added nl parameter for radius of newly formed rain drops from autocon…

…version
E3SM-Project · Oct 4, 2024 · 7895945 · 7895945
1 parent e3b223c
commit 7895945
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Showing 3 changed files with 13 additions and 2 deletions.
diff --git a/components/eamxx/cime_config/namelist_defaults_scream.xml b/components/eamxx/cime_config/namelist_defaults_scream.xml
@@ -205,6 +205,7 @@ be lost if SCREAM_HACK_XML is not enabled.
       <p3_autoconversion_prefactor type="real" doc="P3 autoconversion_prefactor (scale factor in autoconversion)">1350.0</p3_autoconversion_prefactor>
       <p3_autoconversion_qc_exp type="real" doc="P3 autoconversion qc exponent">2.47</p3_autoconversion_qc_exp>
       <p3_autoconversion_nc_exp type="real" doc="P3 autoconversion nc exponent">1.79</p3_autoconversion_nc_exp>
+      <p3_autoconversion_radius type="real" doc="P3 autoconversion radius of new rain drops">0.000025</p3_autoconversion_radius>
       <p3_accretion_qc_exp type="real" doc="P3 accretion qc exponent">1.15</p3_accretion_qc_exp>
       <p3_accretion_qr_exp type="real" doc="P3 accretion qr exponent">1.15</p3_accretion_qr_exp>
       <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>

diff --git a/components/eamxx/src/physics/p3/impl/p3_autoconversion_impl.hpp b/components/eamxx/src/physics/p3/impl/p3_autoconversion_impl.hpp
@@ -20,11 +20,13 @@ ::cloud_water_autoconversion(
 
   // Khroutdinov and Kogan (2000)
   const auto qc_not_small = qc_incld >= 1e-8 && context;
-  constexpr Scalar CONS3 = C::CONS3;
+//  constexpr Scalar CONS3 = C::CONS3;
+  constexpr Scalar CONS2 = C::CONS2;
 
   const Scalar p3_autoconversion_prefactor = p3constants.p3_autoconversion_prefactor;
   const Scalar p3_autoconversion_qc_exp = p3constants.p3_autoconversion_qc_exp;
   const Scalar p3_autoconversion_nc_exp = p3constants.p3_autoconversion_nc_exp;
+  const Scalar p3_autoconversion_radius = p3constants.p3_autoconversion_radius;
 
 
 //printf("  hey inside  AAAAAAAAAAAAAAAA %13.6f \n", p3_autoconversion_factor);
@@ -37,7 +39,7 @@ ::cloud_water_autoconversion(
     qc2qr_autoconv_tend.set(qc_not_small,
               sgs_var_coef*p3_autoconversion_prefactor*pow(qc_incld,sp(p3_autoconversion_qc_exp))*pow(nc_incld*sp(1.e-6)*rho,sp(-p3_autoconversion_nc_exp)));
     // note: ncautr is change in Nr; nc2nr_autoconv_tend is change in Nc
-    ncautr.set(qc_not_small, qc2qr_autoconv_tend*CONS3);
+    ncautr.set(qc_not_small, qc2qr_autoconv_tend/(CONS2*pow(p3_autoconversion_radius,3.0)));
     nc2nr_autoconv_tend.set(qc_not_small, qc2qr_autoconv_tend*nc_incld/qc_incld);
   }
 

diff --git a/components/eamxx/src/physics/share/physics_constants.hpp b/components/eamxx/src/physics/share/physics_constants.hpp
@@ -129,6 +129,7 @@ struct P3_Constants
   Scalar p3_autoconversion_prefactor = 1350.0;
   Scalar p3_autoconversion_qc_exp = 2.47;
   Scalar p3_autoconversion_nc_exp = 1.79;
+  Scalar p3_autoconversion_radius = 0.000025;
   Scalar p3_accretion_qc_exp = 1.15;
   Scalar p3_accretion_qr_exp = 1.15;
   Scalar p3_mu_r_constant             = 1.0;
@@ -158,6 +159,10 @@ struct P3_Constants
     if(params.isParameter(nname))
        p3_autoconversion_nc_exp = params.get<double>(nname);
 
+    nname = "p3_autoconversion_radius";
+    if(params.isParameter(nname))
+       p3_autoconversion_radius = params.get<double>(nname);
+
     nname = "p3_accretion_qc_exp";
     if(params.isParameter(nname))
        p3_accretion_qc_exp = params.get<double>(nname);
@@ -228,6 +233,9 @@ struct P3_Constants
       nname = "p3_autoconversion_nc_exp";
       logger->info(std::string("P3   ") + nname + std::string(" = ") + std::to_string(p3_autoconversion_nc_exp));
 
+      nname = "p3_autoconversion_radius";
+      logger->info(std::string("P3   ") + nname + std::string(" = ") + std::to_string(p3_autoconversion_radius));
+
       nname = "p3_accretion_qc_exp";
       logger->info(std::string("P3   ") + nname + std::string(" = ") + std::to_string(p3_autoconversion_qc_exp));