diff --git a/src/optics/LookUpTables.jl b/src/optics/LookUpTables.jl
index 3202adfad..6fd4c2f4b 100644
--- a/src/optics/LookUpTables.jl
+++ b/src/optics/LookUpTables.jl
@@ -876,17 +876,22 @@ function LookUpAerosolMerra(ds, ::Type{FT}, ::Type{DA}) where {FT <: AbstractFlo
     bnd_lims_wn = DA{FT}(Array(ds["bnd_limits_wavenumber"]))
     # map aerosol name to aerosol idx
     idx_aerosol = Dict(
-        "dust" => 1,
-        "sea_salt" => 2,
+        "dust1" => 1,
+        "sea_salt1" => 2,
         "sulfate" => 3,
         "black_carbon_rh" => 4,
         "black_carbon" => 5,
         "organic_carbon_rh" => 6,
         "organic_carbon" => 7,
+        map(i -> Pair("dust$i", i + 6), 2:5)...,
+        map(i -> Pair("sea_salt$i", i + 10), 2:5)...,
     )
     # map aerosol idx to its aeromass idx
     # please note that only "dust" and "sea salt" need aerosol sizes
-    idx_aerosize = Dict(1 => 1, 2 => 2)
+    idx_aerosol_keys = filter(collect(keys(idx_aerosol))) do k
+        occursin("dust", k) || occursin("sea_salt", k)
+    end
+    idx_aerosize = Dict(map(k -> Pair(idx_aerosol[k], idx_aerosol[k]), idx_aerosol_keys))
     return LookUpAerosolMerra(
         dims,
         size_bin_limits,
diff --git a/src/optics/aerosol_optics.jl b/src/optics/aerosol_optics.jl
index febe13258..6f0945d98 100644
--- a/src/optics/aerosol_optics.jl
+++ b/src/optics/aerosol_optics.jl
@@ -84,18 +84,29 @@ band number (`ibnd`), aerosol mass (`aeromass`), aerosol size (`aerosize`), and
 function compute_lookup_aerosol(lkp_aero, ibnd::Int, aero_mass, aero_size, rh::FT, glay) where {FT}
     τ_cum, τ_ssa_cum, τ_ssag_cum = FT(0), FT(0), FT(0)
 
-    if aero_mass[1, glay] > FT(0)
-        τ, τ_ssa, τ_ssag = compute_lookup_dust_props(lkp_aero, ibnd, aero_mass[1, glay], aero_size[1, glay])
-        τ_cum += τ
-        τ_ssa_cum += τ_ssa
-        τ_ssag_cum += τ_ssag
+    for i_aero_size in (1, 8, 9, 10, 11)
+        if aero_mass[i_aero_size, glay] > FT(0)
+            τ, τ_ssa, τ_ssag =
+                compute_lookup_dust_props(lkp_aero, ibnd, aero_mass[i_aero_size, glay], aero_size[i_aero_size, glay])
+            τ_cum += τ
+            τ_ssa_cum += τ_ssa
+            τ_ssag_cum += τ_ssag
+        end
     end
 
-    if aero_mass[2, glay] > FT(0)
-        τ, τ_ssa, τ_ssag = compute_lookup_sea_salt_props(lkp_aero, ibnd, aero_mass[2, glay], aero_size[2, glay], rh)
-        τ_cum += τ
-        τ_ssa_cum += τ_ssa
-        τ_ssag_cum += τ_ssag
+    for i_aero_size in (2, 12, 13, 14, 15)
+        if aero_mass[i_aero_size, glay] > FT(0)
+            τ, τ_ssa, τ_ssag = compute_lookup_sea_salt_props(
+                lkp_aero,
+                ibnd,
+                aero_mass[i_aero_size, glay],
+                aero_size[i_aero_size, glay],
+                rh,
+            )
+            τ_cum += τ
+            τ_ssa_cum += τ_ssa
+            τ_ssag_cum += τ_ssag
+        end
     end
 
     if aero_mass[3, glay] > FT(0)