Index: /issm/trunk-jpl/src/m/classes/matice.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/matice.m	(revision 19013)
+++ /issm/trunk-jpl/src/m/classes/matice.m	(revision 19014)
@@ -143,5 +143,5 @@
 			md = checkfield(md,'fieldname','materials.rho_freshwater','>',0);
 			md = checkfield(md,'fieldname','materials.mu_water','>',0);
-			md = checkfield(md,'fieldname','materials.rheology_B','>',0,'size',[md.mesh.numberofvertices 1]);
+			md = checkfield(md,'fieldname','materials.rheology_B','>',0,'forcing',1,'NaN',1);
 			md = checkfield(md,'fieldname','materials.rheology_n','>',0,'size',[md.mesh.numberofelements 1]);
 			md = checkfield(md,'fieldname','materials.rheology_law','values',{'None' 'Cuffey' 'Paterson' 'Arrhenius' 'LliboutryDuval'});
@@ -192,5 +192,5 @@
 			WriteData(fid,'object',obj,'class','materials','fieldname','mixed_layer_capacity','format','Double');
 			WriteData(fid,'object',obj,'class','materials','fieldname','thermal_exchange_velocity','format','Double');
-			WriteData(fid,'object',obj,'class','materials','fieldname','rheology_B','format','DoubleMat','mattype',1);
+			WriteData(fid,'object',obj,'class','materials','fieldname','rheology_B','format','DoubleMat','mattype',1,'forcinglength',md.mesh.numberofvertices+1);
 			WriteData(fid,'object',obj,'class','materials','fieldname','rheology_n','format','DoubleMat','mattype',2);
 			WriteData(fid,'data',StringToEnum(obj.rheology_law),'enum',MaterialsRheologyLawEnum(),'format','Integer');
Index: /issm/trunk-jpl/src/m/classes/matice.py
===================================================================
--- /issm/trunk-jpl/src/m/classes/matice.py	(revision 19013)
+++ /issm/trunk-jpl/src/m/classes/matice.py	(revision 19014)
@@ -117,5 +117,5 @@
 		md = checkfield(md,'fieldname','materials.rho_freshwater','>',0)
 		md = checkfield(md,'fieldname','materials.mu_water','>',0)
-		md = checkfield(md,'fieldname','materials.rheology_B','>',0,'size',[md.mesh.numberofvertices])
+		md = checkfield(md,'fieldname','materials.rheology_B','>',0,'forcing',1,'NaN',1)
 		md = checkfield(md,'fieldname','materials.rheology_n','>',0,'size',[md.mesh.numberofelements])
 		md = checkfield(md,'fieldname','materials.rheology_law','values',['None','Cuffey','Paterson','Arrhenius','LliboutryDuval'])
@@ -140,4 +140,5 @@
 		WriteData(fid,'object',self,'class','materials','fieldname','mixed_layer_capacity','format','Double')
 		WriteData(fid,'object',self,'class','materials','fieldname','thermal_exchange_velocity','format','Double')
+		WriteData(fid,'object',self,'class','materials','fieldname','rheology_B','format','DoubleMat','mattype',1,'forcinglength',md.mesh.numberofvertices+1)
 		WriteData(fid,'object',self,'class','materials','fieldname','rheology_B','format','DoubleMat','mattype',1)
 		WriteData(fid,'object',self,'class','materials','fieldname','rheology_n','format','DoubleMat','mattype',2)