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Photolysis Parameters

NOTE: Photolysis rate parameterisations calculated using these new recommended cross section (CS) and quantum yields (QYs), which enable the quick running of MCMv3.2 models, will be available soon.
The MCMv3.1 parameterisations are still available on the MCMv3.1 archive site (click here)
Reactant^‡	MCMv3.2 designation^a	Products	Absorption Cross-section (ς)^§	Quantum Yield (φ)^§	Comments
Inorganics
O3	(J₁) (J₂)	→ O(¹D) +O₂ → O(³P) +O₂	Molina and Molina (1986) link	Matsumi et al. (2002) link Matsumi et al. (2002) link IUPAC recommended	T dependent CS defined. 298 K QYs defined. T dependent (O¹D) QY calculation available here.
H2O2	(J₃)	→ OH + OH	Average from: Lin et al. (1978) link Molina and Molina (1981) link Nicovich and Wine (1988) link Vaghjiani & Ravishankara (1989) link IUPAC recommended	Vaghjiani & Ravishankara (1990) link IUPAC recommended	QY (J₃) 1.00 (> 230 nm)
NO2	(J₄)	→ NO + O(³P)	Average from: Merienne et al. (1995) link Coquart et al. (1995) link Jenouvrier et al. (1996) link Merienne et al. (1997) link IUPAC recommended	Gardner et al. (1987) link IUPAC recommended	QY corrected by Troe et al. (2000) link
NO3	(J₅) (J₆)	→ NO + O₂ → NO₂ + O(³P)	Sander (1986) link IUPAC recommended	Johnston et al. (1996) link Johnston et al. (1996) link IUPAC recommended	QY (J₆) is 1.00 below 585 nm
HONO	(J₇)	→ NO + OH	Bongartz et al. (1991, 1994) link link IUPAC recommended	Cox and Derwent (1976-77) link IUPAC recommended	QY (J₇) is 1.00 (190 to 400 nm)
HNO3	(J₈)	→ NO₂ + OH	Burkholder et al. (1993) IUPAC recommended	Turnipseed et al. (1991) link IUPAC recommended	T dependent CS defined. QY (J₈) is 1.00 (> 248 nm)
Carbonyls
HCHO	(J₁₁) (J₁₂)	→ H + HCO → H₂ + CO	Meller and Moortgat (2000) link IUPAC recommended	(J₁₁) Smith et al. (2002) link (J₁₂) Moortgat et al. (1983) link IUPAC recommended	Temperature dependent CS. (J₁₂) QYs are p and T dependent > 330 nm.
CH3CHO	(J₁₃)	→ CH₃ + HCO	Martinez et al. (1992) link IUPAC recommended	Meyrahn et al. (1982) IUPAC recommended	Only the radical channel (J₁₃) is important > 290 nm.
C2H5CHO	(J₁₄)	→ C₂H₅ + HCO	Martinez et al. (1992) link IUPAC recommended	Chen and Zhu (2001) link IUPAC recommended	(J₁₄) p dependent QYs calculation available here. IUPAC discusses QY but cannot recommend values.
C3H7CHO	(J₁₅)^b (J₁₆)	→ n-C₃H₇ + HCO → C₂H₄ + CH₃CHO	Martinez et al. (1992) link IUPAC recommended	(J₁₅) Tadic et al. (2001) link (J₁₆) Tadic et al. (2001) link IUPAC recommended	QY (J₁₅) 0.21 (290 to 380 nm) QY (J₁₆) 0.10 (290 to 380 nm)
IPRCHO	(J₁₇)^b	→ n-C₄H₉ + HCO	Martinez et al. (1992) link	Chen et al. (2002) link
MACR	(J₁₈)^b (J₁₉)^b	→ CH₂=CCH₃ + HCO → CH₂=C(CH₃)CO + H	Gierczak et al. (1997) link IUPAC recommended	Average from: Carter (2000) Moortgat et al. (2000) Pinho et al. (2005) link IUPAC recommended	QY (J₁₈) 1.95E-3 QY (J₁₉) 1.95E-3 See Pinho et al. (2005) link for details
CH3COCH3	(J₂₁)	→ CH₃CO + CH₃	Gierczak et al. (1998) link IUPAC recommended	Blitz et al. (2004) link IUPAC recommended	T dependent CS defined. 298 K CS available here(calculation here). 1 bar and 298 K QY defined. T and p dependent QY calculation available here. Only channel (J₂₁) currently defined in MCMv3.2.
MEK	(J₂₂)^b	→ CH₃CO + C₂H₅	Martinez et al. (1992) link IUPAC recommended	Pinho et al. (2005) link	QY (J₂₂) 0.16 (275 to 380 nm) 298 K CS available here(calculation here). Average of the optimised QY used in the evaluation of the MCM and SAPRC-99 using chamber data (see Pinho et al. (2005) link for details)
MVK	(J₂₃) (J₂₄)^b	→ CH₃CH=CH₂ + CO → CH₃CO + CH₂=CH	Gierczak et al. (1997) link IUPAC recommended	Gierczak et al. (1997) link IUPAC recommended	Atmospheric pressure QYs defined (1 bar). p dependent QY calculation available here.
GLYOX	(J₃₁) (J₃₂) (J₃₃)	→ CO + CO + H₂ → HCHO + CO → HCO + HCO	Volkamer et al. (2005) link	Tadic et al. (2006) link	Recommended CS are within in 5 % of the IUPAC recommended CS of Horowitz et al. (2001) link.
MGLYOX	(J₃₄)^b	→ CH₃CO + HCO	Combination of: Staffelbach et al. (1995) link Meller et al. (1991) link IUPAC recommended	Chen et al. (2000) link IUPAC recommended	p dependent QY calculation available here. Zero and 760 Torr QY data in reasonable agreement with Koch and Moortgat (1998) link.
BIACET	(J₃₅)^b	→ CH₃CO + CH₃CO	Horowitz et al. (2001) link	Plum et al. (1983) link	QY (J₃₅) 0.158 (290 to 460 nm)
Organic Peroxides
CH3OOH	(J₄₁)^b	→ CH₃O + OH	Vaghjiani & Ravishankara (1989) link IUPAC recommended	Vaghjiani & Ravishankara (1990) link IUPAC recommended	QY (J₄₁) 1.00 (> 290 nm)
Organic Nitrates
CH3NO3	(J₅₁)	→ CH₃O + NO₂	Average from: Roberts and Fajer (1989) link Rattigan et al. (1992) link Talukdar et al. (1997) link IUPAC recommended	Talukdar et al. (1997) link IUPAC recommended	T dependent CS defined QY (J₅₁) 1.00 (> 248 nm)
C2H5NO3	(J₅₂)	→ C₂H₅O + NO₂	Average from: Zhu and Ding (1997) link Clemitshaw et al. (1997) link Talukdar et al. (1997) link Turberg et al. (1990) link IUPAC recommended	Zhu and Ding (1997) link IUPAC recommended	298 K CS taken from Turberg et al. (1990) link T dependent average defined QY (J₅₂) 1.00 (290 to 340 nm)
NC3H7NO3	(J₅₃)^b	→ n-C₃H₇O + NO₂	Average from: Roberts and Fajer (1989) link Turberg et al. (1990) link Clemitshaw et al. (1997) link Talukdar et al. (1997) link IUPAC recommended	φ = 1.00 IUPAC recommended	No data on either the photo-products or the quantum yields. QY based on data for ethyl and methyl nitrate (see IUPAC recommendations).
IC3H7NO3	(J₅₄)^b	→ CH₃C(O.)CH₃ + NO₂	Average from: Roberts and Fajer (1989) link Turberg et al. (1990) link Clemitshaw et al. (1997) link Talukdar et al. (1997) link IUPAC recommended	φ = 1.00 IUPAC recommended	T dependent CS defined. No data on either the photo-products or the quantum yields. QY based on data for ethyl and methyl nitrate (see IUPAC recommendations).
TC4H9NO3	(J₅₅)^b	→ t-C₄H₉O + NO₂	Roberts and Fajer (1989) link	φ = 1.00	298 K CS wavelength dependent parameterisation available. QY assumed to be unity.
NOA	(J₅₆)^b (J₅₇)^b	→ CH₃C(O)CH₂(O.) + NO₂ → CH₃CO + HCHO + NO₂	Average from: Roberts and Fajer (1989) link Barnes et al. (1993) link	Estimated	298 K CS wavelength dependent parameterisations available. QY estimated by analogy to the photolysis of ethyl nitrate and acetone (see Jenkin et al. (1997) link).