diff --git a/src/chemistry/aerosol/bulk_aerosol_state_mod.F90 b/src/chemistry/aerosol/bulk_aerosol_state_mod.F90
index 4289adb086..53800cf033 100644
--- a/src/chemistry/aerosol/bulk_aerosol_state_mod.F90
+++ b/src/chemistry/aerosol/bulk_aerosol_state_mod.F90
@@ -2,7 +2,7 @@ module bulk_aerosol_state_mod
   use shr_kind_mod, only: r8 => shr_kind_r8
   use rad_constituents, only: rad_cnst_get_aer_mmr
   use cam_abortutils,   only: endrun
-  
+
   use physics_buffer, only: physics_buffer_desc
   use physics_types, only: physics_state
 
@@ -336,8 +336,13 @@ function dry_volume(self, aero_props, list_idx, bin_idx, ncol, nlev) result(vol)
     integer, intent(in) :: nlev      ! number of levels
 
     real(r8) :: vol(ncol,nlev)       ! m3/kg
+    real(r8), pointer :: mmr(:,:)    ! kg/kg
+    real(r8) :: dens                 ! kg/m3
+
+    call aero_props%get(bin_idx, 1, density=dens)
+    call self%get_ambient_mmr(list_idx, 1, bin_idx, mmr)
 
-    vol = -huge(1._r8)
+    vol(:ncol,:nlev) = mmr(:ncol,:nlev)/dens
 
   end function dry_volume
 
@@ -356,7 +361,8 @@ function wet_volume(self, aero_props, list_idx, bin_idx, ncol, nlev) result(vol)
 
     real(r8) :: vol(ncol,nlev)       ! m3/kg
 
-    vol = -huge(1._r8)
+    vol = self%dry_volume(aero_props, list_idx, bin_idx, ncol, nlev) &
+        + self%water_volume(aero_props, list_idx, bin_idx, ncol, nlev)
 
   end function wet_volume
 
@@ -375,7 +381,7 @@ function water_volume(self, aero_props, list_idx, bin_idx, ncol, nlev) result(vo
 
     real(r8) :: vol(ncol,nlev)       ! m3/kg
 
-    vol = -huge(1._r8)
+    vol = 0._r8
 
   end function water_volume
 
diff --git a/src/physics/cam/aerosol_optics_cam.F90 b/src/physics/cam/aerosol_optics_cam.F90
index eab1796814..de3f94e52a 100644
--- a/src/physics/cam/aerosol_optics_cam.F90
+++ b/src/physics/cam/aerosol_optics_cam.F90
@@ -1080,24 +1080,25 @@ subroutine update_diags( is_coarse_dust )
             sumhygro = hygrosulf(icol) + hygropom(icol) + hygrosoa(icol) + hygrobc(icol) + &
                  hygrodust(icol) + hygrosslt(icol)
 
-            scatdust(icol) = (scatdust(icol) + scath2o*hygrodust(icol)/sumhygro)/sumscat
-            absdust(icol)  = (absdust(icol) + absh2o*hygrodust(icol)/sumhygro)/sumabs
+            if (sumscat>0._r8 .and. sumabs>0._r8 .and. sumhygro>0._r8) then
+               scatdust(icol) = (scatdust(icol) + scath2o*hygrodust(icol)/sumhygro)/sumscat
+               absdust(icol)  = (absdust(icol) + absh2o*hygrodust(icol)/sumhygro)/sumabs
 
-            scatsulf(icol) = (scatsulf(icol) + scath2o*hygrosulf(icol)/sumhygro)/sumscat
-            abssulf(icol)  = (abssulf(icol) + absh2o*hygrosulf(icol)/sumhygro)/sumabs
+               scatsulf(icol) = (scatsulf(icol) + scath2o*hygrosulf(icol)/sumhygro)/sumscat
+               abssulf(icol)  = (abssulf(icol) + absh2o*hygrosulf(icol)/sumhygro)/sumabs
 
-            scatpom(icol) = (scatpom(icol) + scath2o*hygropom(icol)/sumhygro)/sumscat
-            abspom(icol)  = (abspom(icol) + absh2o*hygropom(icol)/sumhygro)/sumabs
+               scatpom(icol) = (scatpom(icol) + scath2o*hygropom(icol)/sumhygro)/sumscat
+               abspom(icol)  = (abspom(icol) + absh2o*hygropom(icol)/sumhygro)/sumabs
 
-            scatsoa(icol) = (scatsoa(icol) + scath2o*hygrosoa(icol)/sumhygro)/sumscat
-            abssoa(icol)  = (abssoa(icol) + absh2o*hygrosoa(icol)/sumhygro)/sumabs
+               scatsoa(icol) = (scatsoa(icol) + scath2o*hygrosoa(icol)/sumhygro)/sumscat
+               abssoa(icol)  = (abssoa(icol) + absh2o*hygrosoa(icol)/sumhygro)/sumabs
 
-            scatbc(icol)= (scatbc(icol) + scath2o*hygrobc(icol)/sumhygro)/sumscat
-            absbc(icol)  = (absbc(icol) +  absh2o*hygrobc(icol)/sumhygro)/sumabs
-
-            scatsslt(icol) = (scatsslt(icol) + scath2o*hygrosslt(icol)/sumhygro)/sumscat
-            abssslt(icol)  = (abssslt(icol) + absh2o*hygrosslt(icol)/sumhygro)/sumabs
+               scatbc(icol)= (scatbc(icol) + scath2o*hygrobc(icol)/sumhygro)/sumscat
+               absbc(icol)  = (absbc(icol) +  absh2o*hygrobc(icol)/sumhygro)/sumabs
 
+               scatsslt(icol) = (scatsslt(icol) + scath2o*hygrosslt(icol)/sumhygro)/sumscat
+               abssslt(icol)  = (abssslt(icol) + absh2o*hygrosslt(icol)/sumhygro)/sumabs
+            endif
 
             aodabsbc(icol) = aodabsbc(icol) + absbc(icol)*dopaer(icol)*(1.0_r8-palb(icol))
 
@@ -1149,7 +1150,6 @@ subroutine update_diags( is_coarse_dust )
             ! dmleung 20 Oct 2025 ++
             ! Then, all these diagnostics are outputted based on the modified dust AOD.
             ! We simply apply dopaer/dopaer0 (>1 for coarse mode) to the absorption diagnostics.
-            aodvis(icol) = aodvis(icol) + dopaer(icol)
             aodabs(icol) = aodabs(icol) + mass(icol,ilev) * pabs(icol) * dopaer(icol)/dopaer0(icol) ! dmleung
             extinct(icol,ilev) = extinct(icol,ilev) + dopaer(icol)*air_density(icol,ilev)/mass(icol,ilev)
             absorb(icol,ilev)  = absorb(icol,ilev) + air_density(icol,ilev) * pabs(icol) * dopaer(icol)/dopaer0(icol) ! dmleung
@@ -1161,6 +1161,8 @@ subroutine update_diags( is_coarse_dust )
 
          end if
 
+         aodvis(icol) = aodvis(icol) + dopaer(icol)
+
          if (ilev<=troplev(icol)) then
             aodvisst(icol) = aodvisst(icol) + dopaer(icol)
          end if