Journal of the European Optical Society - Rapid publications, Vol 6 (2011)

Assessment of the scattering by sub-micron particles in inland waters

M. L. Laanen, S. W. M. Peters, A. G. Dekker, H. J. van der Woerd


Current protocols prescribe 0.2 µm filters for absorption measurements of Coloured Dissolved Organic Matter (a(CDOM)). However, a large historical dataset of a(CDOM) was obtained over 0.7 µm filters. Since small particles may pass 0.7 µm filters, a(CDOM) was probably overestimated because of residual scattering. Furthermore, current protocols require suspended matter to be filtered over 0.7 µm. So the 0.2 µm - 0.7 µm fraction is missing from the particles and attributed to enhanced a(CDOM), potentially leading to poor optical closure. In this paper natural water samples from a eutrophic lake were analysed with both filter pore sizes and two different absorption determination methods. Besides a standard bench spectrometer with a cuvette a calibrated Point-Source integrating-Cavity Absorption Meter (PSICAM) was used to gauge the absorption measurements. After filtration over 0.7 µm we found a systematic 8% overestimation of a(CDOM) measured in the cuvette caused by residual scattering. By filtering over 0.2 µm the a(CDOM) cuvette values are 6% underestimated because also a significant fraction of absorption was removed from the sample. As a consequence we recommend testing for coloured residues on the 0.2 µm filter after prime filtration with a GF/F filter. In case of colouration, the method presented in this paper is a fast and simple check to correct the CDOM measurements.

© The Authors. All rights reserved. [DOI: 10.2971/jeos.2011.11046]

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A. Morel, and B. Gentili, "Diffuse reflectance of oceanic waters. II. Bidirectional aspects" Appl. Opt. 32, 6864-6879 (1993).

S. Sathyendranath, L. Prieur, and A. Morel, "A three-component model of ocean colour and its application to remote sensing of phytoplankton pigments in coastal waters" Int. J. Remote Sens. 10, 1373-1394 (1989).

G. Tilstone, G. F. Moore, R. Sørensen, R. Doerffer, R. Pasterkamp, and P. V. Jørgensen, "REVAMP Protocols. REVAMP methodologies Regional Validation of MERIS Chlorophyll products in North Sea coastal waters" ESA Publication EVG1 - CT - 2001 â_A¸S 00049, Noordwijk, Netherlands (2003).

J. T. O. Kirk, Light and photosynthesis in aquatic ecosystems (2nd edition, Cambridge University Press, Cambridge, 1994).

E. Aas, "Spectral Slope Of Yellow Substance: Problems Caused By Small Particles" in Proceedings to Ocean Optics XV (Ocean Optics, Monaco, 2002).

C. E. W. Steinberg, Ecology of Humic Substances in Freshwater, 1 (Springer, München, 2003).

R. Doerffer, "Protocols for the Validation of MERIS Water Products" ESA Publication PO-TN-MEL-GS-0043, 1-42 (Noordwijk, Netherlands, 2002).

S .G. H. Simis, M. Tijdens, H. L. Hoogveld, and H. J. Gons, "Optical signatures of the filamentous cyanobacterium Leptolyngbya boryana during mass viral lysis" Limnol. Oceanogr. 52, 184-197 (2007).

H. G. TrÃijper, and C. M. Yentsch, "Use of glass fiber filters for the rapid preparation of in vivo absorption spectra of photosynthetic bacteria" J. Bacteriol. 94, 1255-1256 (1967).

J. T. O. Kirk, "Modeling the performance of an integrating-cavity absorption meter: theory and calculations for a spherical cavity" Appl. Opt. 34, 4397-4408 (1995).

J. T. O. Kirk, "Point-source integrating-cavity absorption meter: theoretical principles and numerical modeling" Appl. Opt. 36, 6123-6127 (1997).

V. E. Brando, J. T. O. Kirk, P. J. Daniel, K. Oubelkheir, L. Clementson, and A. G. Dekker, "Measured sensitivity of the PSICAM: effects of anisotropic light source, fluorescence, temperature and salinity" in Proceedings to Ocean Optics XVII (Ocean Optics, Fremantle, 2004).

M. L. Laanen, Yellow Matters - Improving the remote sensing of Coloured Dissolved Organic Matter in inland freshwaters (Ph.D. dissertation, Vrije Universiteit Amsterdam, 2007).

R. Röttgers, C. Häse, and R. Doerffer, "Determination of the particulate absorption of microalgae using a point-source integratingcavity absorption meter: verification with a photometric technique, improvements for pigment bleaching, and correction for chlorophyll fluorescence" Limnol. Oceanogr.-meth. 5, 1-12 (2007).

R. Röttgers, and R. Doerffer, "Measurements of optical absorption by chromophoric dissolved organic matter using a point-source integrating cavity absorption meter" Limnol. Oceanogr.-meth. 5, 126-135 (2007).

A. G. Dekker, and S. W. M. Peters, "The use of the Thematic Mapper for the analysis of eutrophic lakes: A case study in The Netherlands" Int. J. Remote Sens. 14, 799-822 (1993).

K. Kalle, "The problem of the gelbstoff in the sea" Oceanogr. Mar. Biol. 4, 91-104 (1966).

A. Bricaud, A. Morel, and L. Prieur, "Absorption by dissolved organic matter of the sea (yellow substance) in the UV and visible domains" Limnol. Oceanogr. 26, 43-53 (1981).

S. A. Green, and N. V. Blough, "Optical absorption and fluorescence of chromophoric dissolved organic matter in natural waters" Limnol. Oceanogr. 39, 1903-1916 (1994).

C. A. Stedmon, S. Markager, and H. Kaas, "Optical Properties and Signatures of Chromophoric Dissolved Organic Matter (CDOM) in Danish Coastal Waters" Estuar. Coast. Shelf S. 51, 267-278 (2000).

C. J.-Y. Lerebourg, D. A. Pilgrim, G. D. Ludbrook, and R. Neal, "Development of a point source integrating cavity absorption meter" J. Opt. A-Pure Appl. Op. 4, 56-65 (2003).

R. Röttgers, W. Schoenfeld, P. Kipp, and R. Doerffer, "Practical test of a point-source integrating-cavity absorption meter (PSICAM): the performance of different collector assemblies" Appl. Opt. 44, 5549-5560 (2005).

R. M. Pope, and E. S. Fry, "Absorption spectrum (380-700 nm) of pure water, II. Integrating cavity measurements" Appl. Opt. 36, 8710-8723 (1997).

H. Buiteveld, J. H. M. Hakvoort, and M. Donze, "Optical properties of pure water" in Proceedings to Ocean Optics XII 174-183 (Washington, Ocean Optics, 1994).

R. A. Leathers, V. T. Downes, and C. O. Davis, "Analysis of a pointsource integrating-cavity absorption meter" Appl. Opt. 39, 1-10 (2000).

A. G. Dekker, V. E. Brando, P. J. Daniel, J. M. Anstee, and L. Clementson, "PSICAM - FROM MYTH TO REALITY" in Proceedings to the Seventh International Conference on Remote sensing for Marine and Coastal Environments (EPA, Miami, 2002).

E. Boss, W. H. Slade, M. Behrenfeld, and G. Dall'Olmo, "Acceptance angle effects on the beam attenuation in the ocean" Opt. Exp. 17, 1535-1550 (2009).

H. J. Van der Woerd, and R. Pasterkamp, "HYDROPT: A fast and flexible method to retrieve chlorophyll-a from multispectral satellite observations of optically complex coastal waters" Remote Sens. Environ. 112, 1795-1807 (2008).