From 3d82b3a6ad2dcb0843e752616f7f761820a1a1aa Mon Sep 17 00:00:00 2001 From: Melissa Sulprizio Date: Thu, 19 Aug 2021 12:27:06 -0400 Subject: [PATCH] Fix bug in implementation of LUO_WETDEP option Following the benchmarking of GEOS-Chem 13.2.0 with the Luo et al. (2020) wet deposition scheme, Gan Luo noticed a bug in the code. He wrote: Simulated sulfate mass concentration looks lower than what I expected. I checked https://github.com/geoschem/geos-chem/blob/13.2.0-beta.0/GeosCore/sulfate_mod.F90 It seems that we missed some switches for Non-volatile aerosol concentration calculation: (1) At line 5142 D = (2.e+0_fp*SO4nss) - (TNA+2.e+0_fp*TDCA), it should be: #ifdef LUO_WETDEP D = (1.5e+0_fp*SO4nss) - (TNA+2.e+0_fp*TDCA) #else D = (2.e+0_fp*SO4nss) - (TNA+2.e+0_fp*TDCA) #endif (2) At line 5156 D = (2.e+0_fp * SO4nss) - TNA), it should be: #ifdef LUO_WETDEP D = (1.5e+0_fp * SO4nss) - TNA #else D = (2.e+0_fp * SO4nss) - TNA #endif Switching from 2.e+0_fp * SO4nss to 1.5e+0_fp * SO4nss is following the reasons introduced in Luo et al. (2020). Signed-off-by: Melissa Sulprizio --- GeosCore/sulfate_mod.F90 | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/GeosCore/sulfate_mod.F90 b/GeosCore/sulfate_mod.F90 index 9791dbaef..fa87709a0 100644 --- a/GeosCore/sulfate_mod.F90 +++ b/GeosCore/sulfate_mod.F90 @@ -5139,7 +5139,11 @@ SUBROUTINE GET_HPLUS( SO4nss, TNH3, TNO3, SO2, CL, TNA, TDCA, TFA, & ! then all Ca is dissolved else [Ca2+] varies with [H+] IF ( fCa .ge. TDCA ) THEN ! Non-volatile aerosol concentration [M] +#ifdef LUO_WETDEP + D = (1.5e+0_fp*SO4nss) - (TNA+2.e+0_fp*TDCA) +#else D = (2.e+0_fp*SO4nss) - (TNA+2.e+0_fp*TDCA) +#endif ! Define f(x) f = D - nHPLUS + Kw/nHPLUS + fHCO3 + 2.e+0_fp * & @@ -5153,7 +5157,11 @@ SUBROUTINE GET_HPLUS( SO4nss, TNH3, TNO3, SO2, CL, TNA, TDCA, TFA, & ELSE ! Non-volatile aerosol concentration [M] +#ifdef LUO_WETDEP + D = (1.5e+0_fp * SO4nss) - TNA +#else D = (2.e+0_fp * SO4nss) - TNA +#endif ! Define f(x) f = D - nHPLUS + Kw/nHPLUS + fHCO3 + 2.e+0_fp * fCO3 + &