add selfcollection prefactor

E3SM-Project · Oct 11, 2024 · 7c859f0 · 7c859f0
1 parent 90c7b94
commit 7c859f0
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Showing 4 changed files with 7 additions and 1 deletion.
diff --git a/components/eamxx/cime_config/namelist_defaults_scream.xml b/components/eamxx/cime_config/namelist_defaults_scream.xml
@@ -208,6 +208,7 @@ be lost if SCREAM_HACK_XML is not enabled.
       <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_rain_selfcollection_prefactor type="real" doc="Rain selfcollection prefactor in P3">5.78</p3_rain_selfcollection_prefactor>
       <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_eci type="real" doc="P3 eci (liquid/ice collision/collection coefficient)">0.5</p3_eci>

diff --git a/components/eamxx/src/physics/p3/eamxx_p3_process_interface.cpp b/components/eamxx/src/physics/p3/eamxx_p3_process_interface.cpp
@@ -227,6 +227,7 @@ void P3Microphysics::initialize_impl (const RunType /* run_type */)
   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_rain_selfcollection_prefactor = m_params.get<double>("p3_rain_selfcollection_prefactor", 5.78);
   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_eci = m_params.get<double>("p3_eci", 0.5);

diff --git a/components/eamxx/src/physics/p3/impl/p3_rain_self_collection_impl.hpp b/components/eamxx/src/physics/p3/impl/p3_rain_self_collection_impl.hpp
@@ -23,6 +23,7 @@ ::rain_self_collection(
   constexpr Scalar pi       = C::Pi;
 
   const Scalar p3_d_breakup_cutoff = runtime_options.p3_d_breakup_cutoff;
+  const Scalar p3_rain_selfcollection_prefactor = runtime_options.p3_rain_selfcollection_prefactor;
 
   const auto qr_incld_not_small = qr_incld >= qsmall && context;
 
@@ -38,7 +39,9 @@ ::rain_self_collection(
       dum.set(dum2_gt_dum1, 2 - exp(2300 * (dum2-p3_d_breakup_cutoff)));
     }
 
-    nr_selfcollect_tend.set(qr_incld_not_small, dum*sp(5.78)*nr_incld*qr_incld*rho);
+    nr_selfcollect_tend.set(
+        qr_incld_not_small,
+        dum * sp(p3_rain_selfcollection_prefactor) * nr_incld * qr_incld * rho);
   }
 }
 

diff --git a/components/eamxx/src/physics/p3/p3_functions.hpp b/components/eamxx/src/physics/p3/p3_functions.hpp
@@ -116,6 +116,7 @@ struct Functions
     Scalar p3_accretion_prefactor = 67.0;
     Scalar p3_accretion_qc_exponent = 1.15;
     Scalar p3_accretion_qr_exponent = 1.15;
+    Scalar p3_rain_selfcollection_prefactor = 5.78;
     Scalar p3_mu_r_constant = 1.0;
     Scalar p3_spa_to_nc = 1.0;
     Scalar p3_eci = 0.5;