avoid division by zero in case of zero oxygen (#496)

NorESMhub · Feb 14, 2025 · c8d519a · c8d519a
1 parent 81cc72f
commit c8d519a
Show file tree

Hide file tree

Showing 2 changed files with 4 additions and 4 deletions.
diff --git a/hamocc/mo_extNsediment.F90 b/hamocc/mo_extNsediment.F90
@@ -171,7 +171,7 @@ subroutine sed_nitrification(j,kpie,kpje,kpke,kbnd,ptho,omask,ex_ddic,ex_dalk)
           fdetamox = 1. - (fn2o + fno2)
 
           ! NO2 oxidizing step of nitrification
-          Tdepano2    = q10ano2nitr_sed**((temp-Trefano2nitr_sed)/10.) 
+          Tdepano2    = q10ano2nitr_sed**((temp-Trefano2nitr_sed)/10.)
           O2limano2   = powtra(i,j,k,ipowaox)/(powtra(i,j,k,ipowaox) + bkoxnitr_sed)
           nut2lim     = powtra(i,j,k,ipowno2)/(powtra(i,j,k,ipowno2) + bkano2nitr_sed)
           ano2new     = powtra(i,j,k,ipowno2)/(1. + rano2nitr_sed*Tdepano2*O2limano2*nut2lim)
@@ -186,7 +186,7 @@ subroutine sed_nitrification(j,kpie,kpje,kpke,kbnd,ptho,omask,ex_ddic,ex_dalk)
           no2fdetamox = NOB2AOAy_sed*n2omaxy_sed*2.*(1. + n2oybeta_sed)*powtra(i,j,k,ipowaox)*bkyamox_sed  &
                       & /(powtra(i,j,k,ipowaox)**2 + 2.*powtra(i,j,k,ipowaox)*bkyamox_sed + bkyamox_sed**2)
 
-          fdetnitr = no2fdetamox/(no2fno2 + no2fn2o)   ! yield to energy usage ratio for NO2 -> ratio equals 16:x
+          fdetnitr = no2fdetamox/(no2fno2 + no2fn2o + eps)   ! yield to energy usage ratio for NO2 -> ratio equals 16:x
 
           ! limitation of the two processes through available nutrients, etc.
           totd     = potdnh4amox + potdno2nitr

diff --git a/hamocc/mo_extNwatercol.F90 b/hamocc/mo_extNwatercol.F90
@@ -152,7 +152,7 @@ subroutine nitrification(kpie,kpje,kpke,kbnd,pddpo,omask,ptho)
             no2fdetamox = NOB2AOAy*n2omaxy*2.*(1. + n2oybeta)*ocetra(i,j,k,ioxygen)*bkyamox        &
                         & /(ocetra(i,j,k,ioxygen)**2 + 2.*ocetra(i,j,k,ioxygen)*bkyamox + bkyamox**2)
 
-            fdetnitr = no2fdetamox/(no2fno2 + no2fn2o)   ! yield to energy usage ratio for NO2 -> ratio equals 16:x
+            fdetnitr = no2fdetamox/(no2fno2 + no2fn2o + eps)   ! yield to energy usage ratio for NO2 -> ratio equals 16:x
 
 
           ! limitation of the two processes through available nutrients, etc.
@@ -217,7 +217,7 @@ subroutine denit_NO3_to_NO2(kpie,kpje,kpke,kbnd,pddpo,omask,ptho)
     integer :: i,j,k
     real    :: Tdep,O2inhib,nutlim,ano3new,ano3denit,temp
 
-    ! Sett output-related field to zero
+    ! Set output-related field to zero
     denit_NO3  = 0.
 
     !$OMP PARALLEL DO PRIVATE(i,k,Tdep,O2inhib,nutlim,ano3new,ano3denit,temp)