Nutrients in atmospheric aerosol particles along the Atlantic Meridional Transect

The atmosphere can be an important source of nutrients to remote ocean waters, e.g., in supplying iron to nitrogen fixers in the tropical North Atlantic. We use results obtained from aerosol collection during four meridional transect cruises of the Atlantic Ocean in an attempt to identify sources of soluble nutrient species (Fe, N, P and Si) to the Atlantic atmosphere. The Sahara desert was the dominant source of soluble aerosol Fe and Si and also a significant source of aerosol P. Biomass burning and another source, possibly primary particles derived from vegetation, also contribute to the aerosol P loading. Industrial (NOx) and agricultural (ammonium) sources contribute to high nitrogen concentrations in the northern hemisphere, while biomass burning appears to be a significant seasonal source of N to the southern hemisphere. This work is an initial step in our aim to describe the atmospheric nutrient inputs to the Atlantic basin using a much larger set of aerosol and rain samples that will be obtained during the Atlantic Meridional Transect (AMT) project and other field campaigns.