Correlation between zooplankton population and the volume‐scattering coefficient

1975 ◽  
Vol 58 (S1) ◽  
pp. S101-S101
Author(s):  
W. B. Anderson
Keyword(s):  
Scattering Coefficient ◽  
Volume Scattering ◽  
Zooplankton Population

A phase matrix for a dense discrete random medium: evaluation of volume scattering coefficient

1996 ◽  
Vol 34 (5) ◽  
pp. 1137-1143 ◽  
Author(s):  
Hean-Teik Chuah ◽  
S. Tjuatja ◽  
A.K. Fung ◽  
J.W. Bredow
Keyword(s):  
Random Medium ◽  
Scattering Coefficient ◽  
Volume Scattering

scholarly journals Inversion of the volume scattering function and spectral absorption in coastal waters with biogeochemical implications

2013 ◽  
Vol 10 (6) ◽  
pp. 9003-9041
Author(s):  
X. Zhang ◽  
Y. Huot ◽  
D. J. Gray ◽  
A. Weidemann ◽  
W. J. Rhea
Keyword(s):  
Absorption Spectra ◽  
Coastal Waters ◽  
Chlorophyll Concentration ◽  
Hplc Method ◽  
Scattering Coefficient ◽  
Spectral Absorption ◽  
Volume Scattering ◽  
Total Scattering ◽  
Inherent Optical Properties ◽  
Complete Set

Abstract. In the aquatic environment, particles can be broadly separated into phytoplankton (PHY), non-algal particle (NAP) and dissolved (or very small particle, VSP) fractions. Typically, absorption spectra are inverted to quantify these fractions, but volume scattering functions (VSFs) can also be used. Both absorption spectra and VSFs were used to calculate particle fractions for an experiment in Chesapeake Bay. A complete set of water inherent optical properties was measured using a suite of commercial instruments and a prototype Multispectral Volume Scattering Meter (MVSM); the chlorophyll concentration, [Chl] was determined using the HPLC method. The total scattering coefficient (measured by an ac-s) and the VSF (at a few backward angles, measured by a HydroScat 6 and an ECO-VSF) agreed with the LISST and MVSM data within 5%, thus indicating inter-instrument consistency. The size distribution and scattering parameters for PHY, NAP and VSP were inverted from measured VSFs. For the absorption inversion, the "dissolved" absorption spectra were measured for filtrate passing through a 0.2 μm filter, whereas [Chl] and NAP absorption spectra were inverted from the particulate fraction. Even though the total scattering coefficient showed no correlation with [Chl], estimates of [Chl] from the VSF-inversion agreed well with the HPLC measurements (r = 0.68, mean relative error s = −20%). The scattering associated with NAP and VSP both correlated well with the NAP and "dissolved" absorption coefficients, respectively. While NAP dominated forward, and hence total, scattering, our results also suggest that the scattering by VSP was far from negligible and dominated backscattering.

Reconstruction of volume scattering coefficient with considering seabottom scattering layer

2019 ◽  
Vol 146 (4) ◽  
pp. 2929-2929
Author(s):  
Polina Vornovskikh ◽  
Andrei Sushchenko ◽  
Igor Prokhorov
Keyword(s):  
Scattering Coefficient ◽  
Scattering Layer ◽  
Volume Scattering

scholarly journals Biogeochemical origins of particles obtained from the inversion of the volume scattering function and spectral absorption in coastal waters

2013 ◽  
Vol 10 (9) ◽  
pp. 6029-6043 ◽  
Author(s):  
X. Zhang ◽  
Y. Huot ◽  
D. J. Gray ◽  
A. Weidemann ◽  
W. J. Rhea
Keyword(s):  
Absorption Spectra ◽  
Chlorophyll Concentration ◽  
Hplc Method ◽  
Scattering Coefficient ◽  
Volume Scattering ◽  
Total Scattering ◽  
Inherent Optical Properties ◽  
Dissolved Matter ◽  
Complete Set ◽  
Relative Errors

Abstract. In the aquatic environment, particles can be broadly separated into phytoplankton (PHY), non-algal particle (NAP) and dissolved (or very small particle, VSP) fractions. Typically, absorption spectra are inverted to quantify these fractions, but volume scattering functions (VSFs) can also be used. Both absorption spectra and VSFs were used to estimate particle fractions for an experiment in the Chesapeake Bay. A complete set of water inherent optical properties was measured using a suite of commercial instruments and a prototype Multispectral Volume Scattering Meter (MVSM); the chlorophyll concentration, [Chl] was determined using the HPLC method. The total scattering coefficient measured by an ac-s and the VSF at a few backward angles measured by a HydroScat-6 and an ECO-VSF agreed with the LISST and MVSM data within 5%, thus indicating inter-instrument consistency. The size distribution and scattering parameters for PHY, NAP and VSP were inverted from measured VSFs. For the absorption inversion, the "dissolved" absorption spectra were measured for filtrate passing through a 0.2 μm filter, whereas [Chl] and NAP absorption spectra were inverted from the particulate fraction. Even though the total scattering coefficient showed no correlation with [Chl], estimates of [Chl] from the VSF-inversion agreed well with the HPLC measurements (r = 0.68, mean relative errors = −20%). The scattering associated with NAP and VSP both correlated well with the NAP and "dissolved" absorption coefficients, respectively. While NAP dominated forward, and hence total, scattering, our results also suggest that the scattering by VSP was far from negligible and dominated backscattering. Since the sizes of VSP range from 0.02 to 0.2 μm, covering (a portion of) the operationally defined "dissolved" matter, the typical assumption that colored dissolved organic matter (i.e., CDOM) does not scatter may not hold, particularly in a coastal or estuarine environment.

Correlations between the Parameters of the Light Volume Scattering Functions in the Mediterranean Sea Surface Waters

2021 ◽  
Vol 28 (5) ◽  
Author(s):  
V. I. Mankovsky ◽  
E. V. Mankovskaya ◽  
◽  
Keyword(s):  
Mediterranean Sea ◽  
Suspended Matter ◽  
Variation Coefficient ◽  
Scattering Coefficient ◽  
Asymmetry Coefficient ◽  
Volume Scattering ◽  
Total Scattering ◽  
Angle Scattering ◽  
The Asymmetry ◽  
The Mediterranean

Purpose. The aim of the work is to study relationships between the parameters of the light volume scattering functions based on the data of their measurements in the Mediterranean Sea surface waters. Methods and Results. The data of measurements of the light volume scattering functions in the water samples taken in a few regions of the southern Mediterranean Sea, namely from the Strait of Gibraltar to the Levant Sea, as well as in the central part of the Aegean Sea and near the Dardanelles Strait (May, 1998) were used. The following parameters of the volume scattering functions were calculated: total scattering coefficient, and asymmetry and variation coefficients. The maximum and minimum values of the scattering coefficient were 0.21 and 0.09 m–1, respectively; and those for the asymmetry coefficient – 77.8 and 33.9. The variation coefficient of the angle scattering coefficients changed within 35–79%, its maximum and minimum values fell on the angles 7.5° and 162.5°, respectively. Obtained were the relations between the variation coefficient and the scattering angle, the asymmetry coefficient and the scattering coefficient, and the angle scattering coefficients and the total scattering coefficient. All of them possess high (more than 0.9) correlation coefficients. The coefficient value (51.7%) at the angle 2° does not correspond to general relation of the variation coefficient to the scattering angle. This fact is explained by different contributions of coarse and fine suspended matter to the light volume scattering function. At the angle 2°, the main contribution is made by a coarse (organic) suspended matter, whereas at the angles exceeding 7.5° – by a fine (mineral) suspension. Conclusions. The values of the variation coefficient of the angle scattering coefficient at the angles equal to 2° and exceeding 7.5° demonstrate variability of the coarse and fine suspended matter in the Mediterranean Sea, respectively. The equation for the relation between the asymmetry coefficient of the light volume scattering functions and the total scattering coefficient obtained for the Mediterranean Sea waters is close to the analogous one obtained for the Atlantic Ocean tropical waters. The angle 3.5° is optimal for determining the total scattering coefficient using the angle scattering coefficient for the Mediterranean Sea functions.

The Relationship between the Inherent and the Apparent Optical Properties of Surface Waters and its Dependence on the Shape of the Volume Scattering Function

Ocean Optics ◽  
1994 ◽  
Author(s):  
John T. O. Kirk
Keyword(s):  
Optical Properties ◽  
Absorption Coefficient ◽  
Water Body ◽  
Small Sample ◽  
Scattering Coefficient ◽  
Scattering Function ◽  
Parallel Beam ◽  
Volume Scattering ◽  
Inherent Optical Properties ◽  
Aquatic Medium

Let us begin by reminding ourselves just what we mean by “the inherent optical properties” and “the apparent optical properties” of surface waters. The inherent optical properties are those that belong to the aquatic medium itself: properties that belong to a small sample of the aquatic medium taken out of the water body just as much as they belong to a great mass of the medium existing within the water body itself. The properties of particular concern to us are the absorption coefficient, a, the scattering coefficient, b, and the volume scattering function, β(θ). The absorption coefficient at a given wavelength is a measure of the intensity with which the medium absorbs light from a parallel beam per unit pathlength of medium (see Eq. 1.18). The scattering coefficient at a given wavelength is a measure of the intensity with which the medium scatters light from a parallel beam per unit pathlength of medium (see Eq. 1.17). Both a and b have the units, m-1. The normalized volume scattering function specifies the angular (θ) distribution of single-event scattering around the direction of a parallel incident beam. It is often normalized to total scattering and referred to as the scattering phase function, P(θ) (see Eq. 1.21). Since these properties belong, as I have already said, to a small sample of the medium, just as much as they do to a great slab of ocean, they can be measured in the laboratory. The absorption coefficients at various wavelengths can be measured with a suitable spectrophotometer: the scattering coefficient and the volume scattering function can be measured with a light scattering photometer. The apparent optical properties are not properties of the aquatic medium as such although they are closely dependent on the nature of the aquatic medium. In reality they are properties of the light field that, under the incident solar radiation stream, is established within the water body.

Molecular-Backscatter Lidar Profiling of the Volume-Scattering Coefficient in Cirrus

Cirrus ◽  
2002 ◽  
Author(s):  
Albert Ansmann
Keyword(s):  
Background Radiation ◽  
Interference Filter ◽  
Laser Wavelength ◽  
Scattering Coefficient ◽  
High Spectral Resolution ◽  
Raman Lidar ◽  
Backscatter Coefficient ◽  
Volume Scattering ◽  
Backscatter Radiation ◽  
Raman Backscatter

Backscatter and polarization lidars have already been used extensively to investigate ice clouds (see chapters 2 and 10). A severe limitation is that trustworthy values of the volume-scattering coefficient, one of the most important parameters in the description of the impact of cirrus on climate, cannot be derived from data taken with these lidars. Even the retrieved cirrus backscatter-coefficient profile is often questionable. A discussion of achievements and limitations of the lidar method can be found in the literature (e.g., Fernald et al. 1972; Klett 1981; Fernald 1984; Klett 1985; Sasano et al. 1985; Bissonnette 1986; Ansmann et al. 1992b; Kovalev 1995). The procedure, with all its subsequent modifications and improvements, suffers from the fact that two physical quantities, the particle backscatter coefficient and the particle extinction coefficient, must be determined from only one lidar signal. The uncertainties in the estimated optical parameters are especially large in cirrus, in which the relationship between particle extinction and backscattering can vary strongly in space and time. The situation improved significantly when the first molecular (Raman)-backscatter lidar experiments demonstrated that accurate extinction profiling throughout the entire troposphere is possible (Ansmann et al. 1990, 1992b). After the Pinatubo eruption, it was shown that even at stratospheric heights profiles of the volume-scattering coefficient can easily be obtained with a Raman lidar (Ansmann et al. 1991, 1993a, 1997; Ferrare et al. 1992; Gross et al. 1995; Donavan und Carswell 1997). Two types of molecular-backscatter lidars for extinction measurements are available. The Raman lidar measures lidar return signals elastically backscattered by air molecules and particles and inelastically (Raman) backscattered by nitrogen and/or oxygen molecules (Cooney et al. 1969; Melfi 1972; Ansmann et al. 1992a; Whiteman et al. 1992; Reichardt et al. 1996). Interference-filter polychromators and double-grating monochromators (Arshinov et al. 1983; Wandinger et al. 1998) are used to separate the aerosol signal from the vibrational-rotational or pure rotational Raman signals, to reduce the sky background radiation, and, for the Raman channels, to block the strong elastic-backscatter radiation at the laser wavelength. The suppression has to be better than 10-8. The second type of a molecular-backscatter lidar is the High Spectral Resolution Lidar (HSRL).

Sign in / Sign up

Export Citation Format

Share Document