Effect of marine and land convection on wet scavenging of ozone precursors observed during a SEAC4RS case study

The SEs of 44%-53% for CH2O and 85%-90% for H2O2 are consistent with our previous studies from SEAC(4)RS and the 2012 DC3 field experiment storms. Using WRF-Chem simulations, the ice retention factor (r(f)) for CH2O was determined to be 0.5-0.9, which is higher than found in previous studies. We show that the CH2O r(f) is higher in airmass and multicell storms than in severe storms and hypothesize that ice shattering may affect CH2O r(f) values.

The CH3OOH SEs (39%-73%) were higher than expected from Henry's Law equilibrium. While recent studies suggest that CH3OOH measurements have interference due to methane diol, we find that this interference cannot fully explain the higher-than-expected CH3OOH SEs determined here and during DC3, suggesting further research is needed to understand CH3OOH vertical redistribution.