부산대학교 도서관

Measurements of total peroxy radicals (HO + RO) and nitrate radical (NO) were made on the NOAA research vessel R/V Brown along the U.S. Gulf Coast during the TexAQS 2006 field campaign. The measurements were modelled using a constrained box-model based upon the Master Chemical Mechanism (MCM). The agreement between modelled and measured HO + RO was typically within ∼40% and, in the unpolluted regions, within 30%. The analysis of the model results suggests that the MCM might underestimate the concentrations of some acyl peroxy radicals and other small peroxy radicals. The model underestimated the measurements of NO by 60-70%, possibly because of rapid heterogeneous uptake of NO. The MCM model results were used to estimate the composition of the peroxy radical pool and to quantify the role of DMS, isoprene and alkenes in the formation of RO in the different regions. The measurements of HO + RO and NO were also used to calculate the gas-phase budget of NO and quantify the importance of organic peroxy radicals as NO sinks. RO accounted, on average, for 12-28% of the total gas-phase NO losses in the unpolluted regions and for 1-2% of the total gas-phase NO losses in the polluted regions. [ABSTRACT FROM AUTHOR]