +1997,27 @@ subroutine ocn_export_mct(o2x_o, errorCode)   !{{{
 !    call mpas_pool_get_array(forcingPool, 'DMSFlux', DMSFlux)
 !    call mpas_pool_get_array(forcingPool, 'surfaceUpwardCO2Flux', surfaceUpwardCO2Flux)
 
+     ! time filter ssh gradient
+     if (firstExport .and. trim(runtype) == "initial") then
+        filteredSSHGradientZonal     = avgSSHGradient(index_avgZonalSSHGradient,     :)
+        filteredSSHGradientMeridional = avgSSHGradient(index_avgMeridionalSSHGradient, :)
+        firstExport = .false.
+     else
+
+        if (config_ssh_grad_relax_timescale < real(ocn_cpl_dt,RKIND)) then
+           timeFilterFactor = 1.0_RKIND
+        else
+           timeFilterFactor = real(ocn_cpl_dt,RKIND) / config_ssh_grad_relax_timescale
+        endif
+
+        filteredSSHGradientZonal = filteredSSHGradientZonal * (1.0_RKIND - timeFilterFactor) + &
+             avgSSHGradient(index_avgZonalSSHGradient, :) * timeFilterFactor
+
+        filteredSSHGradientMeridional = filteredSSHGradientMeridional * (1.0_RKIND - timeFilterFactor) + &
+             avgSSHGradient(index_avgMeridionalSSHGradient, :) * timeFilterFactor
+
+     endif
+
      do i = 1, nCellsSolve
        n = n + 1
 
@@ -1991,8 +2026,8 @@ subroutine ocn_export_mct(o2x_o, errorCode)   !{{{
        o2x_o % rAttr(index_o2x_So_u, n) = avgSurfaceVelocity(index_avgZonalSurfaceVelocity, i)
        o2x_o % rAttr(index_o2x_So_v, n) = avgSurfaceVelocity(index_avgMeridionalSurfaceVelocity, i)
 
-       o2x_o % rAttr(index_o2x_So_dhdx, n) = avgSSHGradient(index_avgZonalSSHGradient, i)
-       o2x_o % rAttr(index_o2x_So_dhdy, n) = avgSSHGradient(index_avgMeridionalSSHGradient, i)
+       o2x_o % rAttr(index_o2x_So_dhdx, n) = filteredSSHGradientZonal(i)
+       o2x_o % rAttr(index_o2x_So_dhdy, n) = filteredSSHGradientMeridional(i)
        if ( frazilIceActive ) then
           ! negative when frazil ice can be melted
           keepFrazil = .true.

diff --git a/components/mpas-o/model b/components/mpas-o/model