RUI: Temporal Variability of Chromophoric Dissolved Organic Carbon (CDOM) in Rainwater: Photochemical Effects and Influence on Trace Metal Speciation

University Of North Carolina At Wilmington, Wilmington NC

Investigators

Abstract

Little is currently known as to the nature of light-sensitive dissolved organic matter in rainwater, despite such matter comprising the majority of carbon present in precipitation. This Research in Undergraduate Institution (RUI) project continues a series of studies by these investigators on rainwater chemistry, with a new and novel focus on the photochemistry of chromophoric dissolved organic matter (CDOM). This process will be characterized by quantitatively determining how selected trace metals affect the quantum efficiency and rate of CDOM photodegradation and photo-bleaching under a variety of conditions representative of the ambient environment. Results from this study will increase understanding of atmospheric oxidative capacity, the fate of dissolved organic matter in rainwater, and biosphere/biota response to climate-induced changes in incident ultraviolet radiation. New information on the physical and chemical factors determining the nature, reactivity and fate of CDOM in rainwater will be especially useful for constraining new generation climate models. Broader community impacts include bringing highly relevant and timely climate-related research to the undergraduate classroom at the host institution, thereby challenging the next generation of young geoscientists with important and engaging real-world issues and problems.