Figure 4.25 shows the absorption cross sections for H202 and methyl hydroperoxide at room temperature, and Table 4.23 summarizes these data (Vaghjiani and Ravishankara, 1989; DeMore et al., 1997). Although the absorption is dropping off rapidly at wavelengths above the actinic cutoff of 290 nm, photolysis is still a significant loss process for these peroxides in the troposphere. In both cases, OH is the major product formed, with a product quantum yield of 2 for H202, corresponding to a photodissociation quantum yield of f at wavelengths > 222 nm (e.g., Vaghjiani and Ravishankara, 1990; Vaghjiani et al., 1992),
and a quantum yield of f at 248 nm for CH3OOH (Vaghjiani and Ravishankara, 1990; Thelen et al., 1993)
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