Characterization of dissolved organic matter fluorescence in the South Atlantic Bight with use of PARAFAC model: Interannual variability
Characterization of dissolved organic matter fluorescence in the South Atlantic Bight with use of PARAFAC model: Interannual variability
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DOI：
10.1016/j.marchem.2009.01.015
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发表时间：
2009-02-20
期刊：
影响因子：
3
通讯作者：
Gonsior, Michael
中科院分区：
文献类型：
--
作者：
Kowalczuk, Piotr;Durako, Michael J.;Gonsior, Michael
作为长期沿海海洋研究和监测计划(CORMP)的一部分，对南大西洋海湾沿岸有色溶解有机物(CDOM)进行了系统的水样采集。从2001年10月到2005年3月，在3.5年的时间里，在开普福雷尔河出水口附近和邻近的昂斯洛湾(OB)采集了水样。在本研究期间，CFR流域有两种不同的水文和气象条件：2002年发生严重干旱，随后是2003年非常潮湿的一年。用350 nm吸收系数、谱斜率系数(S)和激发发射矩阵(EEM)荧光对CDOM进行了光学表征。利用平行因子分析(PARAFAC)对EEM光谱中的CDOM组分进行了分析，确定了6个组分：3个陆地类腐殖质组分、1个海洋类腐殖质组分和2个类蛋白质组分。在CFR的低盐度羽流中，陆地类腐殖质组分对溶解有机物(DOM)荧光的贡献最大。与CFR羽流区相比，OB区陆地类腐殖质对DOM荧光的贡献要小得多。在OB沿岸海域，类蛋白质组分对DOM荧光的贡献很大，在墨西哥湾流水域，它们是DOM荧光的主要成分。观测期间的水文条件对河口和近岸海域中CDOM的浓度和组成都有显著的影响。在CFR羽流中，干旱期间采集的样品与丰水期采集的样品之间的CDOM吸收和荧光强度存在一个数量级的差异。在干旱期间，CFR羽流中的CDOM由等比例的陆地类腐殖质组分(约占总荧光强度的60%)和显著的蛋白质类物质(约占总荧光强度的20%)组成。丰水期，CDOM主要由腐殖质组成(占总荧光的近75%)，蛋白质类物质贡献较小。淡水排放模式的变化对浮游植物中CDOM浓度和组成的影响也被观察到，尽管影响程度较小。(C)2009爱思唯尔B.V.保留所有权利。
Systematic water sampling for characterization of chromophoric dissolved organic matter (CDOM) in the coastal South Atlantic Bight, was conducted as part of the long term Coastal Ocean Research and Monitoring Program (CORMP). Water samples were collected during a 3.5 year period, from October 2001 until March 2005, in the vicinity of the Cape Fear River (CFR) outlet and in adjacent Onslow Bay (OB). During this study there were two divergent hydrological and meteorological conditions in the CFR drainage area: a severe drought in 2002, followed by the very wet year of 2003. CDOM was characterized optically by the absorption coefficient at 350 rim, the spectral slope coefficient (S), and by Excitation Emission Matrix (EEM) fluorescence. Parallel Factor Analysis (PARAFAC) was used to assess CDOM composition from EEM spectra and six components were identified: three terrestrial humic-like components, one marine humic-like component and two protein-like components. Terrestrial humic-like components contributed most to dissolved organic matter (DOM) fluorescence in the low salinity plume of the CFR. The contribution of terrestrial humic-like components to DOM fluorescence in OB was much smaller than in the CFR plume area. Protein-like components contributed significantly to DOM fluorescence in the coastal ocean of OB and they dominated DOM fluorescence in the Gulf Stream waters. Hydrological conditions during the observation period significantly impacted both concentration and composition of CDOM found in the estuary and coastal ocean. In the CFR plume, there was an order of magnitude difference in CDOM absorption and fluorescence intensity between samples collected during the drought compared to the wet period. During the drought, CDOM in the CFR plume was composed of equal proportions of terrestrial humic-like components (ca. 60% of the total fluorescence intensity) with a significant contribution of proteinaceous substances (ca. 20% of the total fluorescence). During high river flow, CDOM was composed mostly of humic substances (nearly 75% of total fluorescence) with minor contributions by proteinaceous substances. The impact of changes in fresh water discharge patterns on CDOM concentration and composition was also observed in OB, though to a lesser degree. (C) 2009 Elsevier B.V. All rights reserved.