Coastal Marine Boundary Layer Oxidants and 13C and 14C in HCHO and CH3CHO

The goal of the project is to provide constraints on photochemical oxidants, volatile organic compound (VOC) emission inventories at regional scales, and on chemical mechanisms of VOC and oxygenated VOC (OVOC) oxidation by mean measurements of hydroperoxides and formaldehyde. Hydrogen peroxide (HP), methyl hydroperoxide (MHP), peroxyacetic acid (PAA), formaldehyde (FO), acetaldehyde (AC) and acetone (ACO) are the foci of this work. Their distributions in the atmosphere reflect an integral of OVOC and VOC emissions, chemistry and transport, and their corresponding effects on tropospheric ozone, hydroxyl radical concentrations, and particulate matter. The overarching scientific objectives are to: �?� Determine the distribution of the target compounds in the �??pristine�?� and polluted (urban and ship impacted) sub-tropical and mid-latitude marine environment off the coast of California, �?� Quantify the relative importance of biogenic vs. anthropogenic VOCs and OVOCs to the regional polluted coastal atmosphere, and �?� Determine how well those emissions and the subsequent photochemical pathways are represented in current-generation chemical transport models (CTMs)