Sources and fate of atmospheric organic nitrogen

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Organic compounds can be released to the atmosphere through human activities or biological processes. These chemicals can be present in the gas or particle phase and can have important effects on the atmospheric and terrestrial environment, including climate and human health. In particular, organic compounds containing nitrogen can contribute to particle formation and act as a nitrogen input to nutrient-depleted areas. The role of organic nitrogen compounds in atmospheric processes is an emerging area of study and is poorly described. We will examine the sources and fate of organic nitrogen compounds through a combination of laboratory experiments and environmental sample analysis.A major source of nitrogenous organic compounds to the atmosphere is the ocean. Through wave action, chemicals present in the ocean can be lofted into the gas or particle phase. One area of study will be to conduct a full and analytically rigorous characterization of the different organic nitrogen species present in particles found in marine environments. We will also examine the role of ocean-atmosphere exchange as an atmospheric source of organic nitrogen compounds by simultaneously measuring ocean water, the sea-surface microlayer and marine particles. Through this research, we will be able to better understand how the ocean contributes to the overall atmospheric burden of organic compounds. Amines are one of the most commonly detected classes of atmospheric organic nitrogen compounds. These have been shown to contribute to new particle formation, though their gas-phase fate remains poorly characterized. We will investigate the gas-phase atmospheric fate of amines using smog chamber experiments. In particular, we will examine the likelihood for one particular reaction, N-dealkylation, and determine the mechanism by which it occurs in the gas phase.This research addresses critical areas of uncertainty in the field of atmospheric chemistry. Results of this work will improve knowledge of particle nucleation, composition, and radiative effects, which are essential to increasing our understanding of the impact of atmospheric composition on climate and health.