diff --git a/src/chemistry/aerosol/carma_aerosol_properties_mod.F90 b/src/chemistry/aerosol/carma_aerosol_properties_mod.F90
index ebf50759bc..57d513d48b 100644
--- a/src/chemistry/aerosol/carma_aerosol_properties_mod.F90
+++ b/src/chemistry/aerosol/carma_aerosol_properties_mod.F90
@@ -716,7 +716,7 @@ function scav_diam(self, bin_ndx) result(diam)
     end do
 
     ! specdens kg/m3 to g/cm3, convert from radius to diameter
-    diam = 2._r8*((0.75*mass / pi  / (1.0e-3_r8*rho))**onethird)
+    diam = 2._r8*((0.75_r8*mass / pi  / (1.0e-3_r8*rho))**onethird)
 
   end function scav_diam
 
diff --git a/src/chemistry/carma_aero/carma_aero_gasaerexch.F90 b/src/chemistry/carma_aero/carma_aero_gasaerexch.F90
index e78b9f9406..ed8cf30859 100644
--- a/src/chemistry/carma_aero/carma_aero_gasaerexch.F90
+++ b/src/chemistry/carma_aero/carma_aero_gasaerexch.F90
@@ -777,7 +777,7 @@ subroutine gas_aer_uptkrates( ncol,       loffset,                &
               gasspeed  = 1.470e1_r8 * sqrt(t(i,k))
 !   freepathx2 = 2 * (h2so4 mean free path)  (m)
               freepathx2 = 6.0_r8*gasdiffus/gasspeed
-              dp = wetr(i,k,n) * 1.e-2 ! meters
+              dp = wetr(i,k,n) * 1.e-2_r8 ! meters
               const = tworootpi * num_bin(i,k,n) * 2.0_r8 * dp
               ! gas_conden_rate(Dp) = const *  gasdiffus *  F(Kn,ac)
               !   knudsen number
diff --git a/src/physics/carma/cam/carma_intr.F90 b/src/physics/carma/cam/carma_intr.F90
index 47af8ff6fc..72ca0b5f87 100644
--- a/src/physics/carma/cam/carma_intr.F90
+++ b/src/physics/carma/cam/carma_intr.F90
@@ -3951,8 +3951,8 @@ subroutine carma_get_wet_radius(state, igroup, ibin, rwet, rhopwet, rc)
     end do
 
     ! Convert rwet and rhopwet to mks units
-    rwet(:ncol,:) = rwet(:ncol,:) * 1.e-2 ! cm --> m
-    rhopwet(:ncol,:) = rhopwet(:ncol,:) * 1.e3 ! g/cm3 --> kg/m3
+    rwet(:ncol,:) = rwet(:ncol,:) * 1.e-2_r8 ! cm --> m
+    rhopwet(:ncol,:) = rhopwet(:ncol,:) * 1.e3_r8 ! g/cm3 --> kg/m3
 
     if (rc/=RC_OK) then
        call endrun('carma_get_wet_radius ERROR8: rc = ',rc)
diff --git a/src/physics/carma/models/trop_strat_soa1/carma_model_mod.F90 b/src/physics/carma/models/trop_strat_soa1/carma_model_mod.F90
index ad8967f688..50d9981ff4 100644
--- a/src/physics/carma/models/trop_strat_soa1/carma_model_mod.F90
+++ b/src/physics/carma/models/trop_strat_soa1/carma_model_mod.F90
@@ -235,7 +235,7 @@ module carma_model_mod
       3.74323598e-08_f, 1.63841034e-09_f, 2.49434956e-09_f, 1.52413800e-08_f, &
       3.35000010e-08_f, 3.43825518e-02_f /)
 
-
+  real(r8), parameter :: onethird = 1._r8/3._r8
 
 contains
 
@@ -1657,11 +1657,11 @@ subroutine CARMAMODEL_CreateOpticsFile_MixedYu(carma, igroup, rc)
             do iwave = 1, NWAVE
 
               ! For now just assume BC/OC constant 15%
-              ! rcore = r(ibin)*(0.15**(1./3))
+              ! rcore = r(ibin)*(0.15**onethird)
               ! Using Mie code, consider core/shell ratio
               do icsr = 1, ncsr
                 if (ncsr > 1) then
-                  rcore = r(ibin)*(coreshellratio(icsr)**(1./3))
+                  rcore = r(ibin)*(coreshellratio(icsr)**onethird)
                 else
                   rcore = 0.0_f
                 endif
@@ -2109,11 +2109,11 @@ subroutine CARMAMODEL_CreateOpticsFile_MixedYuH2o(carma, igroup, rc)
             do iwave = 1, NWAVE
 
               ! For now just assume BC/OC constant 15%
-              ! rcore = r(ibin)*(0.15**(1./3))
+              ! rcore = r(ibin)*(0.15**onethird)
               ! Using Mie code, consider core/shell ratio
               do icsr = 1, ncsr
                 if (ncsr > 1) then
-                  rcore = r(ibin)*(coreshellratio(icsr)**(1./3))
+                  rcore = r(ibin)*(coreshellratio(icsr)**onethird)
                 else
                   rcore = 0.0_f
                 endif
diff --git a/src/physics/carma/models/trop_strat_soa5/carma_model_mod.F90 b/src/physics/carma/models/trop_strat_soa5/carma_model_mod.F90
index ec657f70a5..7bbd8f9907 100644
--- a/src/physics/carma/models/trop_strat_soa5/carma_model_mod.F90
+++ b/src/physics/carma/models/trop_strat_soa5/carma_model_mod.F90
@@ -255,7 +255,7 @@ module carma_model_mod
       3.74323598e-08_f, 1.63841034e-09_f, 2.49434956e-09_f, 1.52413800e-08_f, &
       3.35000010e-08_f, 3.43825518e-02_f /)
 
-
+  real(r8), parameter :: onethird = 1._r8/3._r8
 
 contains
 
@@ -1859,11 +1859,11 @@ subroutine CARMAMODEL_CreateOpticsFile_MixedYu(carma, igroup, rc)
             do iwave = 1, NWAVE
 
               ! For now just assume BC/OC constant 15%
-              ! rcore = r(ibin)*(0.15**(1./3))
+              ! rcore = r(ibin)*(0.15**onethird)
               ! Using Mie code, consider core/shell ratio
               do icsr = 1, ncsr
                 if (ncsr > 1) then
-                  rcore = r(ibin)*(coreshellratio(icsr)**(1./3))
+                  rcore = r(ibin)*(coreshellratio(icsr)**onethird)
                 else
                   rcore = 0.0_f
                 endif
@@ -2311,11 +2311,11 @@ subroutine CARMAMODEL_CreateOpticsFile_MixedYuH2o(carma, igroup, rc)
             do iwave = 1, NWAVE
 
               ! For now just assume BC/OC constant 15%
-              ! rcore = r(ibin)*(0.15**(1./3))
+              ! rcore = r(ibin)*(0.15**onethird)
               ! Using Mie code, consider core/shell ratio
               do icsr = 1, ncsr
                 if (ncsr > 1) then
-                  rcore = r(ibin)*(coreshellratio(icsr)**(1./3))
+                  rcore = r(ibin)*(coreshellratio(icsr)**onethird)
                 else
                   rcore = 0.0_f
                 endif