Changeset 25851

Timestamp:

12/10/20 16:38:21 (4 years ago)

Author:

schlegel

Message:

CHG: rework on GEMB grain growth

Location:

issm/trunk-jpl

Files:

• src/c/modules/SurfaceMassBalancex/Gembx.cpp (modified) (3 diffs)
• test/Archives/Archive243.arch (modified) ( previous)
• test/Archives/Archive244.arch (modified) ( previous)
• test/Archives/Archive252.arch (modified) ( previous)
• test/Archives/Archive253.arch (modified) ( previous)

issm/trunk-jpl/src/c/modules/SurfaceMassBalancex/Gembx.cpp

@@ -333 +333 @@
                         }
                         // dendricity and sphericity can not be > 1 or < 0
-         if (gdn[i]<0.0+Gdntol)gdn[i]=0.0;
-         if (gsp[i]<0.0+Gdntol)gsp[i]=0.0;
-         if (gdn[i]>1.0-Gdntol)gdn[i]=1.0;
-         if (gsp[i]>1.0-Gdntol)gsp[i]=1.0;
+         if (gdn[i]<=0.0+Gdntol)gdn[i]=0.0;
+         if (gsp[i]<=0.0+Gdntol)gsp[i]=0.0;
+         if (gdn[i]>=1.0-Gdntol)gdn[i]=1.0;
+         if (gsp[i]>=1.0-Gdntol)gsp[i]=1.0;
 
          // determine new grain size (mm)
@@ -344 +344 @@
                 else{
 
-                        //When the state of "faceted crystals" (gsp==0) is fully reached,
-                        // snow evolves towards depth hoar if the gradient is
-                        // higher than 15 degC m-1 (Brun et al., 1992)
                         //When wet-snow grains (class 6) are submitted to a
                         // temperature gradient higher than 5 degC m-1, their sphericity
@@ -352 +349 @@
                         // reaches 0, their size increases according to the functions
                         // determined by Marbouty. (Brun et al., 1992)
-                        if(gsp[i]>0.0+Gdntol && gsp[i]<1.0-Gdntol && (dT[i]>15.0+Ttol || (dT[i]>5.0+Ttol && W[i]>0.0+Wtol)) ){
-                                //determine coefficients
-                                IssmDouble C = (-2e8 * exp(-6e3 / T[i]) * dt) * pow(dT[i],.4);
-                                gsp[i] +=C;
-                                if (gsp[i]<0.0+Gdntol)gsp[i]=0.0;
-                                //determine new grain size (mm)
-                                gsz[i] = 0.35 + (0.5-gsp[i])*0.1;
-                        }
+                        if(gsp[i]>0.0+Gdntol && gsp[i]<1.0-Gdntol){
+
+                                IssmDouble F = 0.0;
+
+                                if (dT[i]>5.0+Ttol){
+                                        F = (-2e8 * exp(-6e3 / T[i]) * dt) * pow(dT[i],.4);
+                                }
+                                else if (W[i]>0.0+Wtol){
+                                        F = (1.0/16.0) * pow(lwc[i],3.0) * dt;
+                                }
+                                else{
+                                        F = 1e9 * exp(-6e3 / T[i]) * dt;
+                                }
+                                gsp[i] +=F;
+
+                        }
+                        if (gsp[i]<=0.0+Gdntol)gsp[i]=0.0;
+                        if (gsp[i]>=1.0-Gdntol)gsp[i]=1.0;
+
                         /*Dry snow metamorphism (Marbouty, 1980) grouped model coefficents
                          *from Marbouty, 1980: Figure 9*/
-                        else if(W[i]<=0.0+Wtol || (gsp[i]<=0.0+Gdntol && dT[i]>15.0+Ttol) || (gsp[i]<=0.0+Gdntol && dT[i]>5.0+Ttol && W[i]>0.0+Wtol)){
+                        if(W[i]<=0.0+Wtol || (gsp[i]<=0.0+Gdntol && dT[i]>5.0+Ttol)){
                                 //_printf_("Nondendritic snow metamorphism\n");
                                 Q = Marbouty(T[i],d[i],dT[i]);