Correction to grid_area for mid, lower, upper latitude

source/mod_tools.f90

@@ -179,9 +179,9 @@ module mod_tools
     real, parameter  :: pi=3.14159265, rearth=6.371e6, pih=pi/180.
     real             :: ylata, ylatp, ylatm, cosfact, cosfactp, cosfactm, hzone
 
-    ylata = ylat+(0.5)*dy
-    ylatp = ylata+0.5*dy
-    ylatm = ylat
+    ylata = ylat
+    ylatp = ylat+0.5*dy
+    ylatm = ylat-0.5*dy
     if (ylatm.lt.0.and.ylatp.gt.0) then
       hzone = rearth*pih
     else