Aerosol-only simulation
Previous | Next | Guide to GEOS-Chem simulations
- Simulations overview
- Mechanisms for full-chemistry simulations (e.g. Standard, Tropchem, etc.)
- Aerosol-only simulation
- CH4 simulation
- CO2 simulation
- Hg simulation
- POPs simulation
- Tagged CO simulation
- Tagged O3 simulation
- TransportTracers simulation
On this page we describe the aerosol-only (a.k.a. offline aerosol) simulation.
Description
The aerosol simulation is an offline simulation for aerosol tracers only. It uses archived monthly mean OH, NO3, O3 and total nitrate concentrations archived from a previous full-chemistry simulation (more on that below), as well as production and loss rates for H2O2. This simulation does not provide "tagged" capabilities, but reduces the suite of tracers from full chemistry.
NOTES:
- The aerosol-only simuation is currently functional in GEOS-Chem 13 and GEOS-Chem 14.
- There is currently no aerosol-only run directory for GCHP. Interested users are encouraged to make this modification on their own.
- The oxidant fields should be updated to use output from a recent GEOS-Chem version.
Assumptions
- OH concentrations are archived from the most recent 10-year benchmark simulation.
- O3, NO3 and total nitrate (HNO3+NIT) concentrations, as well as production rates and photolysis rates for H2O2 are archived from the most recent 10-year benchmark simulation.
Practicalities
As with all other Offline chemistry simulations, the GEOS-Chem user community shall be responsible for the scientific content and validation of the aerosol-only simulation.
Tracer list
GEOS-Chem v9-02 and later versions
The SOA simulation was updated in GEOS-Chem v9-02o to include a better tracer lumping scheme, as shown in Figure 1 of Pye et al. 2010.
The offline aerosol is simulation type 10. For a full set of aerosol tracers (based on the 100-tracer full-chemistry SOA simulation), the input.geos should look like this:
Type of simulation : 10 Number of Tracers : 47 Tracer Entries -------> : TR# Name g/mole Tracer Members; () = emitted Tracer #1 : 1 DMS 62.00 Tracer #2 : 2 SO2 64.00 Tracer #3 : 3 SO4 96.00 Tracer #4 : 4 SO4s 96.00 Tracer #5 : 5 MSA 96.00 Tracer #6 : 6 NH3 17.00 Tracer #7 : 7 NH4 18.00 Tracer #8 : 8 NIT 62.00 Tracer #9 : 9 NITs 62.00 Tracer #10 : 10 H2O2 34.00 Tracer #11 : 11 BCPI 12.00 Tracer #12 : 12 OCPI 12.00 Tracer #13 : 13 BCPO 12.00 Tracer #14 : 14 OCPO 12.00 Tracer #15 : 15 DST1 29.00 Tracer #16 : 16 DST2 29.00 Tracer #17 : 17 DST3 29.00 Tracer #18 : 18 DST4 29.00 Tracer #19 : 19 SALA 36.00 Tracer #20 : 20 SALC 36.00 Tracer #21 : 21 MTPA 136.23 Tracer #22 : 22 LIMO 136.23 Tracer #23 : 23 MTPO 136.23 Tracer #24 : 24 TSOG1 150.00 Tracer #25 : 25 TSOG2 150.00 Tracer #26 : 26 TSOG3 150.00 Tracer #27 : 27 TSOG0 150.00 Tracer #28 : 28 TSOA1 150.00 Tracer #29 : 29 TSOA2 150.00 Tracer #30 : 30 TSOA3 150.00 Tracer #31 : 31 TSOA0 150.00 Tracer #32 : 32 ISOG1 150.00 Tracer #33 : 33 ISOG2 150.00 Tracer #34 : 34 ISOG3 150.00 Tracer #34 : 35 ISOA1 150.00 Tracer #36 : 36 ISOA2 150.00 Tracer #37 : 37 ISOA3 150.00 Tracer #38 : 38 BENZ 12.00 (6C) Tracer #39 : 39 TOLU 12.00 (7C) Tracer #40 : 40 XYLE 12.00 (8C) Tracer #41 : 41 ASOG1 150.00 Tracer #42 : 42 ASOG2 150.00 Tracer #43 : 43 ASOG3 150.00 Tracer #44 : 44 ASOAN 150.00 Tracer #45 : 45 ASOA1 150.00 Tracer #46 : 46 ASOA2 150.00 Tracer #47 : 47 ASOA3 150.00
This list can be reduced by turning off any aerosol species (eg. SOA, dust, SS, etc). You may also run without the secondary organic aerosols (MTPA, LIMO, MTPO, TSOG0–3, TSOA0–3, ISOG1–3, ISOA1–3, ASOG1–3, ASOA1–3, ASOAN) if you wish (but we recommend that you use them).
--Melissa Sulprizio 12:51, 5 November 2013 (EST)
Previous issues that have now been resolved
Fixed undefined molecular weight of HNO3 in routine SEASALT_CHEM
This fix was included in v11-01j and approved on 03 Dec 2016
In routine SEASALT_CHEM (in GeosCore/sulfate_mod.F), the MW_HNO3 variable was undefined for aerosol-only simulations, which do not use HNO3 as a defined species. This issue was detected by a unit test using the GNU Fortran compiler.
To fix this issue, we have added the following block of code, which defines MW_HNO3 whether or not HNO3 is a defined species:
! Get the molecular weight of HNO3 from the species database
! if it is defined, otherwise set it manually (bmy, 10/11/16)
IF ( id_HNO3 > 0 ) THEN
MW_HNO3 = State_Chm%SpcData(id_HNO3)%Info%emMW_g
ELSE
MW_HNO3 = 63.0_fp
ENDIF
NOTE: This is just a quick fix. Ideally, we will want to declare HNO3 as a non-advected species in the GEOS-Chem species database for these simulationns.
--Bob Yantosca (talk) 16:47, 11 October 2016 (UTC)
Error in ISOROPIAII when sulfate aerosols are turned off
This update was tested in the 1-month benchmark simulation v9-02r and approved on 14 Nov 2013.
Chris Butenhoff wrote:
- I set ONLINE SULFATE AEROSOLS = F and removed the sulfate aerosols from the tracer list. However I now get the error "IDTSO4 is undefined" from isoropia11_mod.F (line 207).
For full-chemistry simulations, we only call routine DO_ISOROPIAII if sulfate aerosols are used (i.e. LSULF = T). However, no such check exists when running the offline aerosol simulation. This was probably an oversight and we should add the following fix to routine DO_CHEMISTRY (in GeosCore/chemistry_mod.F):
!*** AEROSOL THERMODYNAMIC EQUILIBRIUM ***
IF ( LSULF ) THEN
IF ( LSSALT ) THEN
#if !defined( NO_ISORROPIA )
! ISOROPIA takes Na+, Cl- into account
CALL DO_ISOROPIAII
& ( am_I_Root, Input_Opt, State_Met, State_Chm, RC )
#endif
ELSE
! RPMARES does not take Na+, Cl- into account
! (skip for crystalline & aqueous offline run)
IF ( .not. LCRYST ) THEN
CALL DO_RPMARES( am_I_Root, Input_Opt,
& State_Met, State_Chm, RC )
ENDIF
ENDIF
ENDIF
--Bob Y. 15:29, 14 November 2013 (EST)