Contribution of organic aerosols to reactive nitrogen deposition in South America

Abstract

Data from several in-situ studies suggest that the organic fraction in the total reactive nitrogen (Nr) atmospheric deposition is significant both worldwide and in South America. Uncertainties in its modeling are also very high and, typically, models tend to underestimate the organic fraction. The present project aims to reduce the gap between observational data and modeling results for organic nitrogen (ON) with focus on biomass burning emissions and its long-range transport and deposition processes and to achieve a better understanding of the organic fraction (ON) in the total reactive nitrogen atmospheric budget and deposition and how it might be related with the mass concentration and other parameters of relevant aerosol populations. In particular, it is proposed to investigate the relation between the organic fraction of the aerosol component as determined in SAMBBA campaign and the aerosol population modeled with CCATT-BRAMS. This BEPE internship is proposed for a nine months period and is the second of two. The first BEPE is proposed for a period of three months, with the objective of to compile a database of organic nitrogen budget and deposition in South America with the in-situ data available, including the data gathered at SAMBBA experiment. Both BEPE projects complement each other and contribute to the study of the contribution of organic aerosols to reactive nitrogen deposition in South America, in the frame of the PhD project "Atmospheric deposition of reactive nitrogen in South America" (Process 2012/09934-3). (AU)