A novel method to estimate DOC concentrations from CDOM absorption coefficients in coastal waters

Abstract

[1] A novel method to accurately retrieve DOC concentrations (±4%) from CDOM absorption coefficients, a g (l), at l = 275 and 295 nm is presented. By using these two wavelengths, the method exploits useful information about the ratio of a g (l) to [DOC] contained in the 275-295 nm spectral slope coefficient, S 275−295 . This approach was developed using data (n = 222) collected on a seasonal basis in surface waters of the Northern Gulf of Mexico. The approach is demonstrated to accurately and consistently estimate [DOC] for all seasons and for a broad [DOC] range of 63-611 mM. Application to coastal waters of the Beaufort Sea (n = 33) demonstrated that similar performance can be expected in other river-influenced ocean margins after parameterization using local data. Applicability to other marine environments remains to be tested but such assessment can be pursued immediately where appropriate data have already been collected. Citation: Fichot, C. G., and R. Benner (2011), A novel method to estimate DOC concentrations from CDOM absorption coefficients in coastal waters, Geophys. Res. Lett., 38, L03610,

Tracing the transport of colored dissolved organic matter in water masses of the Southern Beaufort Sea: relationship with hydrographic characteristics

“…In this study, we found that DOC concentrations were highly correlated with a CDOM (440) in the UPML (r 2 = 0.97), which is consistent with recent papers (e.g., Mannino et al, 2008;Fichot and Benner, 2011). In particular, our regression was similar with that obtained in the U.S. Middle Atlantic Bight (Mannino et al, 2008;DOC vs. a CDOM (440) relationship was obtained assuming a S CDOM of 0.018 nm −1 to convert a CDOM (412) to a CDOM (440)).…”

“…In contrast, there is a significant and positive correlation between this absorption and chlorophyll-a (chl-a) concentration in oceanic waters, suggesting phytoplankton-derived components contribute to CDOM (e.g., Bricaud et al, 2010). In addition, the spectral slope of CDOM absorption can give insights about sources and the bulk chemical properties of CDOM (Carder et al, 1989;Helms et al, 2008;Fichot and Benner, 2011), which are possibly influenced by photochemical and/or biological processes (e.g., Twardowski and Donaghay., 2002;Bricaud et al, 2010). Thus, CDOM absorption properties provide insights about source and physicochemical and biological processes.…”

Contribution to a bio-optical model for remote sensing of Lena River water

“…The spectral slopes are lower compared to mean Baltic and North Sea detritus absorption slopes, which are 0.013 and 0.0116 nm −1 , respectively (Babin et al, 2003a). Ferrari et al (2003) reported values between 0.0095 and 0.0125 nm −1 for the Baltic Sea. These are similar to values found in the NOMAD database (Werdell and Bailey, 2005) which are in the range 0.007-0.015 m −1 (5-95 % percentile).…”

Chromophoric Dissolved Organic Matter and Dissolved Organic Carbon from Sea-Viewing Wide Field-of-View Sensor (SeaWiFS), Moderate Resolution Imaging Spectroradiometer (MODIS) and MERIS Sensors: Case Study for the Northern Gulf of Mexico

“…Chromophoric DOM (CDOM), the colored component of DOM primarily absorbs light in the UV and visible spectral range affecting the intensity and spectral quality of the light field in the aquatic medium. Because in situ measurement and analysis of DOC is time-consuming and expensive [4,5], the potential for satellite estimates of DOC could provide a useful tool with synoptic and repeated coverage. However, DOC cannot be sensed directly by ocean color sensors; CDOM, the colored fraction of DOC, can be estimated remotely.…”