Estimation of the absorption and the scattering coefficients of natural waters by use of underwater irradiance measurements

1994 ◽  
Vol 33 (15) ◽  
pp. 3276 ◽  
Author(s):  
John T. O. Kirk
Keyword(s):  
Natural Waters ◽  
Scattering Coefficients ◽  
Underwater Irradiance

scholarly journals Deriving inherent optical properties and associated uncertainties for the Dutch inland waters during the Eagle Campaign

2009 ◽  
Vol 6 (2) ◽  
pp. 2075-2098 ◽  
Author(s):  
M. S. Salama ◽  
Z. Su ◽  
C. M. Mannaerts ◽  
W. Verhoef
Keyword(s):  
Optical Properties ◽  
Natural Waters ◽  
Inland Waters ◽  
Absorption Coefficients ◽  
Water Turbidity ◽  
Modified Model ◽  
Scattering Coefficients ◽  
Inherent Optical Properties ◽  
Air Space

Abstract. During the Eagle 2006 campaign intensive in-situ and air/space borne measurements were carried out over the Wolderwijd and Veluwemeer natural waters in the Netherlands. In this paper, we modify the GSM semi-analytical inversion model for these lakes to derive inherent optical properties (IOPs) and their spectral dependencies from air and space borne data. Uncertainties of the derived IOPs are estimated using a nonlinear regression technique. The modified model succeeded in deriving accurate estimates of IOPs with R2 higher than 0.9 and RMSE values equal to 0.12 and 0.05 for absorption and scattering coefficients, respectively. Finally, we show that the uncertainty of derived absorption coefficients is slightly independent of absorption's magnitude. While the uncertainty of all derived IOPs increases with water turbidity.

Relationship between nephelometric turbidity and scattering coefficients in certain Australian waters

1980 ◽  
Vol 31 (1) ◽  
pp. 1 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Theoretical Calculations ◽  
Water Bodies ◽  
Published Data ◽  
Alternative Measure ◽  
Backscattering Coefficient ◽  
Scattering Parameter ◽  
Scattering Coefficients ◽  
South Wales ◽  
Underwater Irradiance ◽  
Radiance Distribution

It has been shown for five water bodies in the southern tablelands of New South Wales that there is a linear relationship between the nephelometric turbidity measured on water samples, and the value of 2RαK; where Rα is the asymptotic (maximum) value of underwater irradiance reflectance. and K is the vertical attenuation coefficient of irradiance, both measured in situ. An earlier theoretical analysis had shown that 2RαK should be equal to bb′, a new scattering parameter of the water, referred to as the asymptotic backscattering coefficient. The observed relationship between turbidity and 2RαK supports the interpretation of this latter parameter in terms of the scattering properties of the water. It is here proposed that bb′ (i.e. 2RαK) provides a useful alternative measure of light scattering by different waters. Theoretical calculations, using published data for underwater radiance distribution and volume scattering function for other water bodies, have been used to determine the ratios of the asymptotic backscattering coefficient, bb′. to the normal backscattering and total scattering coefficients (bb and b), for different types of water. The relationships which have been found may be used to obtain approximate values for these fundamental, but hard to measure. scattering coefficients.

Estimation of the scattering coefficient of natural waters using underwater irradiance measurements

1981 ◽  
Vol 32 (4) ◽  
pp. 533 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Attenuation Coefficient ◽  
Natural Waters ◽  
New Method ◽  
Scattering Coefficient ◽  
Published Data ◽  
Absorption Coefficients ◽  
A Value ◽  
South Wales ◽  
Underwater Irradiance ◽  
Beam Attenuation Coefficient

Certain relationships between irradiance reflectance (R), average cosine (μ) and the ratio of the scattering and absorption coefficients (b/a), previously derived by Monte Carlo simulation of underwater light, have been used as the basis for a new method of estimating the scattering and absorption coefficients of natural waters from irradiance measurements made within the water body concerned. Standard curves are presented from which, given R at a certain optical depth, the values of μ at that depth and b/a for the water may be read off. The product of μ and the vertical attenuation coefficient, KE for net downward irradiance, (Ed - Ea, provides an estimate of a; this multiplied by b/a then gives the value of b. When applied to published data for Lake Pend Oreille the method gives a value for b differing by only 5% from that which may be calculated by subtracting the absorption coefficient from the beam attenuation coefficient for that lake. Values for scattering coefficient have been calculated by the new method for five water bodies in the southern tablelands of New South Wales for various dates over a 3-year period. The values of b correlate very closely with nephelometric turbidity, an independent measure of light scattering. The new procedure gives higher values than those obtained by an earlier method, but is considered to be more accurate.

THE MECHANISM OF NITRATES TRANSFORMATION IN THE PROCESSES OF ELECTROCHEMICAL TREATMENT OF NATURAL WATERS

2002 ◽  
Vol 1 (3) ◽  
pp. 341-346
Author(s):  
Viorica Iambartev ◽  
Gheorghe Duca ◽  
Maria Gonta ◽  
Vera Matveevici
Keyword(s):  
Natural Waters ◽  
Electrochemical Treatment

DISTRIBUTION OF DISSOLVED METHANE IN SURFACE COASTAL WATERS OF THE NORTHEASTERN PART OF THE BLACK SEA

2017 ◽  
Author(s):  
Elena Kovaleva ◽  
Elena Kovaleva ◽  
Alexander Izhitskiy ◽  
Alexander Izhitskiy ◽  
Alexander Egorov ◽  
...  
Keyword(s):  
Black Sea ◽  
Natural Waters ◽  
Sea Water ◽  
The Black Sea ◽  
Methane Formation ◽  
Anthropogenic Pressure ◽  
Russian Science ◽  
Southeastern Part ◽  
Dissolved Methane ◽  
Continental Runoff

Studying of methane formation and distribution in natural waters is important for understanding of biogeochemical processes of carbon cycle, searching for oil and gas sections and evaluation of CH4 emissions for investigations of greenhouse effect. The Black Sea is the largest methane water body on our planet. However, relatively low values of methane concentration (closed to equilibrium with the atmospheric air) are typical of the upper aerobic layer. At the same time, the distribution pattern of CH4 in surface waters of coastal areas is complicated by the influence of coastal biological productivity, continental runoff, bottom sources, hydrodynamic processes and anthropogenic effect. The investigation is focused on the spatial variability of dissolved methane in the surface layer of the sea in coastal regions affected by the continental runoff and anthropogenic pressure. Unique in situ data on methane concentrations were collected along the ship track on 2 sections between Sochi and Gelendzhik (2013, 2014) and 2 sections between Gelendzhik and Feodosia (2015). Overall 170 samples were obtained. Gas-chromatographic analysis of the samples revealed increase of CH4 saturation in the southeastern part of the Crimean shelf and the Kerch Strait area. Such a pattern was apparently caused by the influence of the Azov Sea water spread westward along the Crimean shore from the strait. This work was supported by the Russian Science Foundation, Project 14-50-00095 and the Russian Foundation for Basic Research, Project 16-35-00156 mol_a.

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