Merge branch 'vanroekel/ocean/add-submesoscale-eddies' (PR #5099)

Adds submesoscale parameterization for mpas-ocean

Adds the Fox-Kemper et al 2011 parameterization for submesocale eddies.
There is also a substantial eddy parameterization reorganization as the
buoyancy gradient that was calculated within GM is also needed for this
parameterization. There are also cases when we will run with the
submeso parameterization and not GM so that calculation is separate.
The density threshold MLD is also removed from the analysis member as it
is required by numerous calculations in the forward model now.

The contributions of submesoscale eddy velocity to AMOC is also added to
the MOC streamfunction computation.

[NML]
[BFB] - stealth feature not turned on by default

components/mpas-ocean/bld/build-namelist

@@ -568,6 +568,16 @@ add_default($nl, 'config_Redi_horizontal_taper');
 add_default($nl, 'config_Redi_horizontal_ramp_min');
 add_default($nl, 'config_Redi_horizontal_ramp_max');
 
+######################################################
+# Namelist group: submesoscale_eddy_parameterization #
+######################################################
+
+add_default($nl, 'config_submesoscale_enable');
+add_default($nl, 'config_submesoscale_tau');
+add_default($nl, 'config_submesoscale_Ce');
+add_default($nl, 'config_submesoscale_Lfmin');
+add_default($nl, 'config_submesoscale_ds_max');
+
 ############################################
 # Namelist group: GM_eddy_parameterization #
 ############################################
@@ -592,6 +602,15 @@ add_default($nl, 'config_GM_horizontal_ramp_max');
 add_default($nl, 'config_GMRedi_Rossby_ramp_min');
 add_default($nl, 'config_GMRedi_Rossby_ramp_max');
 
+#########################################
+# Namelist group: eddy_parameterization #
+#########################################
+
+add_default($nl, 'config_eddyMLD_dens_threshold');
+add_default($nl, 'config_eddyMLD_reference_depth');
+add_default($nl, 'config_eddyMLD_reference_pressure');
+add_default($nl, 'config_eddyMLD_use_old');
+
 ####################################
 # Namelist group: Rayleigh_damping #
 ####################################
@@ -1291,9 +1310,7 @@ add_default($nl, 'config_AM_mixedLayerDepths_output_stream');
 add_default($nl, 'config_AM_mixedLayerDepths_write_on_startup');
 add_default($nl, 'config_AM_mixedLayerDepths_compute_on_startup');
 add_default($nl, 'config_AM_mixedLayerDepths_Tthreshold');
-add_default($nl, 'config_AM_mixedLayerDepths_Dthreshold');
 add_default($nl, 'config_AM_mixedLayerDepths_crit_temp_threshold');
-add_default($nl, 'config_AM_mixedLayerDepths_crit_dens_threshold');
 add_default($nl, 'config_AM_mixedLayerDepths_reference_pressure');
 add_default($nl, 'config_AM_mixedLayerDepths_Tgradient');
 add_default($nl, 'config_AM_mixedLayerDepths_Dgradient');
@@ -1681,7 +1698,9 @@ my @groups = qw(run_modes
                 hmix_del4
                 hmix_leith
                 redi_isopycnal_mixing
+                submesoscale_eddy_parameterization
                 gm_eddy_parameterization
+                eddy_parameterization
                 rayleigh_damping
                 cvmix
                 gotm

components/mpas-ocean/bld/build-namelist-group-list

@@ -9,7 +9,9 @@ my @groups = qw(run_modes
                 hmix_del4
                 hmix_leith
                 redi_isopycnal_mixing
+                submesoscale_eddy_parameterization
                 gm_eddy_parameterization
+                eddy_parameterization
                 rayleigh_damping
                 cvmix
                 gotm

components/mpas-ocean/bld/build-namelist-section

@@ -111,6 +111,16 @@ add_default($nl, 'config_Redi_horizontal_taper');
 add_default($nl, 'config_Redi_horizontal_ramp_min');
 add_default($nl, 'config_Redi_horizontal_ramp_max');
 
+######################################################
+# Namelist group: submesoscale_eddy_parameterization #
+######################################################
+
+add_default($nl, 'config_submesoscale_enable');
+add_default($nl, 'config_submesoscale_tau');
+add_default($nl, 'config_submesoscale_Ce');
+add_default($nl, 'config_submesoscale_Lfmin');
+add_default($nl, 'config_submesoscale_ds_max');
+
 ############################################
 # Namelist group: GM_eddy_parameterization #
 ############################################
@@ -135,6 +145,15 @@ add_default($nl, 'config_GM_horizontal_ramp_max');
 add_default($nl, 'config_GMRedi_Rossby_ramp_min');
 add_default($nl, 'config_GMRedi_Rossby_ramp_max');
 
+#########################################
+# Namelist group: eddy_parameterization #
+#########################################
+
+add_default($nl, 'config_eddyMLD_dens_threshold');
+add_default($nl, 'config_eddyMLD_reference_depth');
+add_default($nl, 'config_eddyMLD_reference_pressure');
+add_default($nl, 'config_eddyMLD_use_old');
+
 ####################################
 # Namelist group: Rayleigh_damping #
 ####################################
@@ -763,9 +782,7 @@ add_default($nl, 'config_AM_mixedLayerDepths_output_stream');
 add_default($nl, 'config_AM_mixedLayerDepths_write_on_startup');
 add_default($nl, 'config_AM_mixedLayerDepths_compute_on_startup');
 add_default($nl, 'config_AM_mixedLayerDepths_Tthreshold');
-add_default($nl, 'config_AM_mixedLayerDepths_Dthreshold');
 add_default($nl, 'config_AM_mixedLayerDepths_crit_temp_threshold');
-add_default($nl, 'config_AM_mixedLayerDepths_crit_dens_threshold');
 add_default($nl, 'config_AM_mixedLayerDepths_reference_pressure');
 add_default($nl, 'config_AM_mixedLayerDepths_Tgradient');
 add_default($nl, 'config_AM_mixedLayerDepths_Dgradient');

components/mpas-ocean/bld/namelist_files/namelist_defaults_mpaso.xml

@@ -152,6 +152,13 @@
 <config_Redi_horizontal_ramp_max>30e3</config_Redi_horizontal_ramp_max>
 <config_Redi_horizontal_ramp_max ocn_grid="WCAtl12to45E2r4">40e3</config_Redi_horizontal_ramp_max>
 
+<!-- submesoscale_eddy_parameterization -->
+<config_submesoscale_enable>.false.</config_submesoscale_enable>
+<config_submesoscale_tau>172800</config_submesoscale_tau>
+<config_submesoscale_Ce>0.06</config_submesoscale_Ce>
+<config_submesoscale_Lfmin>1000.0</config_submesoscale_Lfmin>
+<config_submesoscale_ds_max>100000.0</config_submesoscale_ds_max>
+
 <!-- GM_eddy_parameterization -->
 <config_use_GM>.true.</config_use_GM>
 <config_use_GM ocn_grid="oRRS30to10v3">.false.</config_use_GM>
@@ -191,6 +198,12 @@
 <config_GMRedi_Rossby_ramp_min>0.5</config_GMRedi_Rossby_ramp_min>
 <config_GMRedi_Rossby_ramp_max>3.0</config_GMRedi_Rossby_ramp_max>
 
+<!-- eddy_parameterization -->
+<config_eddyMLD_dens_threshold>0.03</config_eddyMLD_dens_threshold>
+<config_eddyMLD_reference_depth>10</config_eddyMLD_reference_depth>
+<config_eddyMLD_reference_pressure>1.0e5</config_eddyMLD_reference_pressure>
+<config_eddyMLD_use_old>.true.</config_eddyMLD_use_old>
+
 <!-- Rayleigh_damping -->
 <config_Rayleigh_friction>.false.</config_Rayleigh_friction>
 <config_Rayleigh_damping_coeff>0.0</config_Rayleigh_damping_coeff>
@@ -725,9 +738,7 @@
 <config_AM_mixedLayerDepths_write_on_startup>.false.</config_AM_mixedLayerDepths_write_on_startup>
 <config_AM_mixedLayerDepths_compute_on_startup>.true.</config_AM_mixedLayerDepths_compute_on_startup>
 <config_AM_mixedLayerDepths_Tthreshold>.true.</config_AM_mixedLayerDepths_Tthreshold>
-<config_AM_mixedLayerDepths_Dthreshold>.true.</config_AM_mixedLayerDepths_Dthreshold>
 <config_AM_mixedLayerDepths_crit_temp_threshold>0.2</config_AM_mixedLayerDepths_crit_temp_threshold>
-<config_AM_mixedLayerDepths_crit_dens_threshold>0.03</config_AM_mixedLayerDepths_crit_dens_threshold>
 <config_AM_mixedLayerDepths_reference_pressure>1.0E5</config_AM_mixedLayerDepths_reference_pressure>
 <config_AM_mixedLayerDepths_Tgradient>.false.</config_AM_mixedLayerDepths_Tgradient>
 <config_AM_mixedLayerDepths_Dgradient>.false.</config_AM_mixedLayerDepths_Dgradient>

components/mpas-ocean/bld/namelist_files/namelist_definition_mpaso.xml

@@ -499,6 +499,49 @@ Default: Defined in namelist_defaults.xml
 </entry>
 
 
+<!-- submesoscale_eddy_parameterization -->
+
+<entry id="config_submesoscale_enable" type="logical"
+	category="submesoscale_eddy_parameterization" group="submesoscale_eddy_parameterization">
+flag to enable the FK2011 parameterization for submesoscale eddies
+
+Valid values: .true. or .false.
+Default: Defined in namelist_defaults.xml
+</entry>
+
+<entry id="config_submesoscale_tau" type="real"
+	category="submesoscale_eddy_parameterization" group="submesoscale_eddy_parameterization">
+timescale for frictional slumping of front (in seconds)
+
+Valid values: positive reals, between 1-10 days
+Default: Defined in namelist_defaults.xml
+</entry>
+
+<entry id="config_submesoscale_Ce" type="real"
+	category="submesoscale_eddy_parameterization" group="submesoscale_eddy_parameterization">
+efficiency of submesoscale eddies
+
+Valid values: 0.06 - 0.08
+Default: Defined in namelist_defaults.xml
+</entry>
+
+<entry id="config_submesoscale_Lfmin" type="real"
+	category="submesoscale_eddy_parameterization" group="submesoscale_eddy_parameterization">
+minimum frontal width (meters)
+
+Valid values: between 200 and 5000m
+Default: Defined in namelist_defaults.xml
+</entry>
+
+<entry id="config_submesoscale_ds_max" type="real"
+	category="submesoscale_eddy_parameterization" group="submesoscale_eddy_parameterization">
+maximum grid scale to scale up buoyancy gradient
+
+Valid values: around 1 degree
+Default: Defined in namelist_defaults.xml
+</entry>
+
+
 <!-- GM_eddy_parameterization -->
 
 <entry id="config_use_GM" type="logical"
@@ -654,6 +697,41 @@ Default: Defined in namelist_defaults.xml
 </entry>
 
 
+<!-- eddy_parameterization -->
+
+<entry id="config_eddyMLD_dens_threshold" type="real"
+	category="eddy_parameterization" group="eddy_parameterization">
+potential density change relative to surface for mixed layer depth threshold method.  This calculation is used for the Redi tapering, GM N2_dependent bolus kappa, and the submesoscale eddy parameterization
+
+Valid values: suggested range 0.01 less than or equal to thresh less than or equal to 0.5
+Default: Defined in namelist_defaults.xml
+</entry>
+
+<entry id="config_eddyMLD_reference_depth" type="real"
+	category="eddy_parameterization" group="eddy_parameterization">
+reference depth for threshold computation
+
+Valid values: any positive real, near 10
+Default: Defined in namelist_defaults.xml
+</entry>
+
+<entry id="config_eddyMLD_reference_pressure" type="real"
+	category="eddy_parameterization" group="eddy_parameterization">
+reference pressure for original mixed layer depth calculation
+
+Valid values: positive reals around 1.0e5
+Default: Defined in namelist_defaults.xml
+</entry>
+
+<entry id="config_eddyMLD_use_old" type="logical"
+	category="eddy_parameterization" group="eddy_parameterization">
+switches from old dThreshMLD calculation to new (fixed one)
+
+Valid values: .true. or .false.
+Default: Defined in namelist_defaults.xml
+</entry>
+
+
 <!-- Rayleigh_damping -->
 
 <entry id="config_Rayleigh_friction" type="logical"
@@ -4020,14 +4098,6 @@ Valid values: .true. or .false.
 Default: Defined in namelist_defaults.xml
 </entry>
 
-<entry id="config_AM_mixedLayerDepths_Dthreshold" type="logical"
-	category="AM_mixedLayerDepths" group="AM_mixedLayerDepths">
-Logical flag that determines if MLDs are calculated using a critical density threshold
-
-Valid values: .true. or .false.
-Default: Defined in namelist_defaults.xml
-</entry>
-
 <entry id="config_AM_mixedLayerDepths_crit_temp_threshold" type="real"
 	category="AM_mixedLayerDepths" group="AM_mixedLayerDepths">
 temperature change relative to surface for threshold method
@@ -4036,14 +4106,6 @@ Valid values: all real positive values, suggested range 0.2 less than or equal t
 Default: Defined in namelist_defaults.xml
 </entry>
 
-<entry id="config_AM_mixedLayerDepths_crit_dens_threshold" type="real"
-	category="AM_mixedLayerDepths" group="AM_mixedLayerDepths">
-potential density change relative to surface for threshold method
-
-Valid values: suggested range 0.01 less than or equal to thresh less than or equal to 0.5
-Default: Defined in namelist_defaults.xml
-</entry>
-
 <entry id="config_AM_mixedLayerDepths_reference_pressure" type="real"
 	category="AM_mixedLayerDepths" group="AM_mixedLayerDepths">
 reference pressure for threshold computation

components/mpas-ocean/cime_config/buildnml

@@ -1125,6 +1125,8 @@ def buildnml(case, caseroot, compname):
             lines.append('    <var name="mocStreamvalLatAndDepthGM"/>')
             lines.append('    <var name="mocStreamvalLatAndDepthRegionGM"/>')
 
+        lines.append('    <var name="mocStreamvalLatAndDepthMLE"/>')
+        lines.append('    <var name="mocStreamvalLatAndDepthRegionMLE"/>')
         lines.append('    <var_struct name="tracersSurfaceFlux"/>')
         lines.append('    <var name="penetrativeTemperatureFlux"/>')
         lines.append('    <var name="latentHeatFlux"/>')

components/mpas-ocean/driver/ocn_comp_mct.F

@@ -60,6 +60,8 @@ module ocn_comp_mct
    use ocn_tracer_surface_restoring
    use ocn_gm
    use ocn_config
+   use ocn_submesoscale_eddies
+   use ocn_eddy_parameterization_helpers
 !
 ! !PUBLIC MEMBER FUNCTIONS:
   implicit none
@@ -971,6 +973,16 @@ subroutine ocn_run_mct( EClock, cdata_o, x2o_o, o2x_o)!{{{
 
             call ocn_frazil_forcing_build_arrays(domain, meshPool, forcingPool, statePool, ierr)
 
+            call ocn_eddy_compute_mixed_layer_depth(statePool, forcingPool)
+            if (config_use_GM .or. config_submesoscale_enable) then
+                call ocn_eddy_compute_buoyancy_gradient()
+            end if
+
+            if (config_submesoscale_enable) then
+                call mpas_timer_start("submesoscale eddy velocity compute", .false.)
+                call ocn_submesoscale_compute_velocity()
+                call mpas_timer_stop("submesoscale eddy velocity compute")
+            end if
             ! Compute normalGMBolusVelocity, relativeSlope and RediDiffVertCoef if respective flags are turned on
             if (config_use_Redi.or.config_use_GM) then
               call ocn_gm_compute_Bolus_velocity(statePool, meshPool, scratchPool, timeLevelIn=1)