Collaborative Research: Formation of Organic Nitrogen and Secondary Organic Aerosol Related to Nitrate Radical Oxidation of Volatile Organic Compounds

William Marsh Rice University, Houston TX

Investigators

Abstract

This project focuses on increasing the understanding of how human-produced emissions combine with biogenic emissions from forests to influence the formation of small particles in the atmosphere. A mobile laboratory will be deployed to two different types of forests (urban and remote) in order to compare and contrast the impact of long-range and short-range transport of nitrogen species to forests. The results will lead to improved control strategies that minimize the health, visibility and climate effects of anthropogenic emissions. The primary objectives of the science campaign are to: (1) Characterize the ambient aerosol, radiation, and trace gases at two forest sites, both above and below the canopy, and along a north-south transect in the central United States; (2) Quantify the level of oxidation found in SOA using atomic ratios (such as the oxygen to carbon ratio, O:C) and determine the impact the presence of particulate organic nitrate (PON) has on the observed oxidation state of the submicron particulate matter (PM); (3) Investigate how in-canopy gradients and through-canopy transport impact submicron PM, PON, and oxidants; (4) Determine the impact nitrogen oxides (NOx) have on volatile organic carbon (VOC) oxidation and SOA formation in all locations; (5) Compare and contrast the chemistry of remote, on-road, and urban forested areas; (6) Identify the factors contributing to SOA using positive matrix factorization (PMF) to identify important components of SOA under different levels of anthropogenic influence both above and below canopy; and (7) Investigate the fate of NOx in all locations.