Atmospheric deposition is an important, but poorly quantified, mode of transport of low-solubility trace elements and their isotopes (TEI) from the continents to the surface waters of the ocean. For iron, cobalt, and zinc, three essential micronutrients for phytoplankton growth, atmospheric inputs may be the critical pathway for maintaining biologically necessary concentrations of the metals in surface waters. An investigator from Florida State University plans to ensure that aerosols and rainwater samples are collected and analyzed as part of the GEOTRACES Program. To this end, he proposes to acquire the necessary equipment, namely a high-volume sampler for the collection of total aerosols and size-fractionated aerosols on low-blank filter matrices, as well as an automated rainwater sampling system for the collection of large volumes of unfiltered and filtered rainfall. In addition, the proponent proposes develop the necessary protocols to accurately and precisely collect aerosol/rainwater samples and analyze them for trace metals during the GEOTRACES intercalibration effort. The acquired systems would be made available for deployment on subsequent GEOTRACES research cruises and the systems can be subsampled and these shared with colleagues around the world.
In terms of broader impacts, a manual on the how-to's of atmospheric sampling and analyses would be produced for use by the national and international science community. One postdoc would be supported and trained as part of this project, and students would also be included in the study.
