@article{osburn_mikan_etheridge_burchell_birgand_2015, title={Seasonal variation in the quality of dissolved and particulate organic matter exchanged between a salt marsh and its adjacent estuary}, volume={120}, ISSN={2169-8953}, url={http://dx.doi.org/10.1002/2014JG002897}, DOI={10.1002/2014jg002897}, abstractNote={AbstractFluorescence was used to examine the quality of dissolved and particulate organic matter (DOM and POM) exchanging between a tidal creek in a created salt marsh and its adjacent estuary in eastern North Carolina, USA. Samples from the creek were collected hourly over four tidal cycles in May, July, August, and October 2011. Absorbance and fluorescence of chromophoric DOM (CDOM) and of base‐extracted POM (BEPOM) served as the tracers for organic matter quality while dissolved organic carbon (DOC) and base‐extracted particulate organic carbon (BEPOC) were used to compute fluxes. Fluorescence was modeled using parallel factor analysis (PARAFAC) and principle components analysis (PCA) of the PARAFAC results. Of nine PARAFAC components (C) modeled, C3 represented recalcitrant DOM and C4 represented fresher soil‐derived source DOM. Component 1 represented detrital POM, and C6 represented planktonic POM. Based on mass balance, recalcitrant DOC export was 86 g C m−2 yr−1 and labile DOC export was 49 g C m−2 yr−1; no planktonic DOC was exported. The marsh also exported 41 g C m−2 yr−1 of detrital terrestrial POC, which likely originated from lands adjacent to the North River estuary. Planktonic POC export from the marsh was 6 g C m−2 yr−1. Assuming the exported organic matter was oxidized to CO2 and scaled up to global salt marsh area, respiration of salt marsh DOC and POC transported to estuaries could amount to a global CO2 flux of 11 Tg C yr−1, roughly 4% of the recently estimated CO2 release for marshes and estuaries globally.}, number={7}, journal={Journal of Geophysical Research: Biogeosciences}, publisher={American Geophysical Union (AGU)}, author={Osburn, Christopher L. and Mikan, Molly P. and Etheridge, J. Randall and Burchell, Michael R. and Birgand, François}, year={2015}, month={Jul}, pages={1430–1449} }
 @article{osburn_handsel_mikan_paerl_montgomery_2012, title={Fluorescence Tracking of Dissolved and Particulate Organic Matter Quality in a River-Dominated Estuary}, volume={46}, ISSN={0013-936X 1520-5851}, url={http://dx.doi.org/10.1021/es3007723}, DOI={10.1021/es3007723}, abstractNote={Excitation-emission matrix (EEM) fluorescence was combined with parallel factor analysis (PARAFAC) to model base-extracted particulate (POM) and dissolved (DOM) organic matter quality in the Neuse River Estuary (NRE), North Carolina, before and after passage of Hurricane Irene in August 2011. Principle components analysis was used to determine that four of the PARAFAC components (C1-C3 and C6) were terrestrial sources to the NRE. One component (C4), prevalent in DOM of nutrient-impacted streams and estuaries and produced in phytoplankton cultures, was enriched in the POM and in surface sediment pore water DOM. One component (C5) was related to recent autochthonous production. Photoexposure of unfiltered Neuse River water caused an increase in slope ratio values (S(R)) which corresponded to an increase in the ratio C2:C3 for DOM, and the production of C4 fluorescence in both POM and DOM. Changes to the relative abundance of C4 in POM and DOM indicated that advection of pore water DOM from surface sediments into overlying waters could increase the autochthonous quality of DOM in shallow microtidal estuaries. Modeling POM and DOM simultaneously with PARAFAC is an informative technique that is applicable to assessments of estuarine water quality.}, number={16}, journal={Environmental Science & Technology}, publisher={American Chemical Society (ACS)}, author={Osburn, Christopher L. and Handsel, Lauren T. and Mikan, Molly P. and Paerl, Hans W. and Montgomery, Michael T.}, year={2012}, month={Jul}, pages={8628–8636} }