Changeset 18484

Timestamp:

09/08/14 01:03:45 (11 years ago)

Author:

jbondzio

Message:

CHG: Use absolute values for artificial diffusion, as negative entries in diffusion matrix might lead to destabilizing contraction effect. Constrain watercolumn to nonnegative values only.

Location:

issm/trunk-jpl

Files:

• src/c/analyses/EnthalpyAnalysis.cpp (modified) (2 diffs)
• test/Archives/Archive120.nc (modified) ( previous)
• test/Archives/Archive121.nc (modified) ( previous)
• test/Archives/Archive122.nc (modified) ( previous)
• test/Archives/Archive325.nc (modified) ( previous)
• test/Archives/Archive326.nc (modified) ( previous)
• test/Archives/Archive327.nc (modified) ( previous)
• test/Archives/Archive431.nc (modified) ( previous)
• test/Archives/Archive432.nc (modified) ( previous)
• test/Archives/Archive803.nc (modified) ( previous)
• test/Archives/Archive805.nc (modified) ( previous)

issm/trunk-jpl/src/c/analyses/EnthalpyAnalysis.cpp

@@ -315 +315 @@
                         vel=sqrt(vx*vx + vy*vy + vz*vz)+1.e-14;
                         h=sqrt( pow(hx*vx/vel,2) + pow(hy*vy/vel,2) + pow(hz*vz/vel,2));
-                        K[0][0]=h/(2.*vel)*vx*vx;  K[0][1]=h/(2.*vel)*vx*vy; K[0][2]=h/(2.*vel)*vx*vz;
-                        K[1][0]=h/(2.*vel)*vy*vx;  K[1][1]=h/(2.*vel)*vy*vy; K[1][2]=h/(2.*vel)*vy*vz;
-                        K[2][0]=h/(2.*vel)*vz*vx;  K[2][1]=h/(2.*vel)*vz*vy; K[2][2]=h/(2.*vel)*vz*vz;
+                        K[0][0]=h/(2.*vel)*fabs(vx*vx);  K[0][1]=h/(2.*vel)*fabs(vx*vy); K[0][2]=h/(2.*vel)*fabs(vx*vz);
+                        K[1][0]=h/(2.*vel)*fabs(vy*vx);  K[1][1]=h/(2.*vel)*fabs(vy*vy); K[1][2]=h/(2.*vel)*fabs(vy*vz);
+                        K[2][0]=h/(2.*vel)*fabs(vz*vx);  K[2][1]=h/(2.*vel)*fabs(vz*vy); K[2][2]=h/(2.*vel)*fabs(vz*vz);
                         for(int i=0;i<3;i++) for(int j=0;j<3;j++) K[i][j] = D_scalar*K[i][j];
 
@@ -1028 +1028 @@
                 else{
                         basalmeltingrate[vertexdown]=meltingrate_enthalpy[is];
-                        watercolumn[vertexdown]+=meltingrate_enthalpy[is];
+                        if(watercolumn[vertexdown]+meltingrate_enthalpy[is]<0.)
+                                watercolumn[vertexdown]=0.;
+                        else
+                                watercolumn[vertexdown]+=meltingrate_enthalpy[is];
                 }       
                 basalmeltingrate[vertexdown]*=rho_water/rho_ice; // convert meltingrate from water to ice equivalent