accr/auto runtime

components/eamxx/cime_config/namelist_defaults_scream.xml

@@ -202,10 +202,14 @@ be lost if SCREAM_HACK_XML is not enabled.
         ${DIN_LOC_ROOT}/atm/scream/tables/vn_table_vals.dat8,
         ${DIN_LOC_ROOT}/atm/scream/tables/vm_table_vals.dat8
       </tables>
-      <p3_autoconversion_prefactor type="real" doc="P3 autoconversion_prefactor (scale factor in autoconversion)">1350.0</p3_autoconversion_prefactor>
+      <p3_autoconversion_prefactor type="real" doc="Autoconversion linear prefactor in P3">1350.0</p3_autoconversion_prefactor>
+      <p3_autoconversion_qc_exponent type="real" doc="Autoconversion qc exponent in P3">2.47</p3_autoconversion_qc_exponent>
+      <p3_autoconversion_nc_exponent type="real" doc="Autoconversion nc exponent in P3">1.79</p3_autoconversion_nc_exponent>
+      <p3_accretion_prefactor type="real" doc="Accretion linear prefactor in P3">67.0</p3_accretion_prefactor>
+      <p3_accretion_qc_exponent type="real" doc="Accretion qc exponent in P3">1.15</p3_accretion_qc_exponent>
+      <p3_accretion_qr_exponent type="real" doc="Accretion qr exponent in P3">1.15</p3_accretion_qr_exponent>
       <p3_mu_r_constant type="real" doc="P3 mu_r_constant (rain shape parameter in gamma drop-size distribution)">1.0</p3_mu_r_constant>
       <p3_spa_to_nc type="real" doc="P3 spa_to_nc (scaling factor for turning CCN into nc in SPA)">1.0</p3_spa_to_nc>
-      <p3_k_accretion type="real" doc="P3 k_accretion (scaling factor on accretion)">67.0</p3_k_accretion>
       <p3_eci type="real" doc="P3 eci (liquid/ice collision/collection coefficient)">0.5</p3_eci>
       <p3_eri type="real" doc="P3 eri (ice/rain collision/collection coefficient)">1.0</p3_eri>
       <p3_rho_rime_min type="real" doc="P3 rho_rime_min (riming density maximum)">50.0</p3_rho_rime_min>

components/eamxx/src/physics/p3/eamxx_p3_process_interface.cpp

@@ -222,9 +222,13 @@ void P3Microphysics::initialize_impl (const RunType /* run_type */)
   // Gather runtime options
   runtime_options.max_total_ni = m_params.get<double>("max_total_ni", 740.0e3);
   runtime_options.p3_autoconversion_prefactor = m_params.get<double>("p3_autoconversion_prefactor", 1350.0);
+  runtime_options.p3_autoconversion_qc_exponent = m_params.get<double>("p3_autoconversion_qc_exponent", 2.47);
+  runtime_options.p3_autoconversion_nc_exponent = m_params.get<double>("p3_autoconversion_nc_exponent", 1.79);
+  runtime_options.p3_accretion_prefactor = m_params.get<double>("p3_accretion_prefactor", 67.0);
+  runtime_options.p3_accretion_qc_exponent = m_params.get<double>("p3_accretion_qc_exponent", 1.15);
+  runtime_options.p3_accretion_qr_exponent = m_params.get<double>("p3_accretion_qr_exponent", 1.15);
   runtime_options.p3_mu_r_constant = m_params.get<double>("p3_mu_r_constant", 1.0);
   runtime_options.p3_spa_to_nc = m_params.get<double>("p3_spa_to_nc", 1.0);
-  runtime_options.p3_k_accretion = m_params.get<double>("p3_k_accretion", 67.0);
   runtime_options.p3_eci = m_params.get<double>("p3_eci", 0.5);
   runtime_options.p3_eri = m_params.get<double>("p3_eri", 1.0);
   runtime_options.p3_rho_rime_min = m_params.get<double>("p3_rho_rime_min", 50.0);

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

@@ -22,17 +22,23 @@ ::cloud_water_autoconversion(
   constexpr Scalar CONS3 = C::CONS3;
 
   const Scalar p3_autoconversion_prefactor = runtime_options.p3_autoconversion_prefactor;
+  const Scalar p3_autoconversion_qc_exponent = runtime_options.p3_autoconversion_qc_exponent;
+  const Scalar p3_autoconversion_nc_exponent = runtime_options.p3_autoconversion_nc_exponent;
 
-  if(qc_not_small.any()){
+  if(qc_not_small.any()) {
     Spack sgs_var_coef;
     // sgs_var_coef = subgrid_variance_scaling(inv_qc_relvar, sp(2.47) );
     sgs_var_coef = 1;
 
-    qc2qr_autoconv_tend.set(qc_not_small,
-              sgs_var_coef*p3_autoconversion_prefactor*pow(qc_incld,sp(2.47))*pow(nc_incld*sp(1.e-6)*rho,sp(-1.79)));
+    qc2qr_autoconv_tend.set(
+        qc_not_small, sgs_var_coef * p3_autoconversion_prefactor *
+                          pow(qc_incld, sp(p3_autoconversion_qc_exponent)) *
+                          pow(nc_incld * sp(1.e-6) * rho,
+                              sp(-1 * p3_autoconversion_nc_exponent)));
     // note: ncautr is change in Nr; nc2nr_autoconv_tend is change in Nc
-    ncautr.set(qc_not_small, qc2qr_autoconv_tend*CONS3);
-    nc2nr_autoconv_tend.set(qc_not_small, qc2qr_autoconv_tend*nc_incld/qc_incld);
+    ncautr.set(qc_not_small, qc2qr_autoconv_tend * CONS3);
+    nc2nr_autoconv_tend.set(qc_not_small,
+                            qc2qr_autoconv_tend * nc_incld / qc_incld);
   }
 
   nc2nr_autoconv_tend.set(qc2qr_autoconv_tend == 0 && context, 0);

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

@@ -25,18 +25,23 @@ ::cloud_rain_accretion(
 {
   constexpr Scalar qsmall = C::QSMALL;
 
-  const Scalar p3_k_accretion = runtime_options.p3_k_accretion;;
+  const Scalar p3_accretion_prefactor = runtime_options.p3_accretion_prefactor;
+  const Scalar p3_accretion_qc_exponent = runtime_options.p3_accretion_qc_exponent;
+  const Scalar p3_accretion_qr_exponent = runtime_options.p3_accretion_qr_exponent;
 
   Spack sgs_var_coef;
   // sgs_var_coef = subgrid_variance_scaling(inv_qc_relvar, sp(1.15) );
   sgs_var_coef = 1;
 
   const auto qr_and_qc_not_small = (qr_incld >= qsmall) && (qc_incld >= qsmall) && context;
-  if (qr_and_qc_not_small.any()) {
+  if(qr_and_qc_not_small.any()) {
     // Khroutdinov and Kogan (2000)
     qc2qr_accret_tend.set(qr_and_qc_not_small,
-              sgs_var_coef * sp(p3_k_accretion) * pow(qc_incld * qr_incld, sp(1.15)));
-    nc_accret_tend.set(qr_and_qc_not_small, qc2qr_accret_tend * nc_incld / qc_incld);
+                          sgs_var_coef * sp(p3_accretion_prefactor) *
+                              pow(qc_incld, sp(p3_accretion_qc_exponent)) *
+                              pow(qr_incld, sp(p3_accretion_qr_exponent)));
+    nc_accret_tend.set(qr_and_qc_not_small,
+                       qc2qr_accret_tend * nc_incld / qc_incld);
 
     qc2qr_accret_tend.set(nc_accret_tend == 0 && context, 0);
     nc_accret_tend.set(qc2qr_accret_tend == 0 && context, 0);

components/eamxx/src/physics/p3/p3_functions.hpp

@@ -111,9 +111,13 @@ struct Functions
   struct P3Runtime {
     Scalar max_total_ni = 740.0e3;
     Scalar p3_autoconversion_prefactor = 1350.0;
+    Scalar p3_autoconversion_qc_exponent = 2.47;
+    Scalar p3_autoconversion_nc_exponent = 1.79;
+    Scalar p3_accretion_prefactor = 67.0;
+    Scalar p3_accretion_qc_exponent = 1.15;
+    Scalar p3_accretion_qr_exponent = 1.15;
     Scalar p3_mu_r_constant = 1.0;
     Scalar p3_spa_to_nc = 1.0;
-    Scalar p3_k_accretion = 67.0;
     Scalar p3_eci = 0.5;
     Scalar p3_eri = 1.0;
     Scalar p3_rho_rime_min = 50.0;