The Lagrangian ozone model: Chemical reactions

Reaction coefficients are in units of s^-1 for unimolecular reactions, cm³ molecule^-1 s^-1 for bimolecular reactions, and cm⁶ molecule^-2 s^-2 for termolecular reactions. Reaction steps labelled as "Immediate" are given for clarity only.

**Table 1.2:** Photo-oxidant Chemistry: Lagrangian Model
Rate coefficient	Reaction

Notes:
"t" is temperature, M is third body.

Generic reaction rates

FHO2=(1.+1.4E-21H2Oexp(2200./t))
KRO2NO=4.2E-12*exp(180./t)
KHO2RO2=1.0E-11
KRC87=1.0E-12*exp(190./t)
KRC91=5.8E-12*exp(190./t)
KRC92=1.9E-12*exp(190./t)


Inorganic chemistry

5.7E-34*(t/300.0)^-2.8	O+O2+M $\rightarrow$ O3
9.6E-32*(t/300.0)^-1.6	O+NO+M $\rightarrow$ NO2
2.0E-11*exp(100.0/t)	OD+M $\rightarrow$ O
2.2E-10	OD+H2O $\rightarrow$ OH+OH
Immediate	H+O2 $\rightarrow$ HO2
1.8E-12*exp(-1370./t)	O3+NO $\rightarrow$ NO2
1.2E-13*exp(-2450./t)	O3+NO2 $\rightarrow$ NO3
1.9E-12*exp(-1000./t)	O3+OH $\rightarrow$ HO2
1.4E-14*exp(-600./t)	O3+HO2 $\rightarrow$ OH
1.8E-11*exp(110./t)	NO+NO3 $\rightarrow$ NO2+NO2
3.7E-12*exp(240./t)	NO+HO2 $\rightarrow$ NO2+OH
7.2E-14*exp(-1414./t)	NO2+NO3 $\rightarrow$ NO+NO2
1.4E-12	NO2+NO3 $\rightarrow$ N2O5
1.4E-11	NO2+OH $\rightarrow$ HNO3
4.1E-16	NO3+H2O2 $\rightarrow$ HO2+HNO3
7.1E+14*exp(-11080./t)	N2O5 $\rightarrow$ NO2+NO3
4.8E-11*exp(250./t)	OH+HO2 $\rightarrow$ H2O
2.9E-12*exp(-160./t)	OH+H2O2 $\rightarrow$ HO2
7.7E-12*exp(-2100./t)	OH+H2 $\rightarrow$ H
1.0E-14*exp(785./t)	OH+HNO3 $\rightarrow$ NO3
FHO22.3E-13exp(600./t)	HO2+HO2 $\rightarrow$ H2O2
FHO2M1.7E-33*exp(1000./t)	HO2+HO2 $\rightarrow$ H2O2

Sulphur chemistry

1.35E-12	OH+SO2 $\rightarrow$ HSO3
4.0E-17	CH3O2+SO2 $\rightarrow$ SO3+CH3O
Immediate	HSO3+O2 $\rightarrow$ HO2+SO3
Immediate	SO3+H2O $\rightarrow$ SA

Methane chemistry

7.4410^-18 x T² x exp*(-1361/T)	OH+CH4 $\rightarrow$ CH3
Immediate	CH3+O2 $\rightarrow$ CH3O2
KRO2NO	CH3O2+NO $\rightarrow$ CH3O+NO2
5.5E-14*exp(365./t)	CH3O2+CH3O2 $\rightarrow$ CH3O+CH3O
5.5E-14*exp(365./t)	CH3O2+CH3O2 $\rightarrow$ CH3OH+HCHO
3.3E-12*exp(-380./t)	OH+CH3OH $\rightarrow$ HO2+HCHO
3.8E-13*exp(780./t)	HO2+CH3O2 $\rightarrow$ CH3O2H
Immediate	CH3O+O2 $\rightarrow$ HCHO+HO2
9.6E-12	OH+HCHO $\rightarrow$ HCO
Immediate	HCO+O2 $\rightarrow$ CO+HO2
1.0E-12*exp(190./t)	CH3O2H + OH $\rightarrow$ HCHO + OH
1.9E-12*exp(190./t)	CH3O2H + OH $\rightarrow$ CH3O2
5.8E-16	NO3+HCHO $\rightarrow$ HNO3+HCO
2.4E-13	OH+CO $\rightarrow$ H

Ethane chemistry

7.8E-12*exp(-1020./t)	OH+C2H6 $\rightarrow$ C2H5O2
8.9E-12	C2H5O2+NO $\rightarrow$ C2H5O+NO2
6.5E-13*exp(650./t)	C2H5O2+HO2 $\rightarrow$ C2H5OOH
5.8E-12*exp(190./t)	C2H5OOH+OH $\rightarrow$ CH3CHO+OH
1.9E-12*exp(190./t)	C2H5OOH+OH $\rightarrow$ C2H5O2
Immediate	C2H5O+O2 $\rightarrow$ HO2+CH3CHO
5.6E-12*exp(310./t)	OH+CH3CHO $\rightarrow$ CH3COO2
1.0E-11	CH3COO2+NO2 $\rightarrow$ PAN
1.34E+16*exp(-13330./t)	PAN $\rightarrow$ CH3COO2+NO2
2.0E-11	CH3COO2+NO $\rightarrow$ NO2+CH3
5.5E-12	CH3O2+CH3COO2 $\rightarrow$ CH3O+CH3
5.5E-12	CH3O2+CH3COO2 $\rightarrow$ CH3COOH+HCHO
2.8E-12*exp(530/t)	CH3COO2+CH3COO2 $\rightarrow$ CH3+CH3
1.3E-13*exp(1040./t)	CH3COO2+HO2 $\rightarrow$ CH3COO2H
1.9E-12*exp(190./t)	CH3COO2H+OH $\rightarrow$ CH3COO2
3.0E-13*exp(1040./t)	CH3COO2+HO2 $\rightarrow$ CH3COOH + O3

Ethanol chemistry

3.2E-12	OH+C2H5OH $\rightarrow$ CH3CHO + HO2

n-butane chemistry

1.64E-11*exp(-559./t)	OH+NC4H10 $\rightarrow$ SECC4H9O2
KRO2NO	NO+SECC4H9O2 $\rightarrow$ NO2+SECC4H9O
Immediate	SECC4H9O $\rightarrow$ 0.65 HO2 + 0.65 CH3COC2H5 + 0.35 CH3CHO +0.35 C2H5O2
1.15E-12	OH+CH3COC2H5 $\rightarrow$ CH3COCHO2CH3
KRO2NO	CH3COCHO2CH3+NO $\rightarrow$ NO2+CH3COO2+CH3CHO
KHO2RO2	CH3COCHO2CH3+HO2 $\rightarrow$ CH3COCHO2HCH3
4.8E-12	CH3COCHO2HCH3+OH $\rightarrow$ CH3COCHO2CH3
KHO2RO2	SECC4H9O2+HO2 $\rightarrow$ SECC4H9O2H
KRC92	SECC4H9O2H+OH $\rightarrow$ SECC4H9O2
KRC91	SECC4H9O2H+OH $\rightarrow$ OH+CH3COC2H5

Ethene chemistry

1.66E-12*exp(474./t)	C2H4+OH $\rightarrow$ CH2O2CH2OH
KRO2NO	CH2O2CH2OH+NO $\rightarrow$ NO2+HCHO+HCHO+HO2
KHO2RO2	CH2O2CH2OH+HO2 $\rightarrow$ CH2OOHCH2OH
KRC91	CH2OOHCH2OH+OH $\rightarrow$ CH3CHO + OH
KRC92	CH2OOHCH2OH+OH $\rightarrow$ CH2O2CH2OH
1.2E-14*exp(-2630./t)	C2H4+O3 $\rightarrow$ HCHO+0.44 CO+ 0.12 HO2+ 0.4 HCOOH+ 0.13 H2

Propene chemistry

6.5E-15*exp(-1880./t)	O3+C3H6 $\rightarrow$ 0.5 HCHO+ 0.5 CH3CHO+ 0.07 CH4+ 0.4 CO+ 0.28 HO2+ 0.15 OH+ 0.31 CH3O2+ 0.07 H2
2.86E-11	OH+C3H6 $\rightarrow$ CH3CHO2CH2OH
KRO2NO	NO+CH3CHO2CH2OH $\rightarrow$ NO2+CH3CHO+HCHO+HO2
KHO2RO2	CH3CHO2CH2OH+HO2 $\rightarrow$ CH3CHOOHCH2OH
KRC91	CH3CHOOHCH2OH+OH $\rightarrow$ CH3COC2H5+OH
KRC92	CH3CHOOHCH2OH+OH $\rightarrow$ CH3CHO2CH2OH



o-xylene chemistry

1.37E-11	OXYL+OH $\rightarrow$ OXYO2
KRO2NO	OXYO2+NO $\rightarrow$ NO2+MGLYOX+MAL+HO2
KHO2RO2	OXYO2 + HO2 $\rightarrow$ OXYO2H
1.7E-11	OXYO2H + OH $\rightarrow$ OXYO2
2.0E-11	MAL+OH $\rightarrow$ MALO2
KRO2NO	MALO2+NO $\rightarrow$ NO2+HO2+MGLYOX+GLYOX
KHO2RO2	MALO2+HO2 $\rightarrow$ MALO2H
2.4E-11	MALO2H+OH $\rightarrow$ MALO2
1.1E-11	OH+GLYOX $\rightarrow$ HO2+CO+CO
1.70E-11	OH+MGLYOX $\rightarrow$ CH3COO2+CO

Aerosol chemistry

RH dependent	H2O2 $\rightarrow$ aerosol
RH dependent	CH3O2H $\rightarrow$ aerosol
RH dependent	N2O5 $\rightarrow$ 2 x nitrate
RH dependent	HNO3 $\rightarrow$ nitrate

Isoprene chemistry

12.3E-15*exp(-2013/t)	ISOP+O3 $\rightarrow$ 0.67 MACR, 0.26 MVK+0.3 O, 0.55 OH+0.07 C3H6+0.8 HCHO+0.06 HO2+0.05 CO
2.54E-11*exp(410./t)	ISOP+OH $\rightarrow$ ISRO2
KRO2NO	ISRO2+NO $\rightarrow$ 0.32 MACR+0.42 MVK+0.74 HCHO, 0.14 ISNI+0.12 ISRO2+0.78 HO2+0.86 NO2
4.13E-12*exp(452./t)	MVK+OH $\rightarrow$ MVKO2

KRO2NO	MVKO2+NO $\rightarrow$ 0.684 CH3CHO+0.684 CH3COO2+ 0.266 MGLYOX+0.266 HCHO+0.05 ISNI+0.95 NO2+0.95 HO2
KHO2RO2	ISRO2+HO2 $\rightarrow$ ISRO2H
2.0E-11	ISRO2H + OH $\rightarrow$ OH+ISRO2
8.0E-18	ISRO2H + O3 $\rightarrow$ *0.7:HCHO
1.86E-11*exp(175./t)	MACR+OH $\rightarrow$ 0.5 AOH1+ 0.5:MACRO2
1.0E-11	MACRO2+NO2 $\rightarrow$ MPAN
1.34E+16*exp(-13330./t)	MPAN $\rightarrow$ MACRO2+NO2
2.0E-11	MACRO2+NO $\rightarrow$ CH2CCH3+NO2
KRO2NO	CH2CCH3+NO $\rightarrow$ NO2+CH3COC2H5+HO2
4.32E-15*exp(-2016./t)	MVK+O3 $\rightarrow$ 0.82 MGLYOX+0.8 HCHO+0.2 O+ 0.05 CO+0.06 HO2+0.04 CH3CHO+0.08 OH
3.35E-11	ISNI+OH $\rightarrow$ ISNIR
KRO2NO	ISNIR+NO $\rightarrow$ 0.05 HO2+ 2.0 NO2+ 0.95 CH3CHO+ 0.95 CH3COC2H5

NO3 chemistry
7.8E-13	ISOP +NO3 $\rightarrow$ ISONO3
KRO2NO	ISONO3+NO $\rightarrow$ 1.1 NO2+0.8 HO2+0.85 ISNI+0.1 MACR+0.15 HCHO+0.05 MVK

Extra since Note 2/93 (Simpson et al. 1993)

KHO2RO2	MVKO2 + HO2 $\rightarrow$ MVKO2H
KHO2RO2	MACRO2 + HO2 $\rightarrow$ MARO2H
KHO2RO2	CH2CCH3+ HO2 $\rightarrow$ CH2CO2HCH3
KHO2RO2	ISNIR + HO2 $\rightarrow$ ISNIRH
KHO2RO2	ISONO3 + HO2 $\rightarrow$ ISONO3H
3.2E-11	CH2CO2HCH3 + OH $\rightarrow$ CH2CCH3
2.0E-11	ISONO3H + OH $\rightarrow$ ISONO3
2.2E-11	MVKO2H + OH $\rightarrow$ MVKO2
3.7E-11	ISNIRH + OH $\rightarrow$ ISNIR
3.7E-11	MARO2H + OH $\rightarrow$ MACRO2

OXYO2	Peroxy radical from o-xylene + OH
OXYO2H	Hydroperoxide from OXYO2 + HO2
GLYOX	Glyoxal (HCOCHO)
MGLYOX	Methyl-glyoxal (CH3COCHO)
MAL	CH₃COCH=CHCHO
MALO2	Peroxy radical from MAL + OH
MALO2H	Hydroperoxide from MALO2 + HO2
ISRO2	Peroxy radical from isoprene + OH
ISRO2H	Hydroperoxide from ISRO2 + HO2
MACR	Methacrolein
MACRO2	Hydroperoxide from Methacrolein
MPAN	Peroxy methacryloyl nitrate (CH₂CH(CH₃)C(=O)O₂NO₂)
MVK	Methyl-vinyl-ketone
MVKO2	Peroxy radical from MVK + OH
MVKO2H	Hydroperoxide from MVKO2 + HO₂
ISNI	Organic nitrate from isoprene
ISONO3	Isoprene-NO₃ adduct
ISNIR	Alkyl peroxy radical from ISNI