modsamptend: fix closing of netCDF file

src/modsamptend.f90

@@ -1602,12 +1602,23 @@ end subroutine writenetcdf_proc
 !> Cleans up after the run
   subroutine exitsamptend
     use modstat_nc, only: exitstat_nc,lnetcdf
+    use modmpi, only: myid
   implicit none
 
     if (.not. lsamptend) return
     if(isamptot == 0) return
     if(.not.(lnetcdf)) return
-    call exitstat_nc(ncid)
+
+    if (lprocblock) then
+       ! Each block writes its own budget to its own file
+       call exitstat_nc(ncid)
+    else
+       ! We average over all blocks and write to a single file
+       if (myid==0) then
+          call exitstat_nc(ncid)
+       end if
+    end if
+
     if (lsamptendu) deallocate (uptm, upmn, upav, ust)
     if (lsamptendv) deallocate (vptm, vpmn, vpav, vst)
     if (lsamptendw) deallocate (wptm, wpmn, wpav, wst)