Seasonal variability in CDOM absorption and fluorescence properties in the Barataria Basin,Louisiana,USA

作     者：Shatrughan Singh Eurico D'Sa Erick Swenson 

作者机构：Department of Oceanography and Coastal SciencesLouisiana State University 

出 版 物：《Journal of Environmental Sciences》 (环境科学学报（英文版）)

年 卷 期：2010年第22卷第10期

页      面：1481-1490页

核心收录：

学科分类：081704[工学-应用化学] 07[理学] 0707[理学-海洋科学] 08[工学] 0817[工学-化学工程与技术] 070701[理学-物理海洋学] 0703[理学-化学] 070301[理学-无机化学] 

基　　金：support provided by the Minerals Management Service (MMS)-Coastal Marine Institute (CMI) Cooperative Agreement (1435- 0104CA32806) a NASA grant (No. NNA07CN12A) to E. D'Sa a Northern Gulf of Mexico Initiative (NGI)-Shell grant 

主　　题：Barataria Basin chromophoric dissolved organic matter CDOM fluorescence excitation-emission matrix 

摘      要：Absorption and fluorescence properties of chromophoric dissolved organic matter （CDOM） along a 124 km transect in the Barataria Basin, a large estuary located in Louisiana, USA, were investigated during high and low flow periods of the Mississippi River in the spring and winter of 2008-2009. Mean CDOM absorption at 355 nm from the marine to the freshwater end member stations ranged from （3.25 ± 0.56） to （20.76 ± 2.43） m^-1 for the three month high flow period whereas it varied from （1.48 ± 1.08） to （25.45 ± 7.03） m^-1 for the same stations during low flow period. Corresponding salinity values at these stations indicated the influence of river and shelf exchanges in the lower basin and precipitation and runoff in the upper basin. An inverse relationship of CDOM absorbance and fluorescence with salinity observed in the basin could he a useful indicator of salinity. CDOM fluorescence also varied over a large range showing an approximately 8 to 12-fold increase between the marine and freshwater end members for the two flow seasons. Excitation-emission matrix spectral plots indicated the presence of various fluorescence components with highest being the A-peak, lowest the T-peak, and the C and M-peaks showing similar trends along the transect. During low flow season the A/C ratio were well correlated with station locations indicating increased terrestrial influence towards the upper basin. CDOM absorption and fluorescence at 355 nm were highly correlated and independent of CDOM sources suggesting that fluorescence could be used to characterize CDOM in the basin.