Improved Accuracy and Precision of Dissolved Organic Nitrogen and Inorganic Nitrogen in Seawater

University Of Delaware, Newark DE

Investigators

Abstract

ABSTRACT OCE-0352280 In the past decade, the international oceanographic community has demonstrated the ability for accurate measurements of dissolved organic carbon (DOC) in the ocean. The improved analytical ability is critical for understanding global carbon fluxes, which are needed to better assess global change. Also, consistent accurate analytical measurements are essential as we move toward the Twenty-first Century global observing systems. With better DOC measurements, new concepts have arisen regarding carbon distributions and fluxes, and accurate analytical capabilities will allow for additional understanding of the global carbon cycle in the near future. In the past several years, some progress has been made with DON analysis, but more research is needed before reliable measurements can be made on a routine basis. In this study, a researcher from the University of Delaware will improve the reliability and accuracy of the measurement of dissolved organic nitrogen (DON) in seawater. Recognizing that DON must be derived from the measurements of total dissolved nitrogen (TDN) and dissolved inorganic nitrogen (DIN), the researchers will first address the preparation and use of combined reference materials for measurement of TDN and DIN. Then, all available wet chemical and high temperature combustion (HTC) methods for TDN measurement will be further evaluated. A third objective is to improve reliability of measuring DOC and TDN by HTC methods. Protocols will be developed and tested for combined TDN and DIN analysis. The initial steps of the project will be made with close coordination between the researcher's laboratory and the Joint Global Ocean Flux Study time series stations in Bermuda (BATS) and Hawaii (HOT). Later in the project, reference materials and protocols will be extended to the international marine community for adoption using the time series stations as the norm. There are very few parameters in the field of marine biogeochemistry with documented standardization. The goal of this project is to make DOC and DON among them.