Merge branch 'beydoun/new_cld_frac_r_default' (PR E3SM-Project#7412)

New settings for EAMxx at various resolutions as decided by group's evaluation.

[non-BFB]
[CC]

Author: tcclevenger

components/eamxx/cime_config/namelist_defaults_eamxx.xml

@@ -216,17 +216,20 @@ be lost if SCREAM_HACK_XML is not enabled.
         ${DIN_LOC_ROOT}/atm/scream/tables/vm_table_vals_v2.dat8
       </tables>
       <autoconversion_prefactor type="real" doc="Autoconversion linear prefactor">1350.0</autoconversion_prefactor>
+      <autoconversion_prefactor hgrid="ne256np4.pg2">2700.0</autoconversion_prefactor>
       <autoconversion_qc_exponent type="real" doc="Autoconversion qc exponent">2.47</autoconversion_qc_exponent>
       <autoconversion_nc_exponent type="real" doc="Autoconversion nc exponent">1.79</autoconversion_nc_exponent>
       <autoconversion_radius type="real" doc="Autoconversion droplet radius in meter">25.0e-6</autoconversion_radius>
       <accretion_prefactor type="real" doc="Accretion linear prefactor">67.0</accretion_prefactor>
+      <accretion_prefactor hgrid="ne256np4.pg2">150.0</accretion_prefactor>
       <accretion_qc_exponent type="real" doc="Accretion qc exponent">1.15</accretion_qc_exponent>
       <accretion_qr_exponent type="real" doc="Accretion qr exponent">1.15</accretion_qr_exponent>
       <rain_selfcollection_prefactor type="real" doc="Rain self-collection prefactor">5.78</rain_selfcollection_prefactor>
       <rain_selfcollection_breakup_diameter type="real" doc="Rain self-collection breakup diameter in meter">0.00028</rain_selfcollection_breakup_diameter>
       <constant_mu_rain type="real" doc="Constant shape parameter (mu) in the rain droplet distribution">1.0</constant_mu_rain>
-      <spa_ccn_to_nc_factor type="real" doc="Scaling factor for turning SPA ccn into P3 nc">1.0</spa_ccn_to_nc_factor>
-      <spa_ccn_to_nc_exponent type="real" doc="Exponent for turning SPA ccn into P3 nc">1.0</spa_ccn_to_nc_exponent>      
+      <spa_ccn_to_nc_factor type="real" doc="Scaling factor for turning SPA ccn into P3 nc">2000.0</spa_ccn_to_nc_factor>
+      <spa_ccn_to_nc_factor hgrid="ne256np4.pg2">1000.0</spa_ccn_to_nc_factor>
+      <spa_ccn_to_nc_exponent type="real" doc="Exponent for turning SPA ccn into P3 nc">0.55</spa_ccn_to_nc_exponent>      
       <cldliq_to_ice_collection_factor type="real" doc="Cloud liquid to ice collection scaling factor">0.5</cldliq_to_ice_collection_factor>
       <rain_to_ice_collection_factor type="real" doc="Rain to ice collection scaling factor">1.0</rain_to_ice_collection_factor>
       <min_rime_rho type="real" doc="Minimum rime density in kg/m3">50.0</min_rime_rho>
@@ -236,8 +239,11 @@ be lost if SCREAM_HACK_XML is not enabled.
       <ice_sedimentation_factor type="real" doc="Ice sedimentation fall speed factor">1.0</ice_sedimentation_factor>
       <do_ice_production type="logical" doc="Flag to turn on ice production processes (loss processes unaffected)">true</do_ice_production>
       <set_cld_frac_l_to_one type="logical" doc="set P3 input liquid cloud fraction to 1 everywhere">false</set_cld_frac_l_to_one>
-      <set_cld_frac_r_to_one type="logical" doc="set P3 input rain cloud fraction to 1 everywhere"  >false</set_cld_frac_r_to_one>
-      <set_cld_frac_i_to_one type="logical" doc="set P3 input ice cloud fraction to 1 everywhere"   >false</set_cld_frac_i_to_one>
+      <set_cld_frac_r_to_one type="logical" doc="set P3 input rain cloud fraction to 1 everywhere">false</set_cld_frac_r_to_one>
+      <set_cld_frac_r_to_one hgrid="ne256np4.pg2">true</set_cld_frac_r_to_one>
+      <set_cld_frac_r_to_one hgrid="ne512np4.pg2">true</set_cld_frac_r_to_one>
+      <set_cld_frac_r_to_one hgrid="ne1024np4.pg2">true</set_cld_frac_r_to_one>
+      <set_cld_frac_i_to_one type="logical" doc="set P3 input ice cloud fraction to 1 everywhere">false</set_cld_frac_i_to_one>
       <use_separate_ice_liq_frac type="logical" doc="use separate ice and liquid cloud fractions from shoc">false</use_separate_ice_liq_frac>
       <extra_p3_diags type="logical" doc="Extra P3 diagnostics">false</extra_p3_diags>
     </p3>

components/eamxx/src/physics/p3/impl/p3_autoconversion_impl.hpp

@@ -28,13 +28,7 @@ ::cloud_water_autoconversion(
       runtime_options.autoconversion_nc_exponent;
   const Scalar autoconversion_radius = runtime_options.autoconversion_radius;
 
-  Scalar CONS3;
-  // TODO: always default to second branch after BFB stuff is addressed
-  if(autoconversion_radius == sp(25.0e-6)) {
-    CONS3 = C::CONS3;
-  } else {
-    CONS3 = sp(1.0) / (C::CONS2 * pow(autoconversion_radius, sp(3.0)));
-  }
+  const Scalar CONS3 = sp(1.0) / (C::CONS2 * pow(autoconversion_radius, sp(3.0)));
 
   if(qc_not_small.any()) {
     Spack sgs_var_coef;

components/eamxx/src/physics/p3/impl/p3_cloud_rain_acc_impl.hpp

@@ -36,17 +36,10 @@ ::cloud_rain_accretion(
   const auto qr_and_qc_not_small = (qr_incld >= qsmall) && (qc_incld >= qsmall) && context;
   if(qr_and_qc_not_small.any()) {
     // Khroutdinov and Kogan (2000)
-    // TODO: always default to second branch after BFB stuff is addressed
-    if(accretion_qc_exponent == accretion_qr_exponent) {
-      qc2qr_accret_tend.set(qr_and_qc_not_small,
-                            sgs_var_coef * accretion_prefactor *
-                                pow(qc_incld * qr_incld, accretion_qr_exponent));
-    } else {
-      qc2qr_accret_tend.set(qr_and_qc_not_small,
-                            sgs_var_coef * accretion_prefactor *
-                                pow(qc_incld, accretion_qc_exponent) *
-                                pow(qr_incld, accretion_qr_exponent));
-    }
+    qc2qr_accret_tend.set(qr_and_qc_not_small,
+                          sgs_var_coef * accretion_prefactor *
+                              pow(qc_incld, accretion_qc_exponent) *
+                              pow(qr_incld, accretion_qr_exponent));
     nc_accret_tend.set(qr_and_qc_not_small,
                        qc2qr_accret_tend * nc_incld / qc_incld);
 

components/eamxx/src/physics/p3/impl/p3_main_impl_part1.hpp

@@ -141,11 +141,8 @@ ::p3_main_part1(
         // and it can be made sublinear (e.g., 2000 and 0.55).
         // First, scale by cld_frac_l to account for subgrid frac (if any)
         auto nccn_scaled = nccn_prescribed(k) / inv_cld_frac_l(k);
-        // TODO: HACK: keep BFB, avoid roundoff diff due to pow(x, 1.0)
-        // Second, apply the exponent, but keep strict BFB with defaults
-        if(spa_ccn_to_nc_exponent != sp(1.0)) {
-          nccn_scaled = pow(nccn_scaled, spa_ccn_to_nc_exponent);
-        }
+        // Second, apply the exponent
+        nccn_scaled = pow(nccn_scaled, spa_ccn_to_nc_exponent);
         // Third, apply the factor, and retain the max
         nc(k).set(not_drymass,
                   max(nc(k), spa_ccn_to_nc_factor * nccn_scaled));