Physical properties of GEOS-Chem species

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Overview

The GEOS-Chem Support Team has created a common data structure (aka the "GEOS-Chem species database") that stores all of the various physical properties for GEOS-Chem species. Formerly, these properties were defined (and and sometimes etimes redefined) in several locations in the code.

For example, the effective Henry's law value Heff is calculated differently in the wet deposition module than in the dry deposition module. The GEOS-Chem wet deposition module assumes a pH value of 4.5 for rainwater, and thus uses a set of Henry’s law constants that are appropriate for this pH. On the other hand, the GEOS-Chem dry deposition module assumes a pH of 7 for water, and therefore uses a different set of Henry’s law constants. Keeping two independent sets of Henry’s law constants can lead to confusion.

In the GEOS-Chem v10-01, Christoph Keller implemented a new GEOS-Chem module that can compute Heff for each species as a function of pH and the species-specific Henry’s law constants K0, CR, and pKA. These Henry’s law constants can be obtained from the literature (cf. Sander, Atmos. Chem. Phys. 15, 4399-4381, 2015, download from this site, or similar references). We would like to use Christoph’s new module to compute Heff in a consistent way everywhere in GEOS-Chem.

We now store these Henry's law constants together with other relevant physical parameters such as molecular weight, density, aerosol radius, reactivity factor for drydep (F0), etc. for each species. Keeping all of these physical properties in a single data structure will streamline the code and help to reduce confusion.

Phase 1 of the GEOS-Chem species database was completed in GEOS-Chem v11-01d. Phase 2 was completed in GEOS-Chem v11-01e. Further work is slated for GEOS-Chem v11-02.

--Bob Yantosca (talk) 19:33, 30 November 2016 (UTC)

Henry's law

Definition of Henry's law constants

The table lists the Henry's law constants for each species as defined in the dry deposition and wet deposition modules in GEOS-Chem v11-01 and prior versions. These constants are:

Constant Units Description Also known as
Hstar M atm-1 This is the Henry's law solubility constant (for T = 298.15 K and pH = 7) that is used in the dry deposition module drydep_mod.F.
  • Hcp
  • Kstar298
K0 M atm-1 This is the Henry's law solubility constant (for T = 298.15 K and pH = 4.5) that is currently used in the GEOS-Chem wet deposition module wetscav_mod.F.
  • Hcp
  • Kstar298
CR K This is the Henry's law volatility constant that is currently used in the GEOS-Chem wet deposition module wetscav_mod.F.
  • H_298R
  • d(ln Hcp) / d(1/T)
pKa 1 Henry's law correction factor for pH. This is used by the new CALC_KH and CALC_HEFF routines from henry_mod.F.

--Bob Y. (talk) 16:25, 6 October 2015 (UTC)

Henry's law constants used in GEOS-Chem

Note that because the GEOS-Chem dry deposition module (drydep_mod.F) and the wet deposition module (wetscav_mod.F) were developed (and modified) independently of each other, the Henry's law solubility constants often do not match. This is mostly historical baggage. We hope that this update to GEOS_Chem will ensure that dry deposition and wet deposition use the same Henry's law constants.

For dry deposition, we assume a pH value of 7. For wet deposition, we assume a pH value of 4.5.

Species Hstar
[M atm-1]
K0
[M atm-1]
CR
[K]
References
ACET 1.00e+05 2.70e+01 5300
  • HSTAR: Original value from drydep_mod.F
  • NOTE: ACET now wet deposits in GEOS-Chem v11-01d
ALD2 1.10e+01 1.10e+01 6300
ASOG1
ASOG2
ASOG3
1.00e+5 1.00e+5 6039
  • Havala Pye
Br2 7.6e-01 7.6e-01 3720
  • Yang et al 2005, Table 2 (assuming T = 298 K)
BrNO3 1.00e+20
  • Assume an infinite value of HSTAR (cf. Sander)
CH2O 6.00e+03 3.00e+03 7200
DMS 4.80e-01 3100
EOH 1.90e+02 1.90e+02 6600
GLYC 4.10e+04 4.10e+04 4600
  • Betterton & Hoffman 1988
GLYX 3.6e+05 3.6e+05 7200
  • Betterton & Hoffman 1988
H2O2 1.00e+05 8.30e+04 7400
  • HSTAR: This was the value that was originally in drydep_mod.F
  • K0, CR: cf Jacob et al 2000, Table 1
HAC 2.90e+03 2.93e+03 0
  • Spaulding et al 2002
HBr 7.10e+15 7.10e+13 10200
  • Set HSTAR to 7.1e+15, consistent with p-TOMCAT (cf. Dean 1992). Assumes a pH of 7 for the plant stomata.
  • K0 and CR are estimated by Yang et al 2005.
  • HBr has a large effective Henry's Law Constant, similar to HCl and HNO3, which have retention fractions (RFs) of 1 for wet deposition. RFs have not been measured for HBr; however, Stuart and Jacobson [2003] suggest that species with large Hstar's should have RF's of about 1.
HCl 2.05e+06 7.10e+15 11000
  • HSTAR: Seb Eastham (17 Apr 2013)
  • K0, CR: Yang et al 2005
Hg2 1.00e+14 1.40e+06 8400
  • K0, CR: Lindqvist & Rhode 1985
  • HSTAR: Set to 1e+14 by Helen Amos (23 Sep 2011)
HNO3 1.0e+14
  • Original value from drydep_mod.F
HOBr 6.10e+03 6.10e+03 6014
  • Set HSTAR and Hcp = 6.10e+3, which is consistent with p-TOMCAT (cf. Freznel et al 1998)
  • McGrath and Rowland, 1994 says dH_sol for HOBr = - 50 kJ/mol (- 12 kcal/mol)
  • Acid dissociation constant in Heff is small (1.5e-9), reported by Haag and Holne [1983]
IEPOX 1.e3+08 1.3e+08 0
  • F. Paulot??
ISOG1
ISOG1
ISOG3
1.00e+05 1.00e+05 6039
  • Havala Pye
ISOPN 1.7e+04 1.7e+04 9200
  • NOTE: ISOPN dry deposits as ISOPND and ISOPNB
  • HSTAR, K0, CR taken from Ito 2007
LIMO 7.00e-02 7.00e-02 0
  • ??, maybe Havala Pye
MACR 6.50e+00
  • R. Sander (year not specified, probably 1999)
MAP 8.4e+02 8.4e+02 5300
  • R. Sander (year not specified, probably 1999)
MGLY 8.4e+02 8.4e+02 5300
  • Betterton & Hoffmann 1988
MOBA 2.30e+04 6300
  • Based on methacrylic acid with acetic acid T dependence (Fabien Paulot)
  • pKa = 4.1, pH =5
MMN 1.7e+04 1.7e+04 9200
  • MMN dry deposits as MACRN + MVKN
  • Ito 2007
MP
(aka CH3OOH)
0.0e+00 3.10e+2 5200
MTPA 4.90e+02 4.90e+02 0
  • Use K0 = 0.049 for all pinene (Sander 1999)
MTPO 4.90e+02 4.90e+02 0
  • Use K0 = 0.049 for all pinene (Sander 1999)
MVK 4.40e+01
  • R. Sander (year not specified, probably 1999)
N2O5 0.0e+00
  • N2O2 uses the same drydep velocity as HNO3, so set HSTAR = 0
NH3 2.00e+04 3.30e+06 4100
  • ?
NO2 1.00e-02
  • ? (original value from drydep_mod.F)
O3 1.00e-02
  • ? (original value from drydep_mod.F)
OPOG1
OPOG2
1.00e+05 1.00e+05 6039
  • Havala Pye
PAN 3.60e+00
  • ? (original value from drydep_mod.F)
PMN 0.00+00
  • PMN uses the same drydep velocity as PAN, so set HSTAR = 0
POG1
POG2
9.5e+00 9.5e+00 4700
  • Based on phenanthrene (cf Sander 1999)
  • NOTE: Make POG hydrophobic (cf Havala Pye)
POPG (PHE) 2.35e+01 2.35e+01 47
  • HSTAR and K0: Ma et al 2010 (J. Chem Eng. Data)
  • CR: Scharzenbach 2003, p. 200
  • NOTE: In the code HSTAR & K0 are computed as ( 1.0 / 1.74e-03 ) * 0.0409 = 23.505
POPG (PYR) 7.61e+01 7.61e+01 43
  • HSTAR and K0: Ma et al 2010 (J. Chem Eng. Data)
  • CR: Scharzenbach 2003, p. 200
  • NOTE: In the code HSTAR & K0 are computed as ( 1.0 / 5.37e-04 ) * 0.0409 = 76.163
POPG (BaP) 1.23e+03 1.23e+03 43
  • HSTAR and K0: Ma et al 2010 (J. Chem Eng. Data)
  • CR: Scharzenbach 2003, p. 200
  • NOTE: In the code HSTAR & K0 are computed as ( 1.0 / 3.10e-05 ) * 0.0409 = 1319.354
PPN 0.00+00
  • PPN uses the same drydep velocity as PAN, so set HSTAR = 0
PROPNN 1.0e+03 1.0e+03 0
  • Nitrooxyacetone in Sander 1999
R4N2 0.00+00 R4N2
  • Uses same dry deposition velocity as PAN, so set HSTAR = 0
RIP 1.7e+06 1.7e+06 0
  • US EPA 2011
SO2 1.00e+05
  • ?
TSOG0
TSOG1
TSOG2
TSOG3
1.00e+05 1.00e+05 6039
  • Havala Pye

--Bob Y. (talk) 18:52, 6 October 2015 (UTC)

Proposed list of Henry's law constants from the literature

Katie Travis has put together a proposed list of updates to the Henry's law constants for GEOS-Chem species. As of this writing (August 28, 2015), these updates have not yet been implemented into GEOS-Chem, but will be soon (pending approval from the Oxidants and Chemistry Working Group). The updated constants were mostly taken from the Sander, 2015 compilation, and corresponding references.

Proposed K0 [mol m-3 Pa-1]
Proposed new value for the Henry's law solubility constant (for T = 298.15 K).
  • NOTE: Sander 2015 now lists K0 in units of mol m-3 Pa-1.
  • To compare this to the K0 values currently used in GEOS-Chem, you must use this conversion factor: 1 M atm-1 = 9.86923 x 10-3 mol m-3 Pa-1
Proposed CR [K]
Proposed new value for the Henry's law volatility constant.
Proposed pKa
Proposed new pH Correction factor.
Species Proposed K0
[mol m-3 Pa-1]
Proposed CR
[K]
Reference Notes Proposed pKa
[1]
Reference
NO 1.90E-05 1600 Warneck and Williams [2012]
O3 1.10E-04 2800 Sander et al [2011]
PAN 2.90E+02 5700 Warneck and Williams [2012]
CO 9.70E-06 1300 Warneck and Williams [2012]
ALK4 1.20E-05 3100 Sander et al [2011] As butane
ISOP 3.40E-04 4400 Leng et al [2013]
HNO3 2.10E+03 8700 Lelieveld and Crutzen [1991]
H2O2 4.93E+05 6600 Nguyen et al [2014] (Table S4); Warneck and Williams [2012] 11.6 Anglada et al [2015]
ACET 2.70E-01 5500 Sander et al [2011]
MEK 1.80E-01 5700 Sander et al [2011]
ALD2 1.30E-01 5900 Sander et al [2011]
RCHO 9.50E-02 6200 Sander et al [2011] As butanal
MVK 2.60E-01 4800 Ji and Evans [2007]
MACR 4.80E-02 4300 Ji and Evans [2007]
PMN 1.70E-02 Kames and Schurath [1995]
PPN 2.90E-02 Kames and Schurath [1995]
R4N2 1.00E-02 5800 Sander et al [2011] as 1-butyl nitrate
PRPE 7.30E-05 3400 Wilhelm et al [1997] as propene
C3H8 1.50E-05 2700 Sander et al [2011]
CH2O 3.20E+01 6800 Warneck and Williams [2012]
C2H6 1.90E+05 2400 Sander et al [2011]
N2O5 2.10E-02 3400 Fried et al [1994]
HNO4 3.90E+01 8400 Leu and Zhang [1999]
MP 2.90E+00 5200 Warneck and Williams [2012]
DMS 4.80e-01 3100 De Bruyn et al [1995]
SO2 1.30E-02 2900 Sander et al [2011]
NH3 5.90E-01 4200 Sander et al [2011]
Br2 7.20E-03 4400 Sander et al [2011]
Br 3.40E-04 1800 Berdnikov and Bashin [1970]
BrO
HOBr 1.30E+00 4000 Sander et al [2011]; Mozurkewich [1995]
HBr 2.40E-01 370 Dean [1992]
BrNO2 3.00E-03
BrNO3
CHBr3 1.70E-02 5200 Sander et al [2011]
MPN
ISOPN 1.97E+04 Nguyen et al 2015 (Table S4)
MOBA 2.27E+02 -6.30E+03 Need reference from wetscav_mod.F
PROPNN 4.93E+03 Nguyen et al [2014] (Table S4)
HAC 7.70E+01 Lee and Zhou [1993]
GLYC 4.10E+02 4600 Betterton and Hoffman [1988]
MMN 1.97E+04 Nguyen et al [2014] (Table S4)
RIP 7.90E+05 0 Nguyen et al [2014] (Table S4)
IEPOX 7.60E+05 0 Nguyen et al [2014] (Table S4)
MAP 8.3 5300 Sander et al [2011]
NO2 1.20E-04 2400 Sander et al [2011]
NO3 3.80E-04 1900 Sander et al [2011]; Chameides (1986)
HNO2 4.80E-01 4800 Schwartz and White [1981]
ISN1 1.97E+04 Set to MMN/ISOPN
ETHLN 1.97E+04 Set to MMN/ISOPN
MGLY 3.20E+02 Zhou and Mopper [1990]
GLYX 4.10E+03 7500 Sander et al [2011]
HCOOH 8.80E+01 6100 Sander et al [2011]
ACTA 4.00E+01 6200 Sander et al [2011]
DHDN 1.97E+04 Set to MMN/ISOPN
LIM 4.80E-04 4600 Leng et al [2013]
API 2.90E-04 1800 Leng et al [2013]
MONIT 1.68E+02 9200 Browne et al [2014]
HONIT 2.65E+11 5487 Browne et al [2014]
HPALD 3.95E+02 Nguyen et al [2014] (Table S2)
MNO3 2.00E-02 4700 Sander et al [2011]
Hg2 1.40e+04 5300
POPG (PHE)
POPG (PYR)
POPG (BaP)

--Bob Y. (talk) 19:00, 6 October 2015 (UTC)

Computing the effective Henry's law constant

Christoph Keller has written a module (GeosUtil/henry_mod.F) to compute the effective Henry's law constant given the parameters listed above and the pH value. This module is used in the HEMCO emissions component in GEOS-Chem v10-01 and higher versions.

This computation requires three steps.

1. If the value of K0 for a given species from in the table above is in units of mol m-3 Pa-1, then convert this to M atm-1 by multiplying by 9.86923 x 10-3. The formulae below require Hcp in M atm-1.
2. Call routine CALC_KH in GeosUtil/henry_mod.F to compute the dimensionless liquid over gas Henry's law constant at a given temperature T . This routine uses the following formula:
     KH = K0 * EXP( CR * ( 1/T - 1/298.15 ) ) * R * T / ATM
where
  1. K0 is the Henry's law solubility constant, in M atm-1,
  2. CR is the Henry's law volatility constant, in K,
  3. T is the temperature in K,
  4. R is the universal gas constant = 8.3144621 J K-1 mol-1,
  5. ATM is the reference pressure at STP = 101.325 mPa, and
  6. 298.15 is the reference temperature (in K) at STP
3. Call routine CALC_HEFF in GeosUtil/henry_mod.F to compute the effective Henry's law constant taking into account the pH value. This applies a correction term to the KH value that we computed in Step 2. This routine uses the formula:
     IF ( pH > 0 ) THEN
        HEFF = KH * 1 + 10**( pH - pKa )
     ELSE
        HEFF = KH
     ENDIF 
where
  1. KH is the dimensionless liquid over gas Henry's constant we computed in Step 2,
  2. pKa is the value of pKa listed in the table above,
  3. pH is the desired pH value, and
  4. HEFF is the dimensionless liquid over gas Henry's law constant, adjusted for pH
NOTES:
  1. It should be noted that the correction term calculated here is from a 'acid perspective', i.e. for compounds with the acid being in the gaseous phase. The correction term reads 1 + 10**( -pH + pKa ) for compounds with the base in the gas phase (e.g. ammonia).
  2. The correction term becomes more complicated for compounds with more than two equilibrium compounds that are relevant under the current conditions (e.g. CO2)
  3. We ignore any temperature dependencies of pKa for now.

NOTE: In GEOS-Chem v10-01 and prior versions, the wet deposition module calls the older routine COMPUTE_L2G, which does the same computation, as CALC_KH, but is written in a slightly different way. We will replace COMPUTE_L2G with the CALC_KH and CALC_HEFF so that GEOS-Chem uses the the same Henry's law routines everywhere.

--Bob Y. (talk) 19:12, 6 October 2015 (UTC)

Dry deposition

The table below shows the various dry-deposition parameters for both gas-phase and aerosol species. The quantities in each column correspond to fields of the Species derived type, as described on our GEOS-Chem species database wiki page.

Aerosol Species Parameters Gas-Phase Species Parameters
Species MW_g
[g mol-1]
EmMW_g
[g mol-1]
Molec
Ratio

[1]
Radius
[m]
Density
[kg m-3]
DD_Aero
Drydep

[1]
DD_Dust
Drydep

[1]
DD_Dvz
AerSnow

[cm s-1]
DD_Dvz
MinVal

[cm s-1]
DD_F0
[1]
References
ACET 58.08 12 3 - - - - - - 1.0 Karl et al [2010]
ALD2 44.05 12 2 - - - - - - 1.0 Karl et al [2010}??
ALK4 58.12 12 4 - - - - - - 1.0 From drydep_mod.F
ASOAN
ASOA1
ASOA2
ASOA3
150 150 - - - - - 0.03 - - -
ASOG1
ASOG2
ASOG3
150 150 - - - - - - - 0.0
BCPI
BCPO
12.01 12 1 - - - - 0.03 - - -
Be7 201 201 - - - - - 0.03 - - -
Br2 160 160 - - - - - - - 0.0 -
BrNO3 142 142 - - - - - - - 0.0 -
CH2O 30 30 - - - - - - - 1.0 Karl et al [2010]?
DST1
DSTAL1
NITD1
SO4D1
29 29 - 7.30e-07 2500 NO YES - - - -
DST2
DSTAL2
NITD2
SO4D2
29 29 - 1.40e-06 2650 NO YES - - - -
DST3
DSTAL3
NITD3
SO4D3
29 29 - 2.40e-06 2650 NO YES - - - -
DST4
DSTAL4
NITD4
SO4D4
29 29 - 4.5e-06 2650 NO YES - - - -
GLYC 60 60 - - - - - - - 1.0 Karl et al [2010]
GLYX 58 58 - - - - - - - 1.0 -
H2O2 34 34 - - - - - - - 1.0 From drydep_mod.F
H2SO4 98 98 - - - - - - - 0.0
HAC 74 74 - - - - - - - 1.0 Karl et al [2010]
HBr 81 81 - - - - - - - - -
HCl 36 36 - - - - - - - 0.0
Hg0 201 201 - - - - - - - 1.0e-5
HgP 201 201 - - - - - 0.03 - - -
Hg2 201 201 - - - - - - - 0.0
HNO3 63 63 - - - - - - - 0.0 From drydep_mod.F
HOBr 97 97 - - - - - - - 0.0 -
IEPOX 118 118 - - - - - - - 1.0 Karl et al [2010]
ISOPN 147 147 - - - - - - - 1.0 Karl et al [2010]
ISOA1
ISOA2
ISOA3
150 150 - - - - - 0.03 - 0.0 -
ISOG1
ISOG2
ISOG3
150 150 - - - - - - - 0.0 -
LIMO
MTPA
MTPO
136.23 136.23 - - - - - - - 0.0
MACR 70 70 - - - - - - - 1.0 Karl et al [2010]?
MAP 76 76 - - - - - - - 1.0 Karl et al [2010]
MMN 149 149 - - - - - - - 1.0 Karl et al [2010]
MOBA 114 114 - - - - - - - 1.0 Karl et al [2010]
MOPI 12.01 12 1 - - - - 0.03 - - -
MOPO 12.01 12 1 - - - - 0.03 - - -
MSA 96 96 - - - - - 0.03 0.01 snow
0.01 land
- -
N2O5 63 63 - - - - - - - 0.0 See Note 1 below
NH3 17 17 - 0.0 - - - 0.03 0.2 snow
0.3 land
- -
NH4 18 18 - - - - - 0.03 0.01 snow
0.01 land
- -
MVK 70 70 - - - - - - - 1.0 Karl et al [2010]?
NIT 62 62 - - - - - 0.03 0.01 snow
0.01 land
- -
NITs 31.4 31.4 - 4.25e-6 2200 YES NO - - - -
NO2 118 118 - - - - - - - 0.1 Karl et al [2010]
OCPI
OCPO
OPOA1
OPOA2
POA1
POA2
12.01 12 1 - - - - 0.03 - - -
O3 48 48 - - - - - - - 1.0 Karl et al [2010]
OPOG1
OPOG2
12.01 12 1 - - - - - - 0.0
PAN 121 121 - - - - - - - 1.0 Karl et al [2010]
Pb210 210 210 - - - - - 0.03 - - -
PMN 121 121 - - - - - - - 1.0 See Note 2 below
POG1
POG2
12.01 12 1 - - - - - - 0.0 Karl et al [2010]?
POPPBCPI
POPBCPO
POPPOCPI
POPOCPO
(PHE)
178.23 178.23 - - - - - 0.03 - - -
POPPBCPI
POPBCPO
POPPOCPI
POPOCPO
(PYR)
202.25 202.25 - - - - - 0.03 - - -
POPPBCPI
POPBCPO
POPPOCPI
POPOCPO
(BaP)
252.31 252.31 - - - - - 0.03 - - -
POPG (PHE) 178.23 178.23 - - - - - - - 0.0
POPG (PYR) 202.25 202.25 - - - - - - - 0.0
POPG (BaP) 252.31 252.31 - - - - - - - 0.0
PPN 121 121 - - - - - - - 1.0 See Note 2 below
PROPNN 119 119 - - - - - - - 1.0 Karl et al [2010]
R4N2 121 121 - - - - - - - 1.0 See Note 2 below
RIP 118 118 - - - - - - - 1.0 Karl et al [2010]
SALA 31.4 31.4 - 2.55e-7 2200 YES NO - - - -
SALC 31.4 31.4 - 4.25e-6 2200 YES NO - - - -
SO2 64 64 - - - - - 0.03 0.2 snow
0.3 land
0.0 -
SO4 96 96 - - - - - 0.03 0.01 snow
0.01 land
- -
SO4s 31.4 31.4 - 4.25e-6 2200 YES NO - - - -
TSOA0
TSOA1
TSOA2
TSOA3
150 150 - - - - - 0.03 - 0.0 -
TSOG0
TSOG1
TSOG2
TSOG3
150 150 - - - - - - - 0.0 -
TOMAS microphysics species Aerosol Species Parameters Gas-Phase Species Parameters
NK1-NK40 1 1 - - - - - 0.03 - - -

NOTES:

  1. N2O5 uses the same dry deposition velocity (Vd) as HNO3. In GEOS-Chem v11-01, we now compute Vd(N2O5) explicitly. We therefore have to assign to N2O5 the same F0, Hstar_old, and MW_g values that HNO3 uses in order for the computation of Vd to be done correctly.
  2. PMN, PPN, and R4N2 all use the same dry deposition velocity (Vd) as PAN. In GEOS-Chem v11-01, we now compute Vd(PMN), Vd(PPN), and Vd(R4N2) explicitly. We therefore have to assign to PMN, PPN, and R4N2 the same F0, Hstar_old, and MW_g values that PAN uses in order for the computations to be done correctly.

--Bob Yantosca (talk) 20:55, 19 May 2016 (UTC)

Discrepancies found in the dry deposition module

This update was validated with 1-month benchmark v11-01e (approved 04 Jan 2016).
Some of these issues had already been corrected in v11-01d (approved 12 Dec 2015).

During the implementation of the species database of physical properties into GEOS-Chem, we discovered several issues with how species were defined in the dry deposition module drydep_mod.F.

Species Issue Solution Status
ACET
  • Previously, drydep_mod.F used XMW = 0.058 kg/mol for the MW of ACET.
  • But the MW of ACET as defined in the GEOS-Chem species database = 58.08 g/mol = 0.05808 kg/mol.
  • Obtain the MW of ACET (= 58.08 g/mol = 0.05808 kg/mol) from the GEOS-Chem species database.
  • Assign this value to XMW in drydep_mod.F.
ALD2
  • Previously, drydep_mod.F used XMW = 0.044 kg/mol for the MW of ALD2.
  • But the MW of ALD2 as defined in the GEOS-Chem species database = 44.05 g/mol = 0.04405 kg/mol.
  • Obtain the MW of ALD2 (= 44.05 g/mol = 0.04405 kg/mol) from the GEOS-Chem species database.
  • Assign this value to XMW in drydep_mod.F.
MTPO
  • Previously, drydep_mod.F used XMW = 0.136 kg/mol for the MW of MTPO.
  • But the actual MW of MTPO as defined in the GEOS-Chem species database = 136.23 g/mol = 0.13623 kg/mol.
NITs
  • The dry deposition species name (i.e. stored in the DEPNAME array of drydep_mod.F was NITS (all caps).
  • But the given species name used throughout GEOS-Chem is NITs (lowercase "s").
  • Assign the name NITS to the DEPNAME array.
NITs
  • Previously, drydep_mod.F used XMW = 0.036 kg/mol for the MW of NITs.
    • This corresponded to the molecular weight of coarse sea-salt aerosol (SALC).
    • NOTE: Because NITs is internally mixed, it is appropriate to give NITs the MW of SALC.
  • But the MW of SALC was changed to 0.0314 kg/mol in GEOS-Chem v9-02.
POPG
POPPOCPI
POPPOCPO
POPPBCPI
POPPBCPO
  • The molecular weights as listed in the TRACER MENU section of input.geos often do not match the POP_MW setting in the POPS MENU.
  • For example:
    • PHE: MW = 178.23 but POP_MW = 178
    • PYR: MW = 202.25 but POP_MW = 202
    • BaP: MW = 252.31 but POP_MW = 252
  • Edit the input.geos files (i.e. in the GEOS-Chem Unit Tester) to ensure that the POP_MW value is the same as the molecular weight listed in the TRACER MENU section..
POPG
  • In routine INIT_DRYDEP, KOA is multiplied by 0.0409 but this may lead to a loss of precision.
  • Multiply KOA by 0.0409d0 to enforce REAL*8 precision.
  • In v11-01d and higher versions, this is now done in module Headers/species_database_mod.F90.
SALA
SALC
  • SALA and SALC have historically used MW's of 36 g/mol.
    • These values appear to have been used since at least v7-02-03 (Feb 2005).
  • In GEOS-Chem v9-02 (03 Mar 2015), the MW's of SALA and SALC were changed from 36 g/mol to 31.4 g/mol.
  • However, the new MW's of SALA and SALC were only added to the input.geos files, but not to the XMW variable of drydep_mod.F.
    • Therefore, since GEOS-Chem v9-02, dry deposition of SALA and SALC has been computed using the incorrect molecular weights.
  • Obtain the MW's of SALA and SALC (= 31.4 kg/mol = 0.0314 kg/mol) from the species database object.
  • Assign these values to XMW in drydep_mod.F.
SO4s
  • The dry deposition species name (i.e. stored in the DEPNAME array of drydep_mod.F was SO4S.
  • But the given species name used throughout GEOS-Chem is SO4s (lowercase "s").
  • Assign the name SO4S to the DEPNAME array.
SO4s
  • Previously, drydep_mod.F used XMW = 0.036 kg/mol for the MW of SO4s.
    • This corresponded to the molecular weight of coarse sea-salt aerosol (SALC).
    • NOTE: Because SO4s is internally mixed, it is appropriate to give SO4s the MW of SALC.
  • But the MW of SALC was changed to 0.0314 kg/mol in GEOS-Chem v9-02.


NOTE: ALK4 had been included in this table, but it is not a dry-deposited species. We have therefore removed ALK4 from the above table. Thanks to Prasad Kasibhatla for pointing out the error.

--Bob Yantosca (talk) 17:13, 22 February 2016 (UTC)

Wet deposition

The table below shows the various wet deposition parameters for both gas-phase and aerosol species. The quantities in each column correspond to fields of the Species derived type, as described on our GEOS-Chem species database wiki page.

Aerosol Species Parameters Gas-phase Species Parameters
Species MW_g
[g mol-1]
EmMW_g
[g mol-1]
Molec
Ratio

[1]
WD_Coarse
Aer

[?]
WD_Aer
ScavEff

[1]
WD_KcScaleFac
[1]
WD_RainoutEff
[1]
WD_Ret
Factor

[1]
References
T < 237 K 237 K <= T < 258 K T > 258 K T < 237 K 237 K <= T < 258 K T > 258 K
ACET 58.08 12 3 - - - - - - - - - -
ALD2 44.05 12 2 - - - - - - - - - -
ALK4 58.12 12 4 - - - - - - - - - -
ASOAN
ASOA1
ASOA2
ASOA3
150 150 - NO 0.8 1.0 0.5 1.0 0.8 0.0 0.8 - -
ASOG1
ASOG2
ASOG3
150 150 - - - - - - - - - 2.0e-2 -
Be7 201 201 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
Br2 160 160 - - - - - - - - - 0.0 -
BCPI 12.01 12 1 NO 1.0 1.0 1.0 0.5 1.0 0.0 1.0 - -
BCPO 12.01 12 1 NO 1.0 1.0 1.0 0.5 1.0 1.0 0.0 - -
CH2O 30 30 - - - - - - - - - 2.0e-2 Jacob et al [2000]
DST1
DSTAL1
NITD1
SO4D1
29 29 - NO 1.0 1.0 1.0 1.0 1.0 1.0 1.0 - -
DST2
DSTAL2
NITD2
SO4D2
29 29 - YES 1.0 1.0 1.0 1.0 1.0 1.0 1.0 - -
DST3
DSTAL3
NITD3
SO4D3
29 29 - YES 1.0 1.0 1.0 1.0 1.0 1.0 1.0 - -
DST4
DSTAL4
NITD4
SO4D4
29 29 - YES 1.0 1.0 1.0 1.0 1.0 1.0 1.0 - -
GLYC 60 60 - - - - - - - - - 2.0e-2 -
GLYX 58 58 - - - - - - - - - - -
H2O2 34 34 - - - - - - - - - 5.00e-2 Jacob et al [2000]
HAC 74 74 - - - - - - - - - - -
HBr 81 81 - - - - - - - - - 1.0 -
HCl 36 36 - - - - - - - - - 1.0 -
Hg2 201 201 - - - - - - - - - 0.0 -
HgP 201 201 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
HNO3 63 63 - - - - - - - - - - -
HOBr 97 97 - - - - - - - - - 0.0 -
IEPOX 118 118 - - - - - - - - - 2.0e-2 -
ISOA1
ISOA2
ISOA3
150 150 - NO 0.8 1.0 0.5 1.0 0.8 0.0 0.8 - -
ISOG1
ISOG2
ISOG3
150 150 - - - - - - - - - 2.0e-2 -
ISOPN 147 147 - - - - - - - - - 2.0e-2 -
LIMO
MTPA
MTPO
136.23 136.23 - - - - - - - - - 2.0e-2 -
MAP 76 76 - - - - - - - - - 2.0e-2 -
MMN 149 149 - - - - - - - - - 2.0e-2 -
MOBA 114 114 - - - - - - - - - 2.0e-2 -
MOPI 12.01 12 1 NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
MOPO 12.01 12 1 NO 0.0 1.0 1.0 1.0 0.0 0.0 0.0 - -
MSA 96 96 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
NH3 17 17 - - - - - - - - - 5.0e-2 Jacob et al [2000]?
NH4 18 18 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
NIT 62 62 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
NITs 31.4 31.4 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
OCPI
POA1
12.01 12 1 NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
OCPO
POA2
12.01 12 1 NO 1.0 0.5 0.5 0.5 1.0 0.0 1.0 - -
OPOA1
OPOA2
12.01 12 1 NO 0.8 1.0 0.5 1.0 0.8 0.0 0.8 - -
OPOG1
OPOG2
12.01 12 1 - - - - - - - - 2.0e-2 -
Pb210 210 210 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
POG1
POG2
12.01 12 1 - - - - - - - - 2.0e-2 -
POPPBCPI
(PHE)
178.23 178.23 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
POPPBCPI
(PYR)
202.25 202.25 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
POPPBCPI
(BaP)
252.31 252.31 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
POPPBCPO
(PHE)
178.23 178.23 - NO 1.0 1.0 1.0 0.5 1.0 1.0 0.0 - -
POPPBCPO
(PYR)
202.25 202.25 - NO 1.0 1.0 1.0 0.5 1.0 1.0 0.0 - -
POPPBCPO
(BaP)
252.31 252.31 - NO 1.0 1.0 1.0 0.5 1.0 1.0 0.0 - -
POPPOCPI
(PHE)
178.23 178.23 - NO 1.0 1.0 0.5 1.0 1.0 1.0 1.0 - -
POPPOCPI
(PHE)
202.25 202.25 - NO 1.0 1.0 0.5 1.0 1.0 1.0 1.0 - -
POPPOCPI (PHE) 252.31 252.31 - NO 1.0 1.0 0.5 1.0 1.0 1.0 1.0 - -
POPOCPO
(PHE)
178.23 178.23 - NO 1.0 1.0 1.0 0.5 1.0 1.0 0.0 - -
POPOCPO
(PYR)
202.25 202.25 - NO 1.0 1.0 1.0 0.5 1.0 1.0 0.0 - -
POPOCPO
(BaP)
252.31 252.31 - NO 1.0 1.0 1.0 0.5 1.0 1.0 0.0 - -
POPG (PHE) 178 178 - - - - - - - - - 0.0 -
POPG (PYR) 202 178 - - - - - - - - - 0.0 -
POPG (BaP) 252 178 - - - - - - - - - 0.0 -
PROPNN 119 119 - - - - - - - - - 2.0e-2 -
RIP 118 118 - - - - - - - - - 2.0e-2 -
SALA 31.4 31.4 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
SALC 31.4 31.4 - YES 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
SO2 64 64 - - - - - - - - - - -
SO4 96 96 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
SO4s 31.4 31.4 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
TSOA0
TSOA1
TSOA2
TSOA3
150 150 - NO 0.8 1.0 0.5 1.0 0.8 0.0 0.8 - -
TSOG0
TSOG1
TSOG2
TSOG3
150 150 - - - - - - - - - 2.0e-2 -
TOMAS microphysics species Aerosol Species Parameters Gas-phase Species Parameters
DUST1-
DUST40
100 100 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
ECIL1-
ECIL40
96 96 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
NK1-NK40 1 1 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
OCIL1-
OCIL40
12 12 1 NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
SF1-
SF40
96 96 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -
SS1-
SS40
58.5 58.5 - NO 1.0 1.0 0.5 1.0 1.0 0.0 1.0 - -

NOTES:

  1. We follow the algorithm of Qiaoqiao Wang et al (2014) for scavenging by snow and impaction scavenging for BC and IN, namely:
    • When 237 K <= T < 258 K:
      • Multiply Kc—the rate at which cloud condensate changes into precipitation— by 0.5, and
      • Allow black carbon, dust, HNO3, 210Pb, and 7Bethe following species, which are considered to be IN, to be rained out (aka "cold cloud scavenging").
      • Do not allow any other soluble aerosol species to rain out (i.e. set the rainout fraction to zero).

--Bob Y. (talk) 20:34, 23 October 2015 (UTC)

Discrepancies found in the wet deposition module

During the implementation of the species database of physical properties into GEOS-Chem, we discovered a few issues with how species were defined in the wet deposition module wetscav_mod.F. Some of these errors are typos, others (we think) are historical baggage.

Species Issue Solution Status
MOBA
  • Routines COMPUTE_F and RAINOUT use the Henry's law parameter K0 = 2.3e+4.
  • But routine WASHOUT uses the Henry's law parameter K0 = 2.6e+4.
  • This appears to be a typo.
  • Use the value K0 = 2.3e+4 for MOBA everywhere in GEOS-Chem.

--Bob Yantosca (talk) 17:12, 22 February 2016 (UTC)

POPs parameters

The persistent organic pollutants (POPs) species have special parameters:

Species Mol. Wt.
[g mol-1]
KOA KBC POPG_OH POPG_O3A POPG_O3B HSTAR DEL_H DEL_Hw
POPG (PHE) 178.23 4.37e+07 1.0e+10 2.7e-11 0.0 2.15e+15 1.74e-03 -7400 47
POPG (PYR) 202.25 7.24e+08 1.0e+11 50.0e-12 0.0 3.0e+15 5.37e-04 -8700 43
POPG (BaP) 252.31 3.02e+11 7.94e+13 50.0e-12 0.0 2.8e+15 3.10e-05 -11000 43

References

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  2. Betterton, E. A. and Hoffmann, M. R.: Henry’s law constants of some environmentally important aldehydes, Environ. Sci. Technol., 22, 1415–1418, 1988.
  3. Chameides, W. L.: Reply, J. Geophys. Res., 91D, 14571–14572, 1986.
  4. Dean, J. A.: Lange’s Handbook of Chemistry, McGraw-Hill, Inc., 1992.
  5. Fried, A., Henry, B. E., Calvert, J. G., and Mozurkewich, M.: The reaction probability of N2O5 with sulfuric acid aerosols at stratospheric temperatures and compositions, J. Geophys. Res., 99D, 3517–3532, 1994.
  6. Ji, C. and Evans, E. M.: Using an internal standard method to determine Henry’s law constants, Environ. Toxicol. Chem., 26, 231–236, 2007.
  7. Kames, J. and Schurath, U.: Henry’s law and hydrolysis-rate constants for peroxyacyl nitrates (PANs) using a homogeneous gasphase source, J. Atmos. Chem., 21, 151–164, 1995.
  8. Lee, Y.-N. and Zhou, X.: Method for the determination of some soluble atmospheric carbonyl compounds, Environ. Sci. Technol., 27, 749–756, 1993.
  9. Lelieveld, J. and Crutzen, P. J.: The role of clouds in tropospheric photochemistry, J. Atmos. Chem., 12, 229–267, 1991.
  10. Leng, C., Kish, J. D., Kelley, J., Mach, M., Hiltner, J., Zhang, Y., and Liu, Y.: Temperature-dependent Henry’s law constants of atmospheric organics of biogenic origin, J. Phys. Chem. A, 117, 10359–10367, 2013.
  11. Leu, M.-T. and Zhang, R.: Solubilities of CH3C(O)OO2NO2 and HO2NO2 in water and liquid H2SO4, Geophys. Res. Lett., 26, 1129–1132, 1999.
  12. Mozurkewich, M.: Mechanisms for the release of halogens from sea-salt particles by free radical reactions, J. Geophys. Res., 100D, 14 199–14 207, 1995.
  13. Sander, S. P., Abbatt, J., Barker, J. R., Burkholder, J. B., Friedl, R. R., Golden, D. M., Huie, R. E., Kolb, C. E., Kurylo, M. J., Moortgat, G. K., Orkin, V. L., and Wine, P. H.: Chemical Kinetics and Photochemical Data for Use in Atmospheric Studies, Evaluation No. 17, JPL Publication 10-6, Jet Propulsion Laboratory, Pasadena, available at: http://jpldataeval.jpl.nasa.gov (last access: 10 April 2015), 2011.
  14. Sander, R., Compilation of Henry's law constants (version 4.0) for water as solvent, Atmos. Chem. Phys, 15, 4399-4981, 2015. (Download from http://henrys-law.org]
  15. Schwartz, S. E. and White, W. H.: Solubility equilibria of the nitrogen oxides and oxyacids in dilute aqueous solution, in: Advances in Environmental Science and Engineering, edited by: Pfafflin, J. R. and Ziegler, E. N., Gordon and Breach Science Publishers, NY, vol. 4, 1–45, 1981.
  16. Warneck, P. and Williams, J.: The Atmospheric Chemist’s Companion: Numerical Data for Use in the Atmospheric Sciences, Springer Verlag, 2012.
  17. Zhou, X. and Mopper, K.: Apparent partition coefficients of 15 carbonyl compounds between air and seawater and between air and freshwater; Implications for air-sea exchange, Environ. Sci. Technol., 24, 1864–1869, 1990.

--Bob Y. (talk) 16:13, 18 August 2015 (UTC)