diff --git a/physics/CONV/SAMF/samfshalcnv.f b/physics/CONV/SAMF/samfshalcnv.f
index 3869ea6ea..d0bab05dd 100644
--- a/physics/CONV/SAMF/samfshalcnv.f
+++ b/physics/CONV/SAMF/samfshalcnv.f
@@ -191,7 +191,7 @@ subroutine samfshalcnv_run(im,km,itc,ntc,cliq,cp,cvap,            &
       parameter(cinacrmx=-120.,shevf=2.0)
       parameter(dtmax=10800.,dtmin=600.)
       parameter(bb1=4.0,bb2=0.8,csmf=0.2)
-      parameter(tkcrt=2.,cmxfac=15.)
+      parameter(tkcrt=2.,cmxfac=10.)
 !      parameter(bet1=1.875,cd1=.506,f1=2.0,gam1=.5)
       parameter(betaw=.03,dxcrtc0=9.e3)
       parameter(h1=0.33333333)
diff --git a/physics/PBL/SATMEDMF/satmedmfvdifq.F b/physics/PBL/SATMEDMF/satmedmfvdifq.F
index 73fc4aff8..7b54b6d12 100644
--- a/physics/PBL/SATMEDMF/satmedmfvdifq.F
+++ b/physics/PBL/SATMEDMF/satmedmfvdifq.F
@@ -271,7 +271,7 @@ subroutine satmedmfvdifq_run(im,km,ntrac,ntcw,ntrw,               &
       parameter(elmfac=1.0,elefac=1.0,cql=100.)
       parameter(dw2min=1.e-4,dkmax=1000.,xkgdx=1000.)
       parameter(qlcr=3.5e-5,zstblmax=2500.)
-      parameter(xkinv1=0.15,xkinv2=0.3)
+      parameter(xkinv1=0.4,xkinv2=0.3)
       parameter(h1=0.33333333,hcrinv=250.)
       parameter(vegflo=0.1,vegfup=1.0,z0lo=0.1,z0up=1.0)
       parameter(vc0=1.0,zc0=1.0)
diff --git a/physics/SFC_Layer/UFS/sfc_diff.f b/physics/SFC_Layer/UFS/sfc_diff.f
index c5ed8bfa6..5dd6525f9 100644
--- a/physics/SFC_Layer/UFS/sfc_diff.f
+++ b/physics/SFC_Layer/UFS/sfc_diff.f
@@ -350,12 +350,24 @@ subroutine sfc_diff_run (im,rvrdm1,eps,epsm1,grav,                &  !intent(in)
               tvs        = half * (tsurf_wat(i)+tskin_wat(i))/prsik1(i)
      &                          * virtfac
             endif
-
-            z0           = 0.01_kp * z0rl_wat(i)
-            z0max        = max(zmin, min(z0,z1(i)))
-!           ustar_wat(i) = sqrt(grav * z0 / charnock)
+!
             wind10m      = sqrt(u10m(i)*u10m(i)+v10m(i)*v10m(i))
+!
+            if (sfc_z0_type == -1) then    ! using wave model derived momentum roughness
+              tem1 = 0.11 * vis / ustar_wat(i)
+              z0 = tem1 +  0.01_kp * z0rl_wav(i)
 
+              if (redrag) then
+                z0max = max(min(z0, z0s_max),1.0e-7_kp)
+              else
+                z0max = max(min(z0,0.1_kp), 1.0e-7_kp)
+              endif
+              z0rl_wat(i) = 100.0_kp * z0max   ! cm
+            else
+              z0    = 0.01_kp * z0rl_wat(i)
+              z0max = max(zmin, min(z0,z1(i)))
+            endif
+!
 !**  test xubin's new z0
 
 !           ztmax  = z0max
@@ -425,17 +437,18 @@ subroutine sfc_diff_run (im,rvrdm1,eps,epsm1,grav,                &  !intent(in)
                  z0rl_wat(i) = 1.0e-4_kp
               endif
 
-            elseif (z0rl_wav(i) <= 1.0e-7_kp .or.                       &
-     &              z0rl_wav(i) > 1.0_kp) then
-!             z0 = (charnock / grav) * ustar_wat(i) * ustar_wat(i)
-              tem1 = 0.11 * vis / ustar_wat(i)
-              z0 = tem1 + (charnock/grav)*ustar_wat(i)*ustar_wat(i)
+           elseif (z0rl_wav(i) <= 1.0e-7_kp .or.
+     &             z0rl_wav(i) > 1.0_kp) then
+!            z0 = (charnock / grav) * ustar_wat(i) * ustar_wat(i)
+             tem1 = 0.11 * vis / ustar_wat(i)
+             z0 = tem1 + (charnock/grav)*ustar_wat(i)*ustar_wat(i)
+
+             if (redrag) then
+               z0rl_wat(i) = 100.0_kp * max(min(z0, z0s_max),1.0e-7_kp)
+             else
+               z0rl_wat(i) = 100.0_kp * max(min(z0,0.1_kp), 1.0e-7_kp)
+             endif
 
-              if (redrag) then
-                z0rl_wat(i) = 100.0_kp * max(min(z0, z0s_max),1.0e-7_kp)
-              else
-                z0rl_wat(i) = 100.0_kp * max(min(z0,0.1_kp), 1.0e-7_kp)
-              endif
             endif
 
           endif              ! end of if(open ocean)
diff --git a/tools/check_encoding.py b/tools/check_encoding.py
index 1d24d4679..d964ebaab 100755
--- a/tools/check_encoding.py
+++ b/tools/check_encoding.py
@@ -15,11 +15,7 @@
         if suffix in SUFFICES:
             with open(os.path.join(root, file)) as f:
                 contents = f.read()
-            try:
-                contents.decode('ascii')
-            except UnicodeDecodeError:
+            if not contents.isascii():
                 for line in contents.split('\n'):
-                    try:
-                        line.decode('ascii')
-                    except UnicodeDecodeError:
+                    if not line.isascii():
                         raise Exception('Detected non-ascii characters in file {}, line: "{}"'.format(os.path.join(root, file), line))