Optical properties of the particles in the Crimea coastal waters (Black Sea)

Abstract

[1] A field experiment was carried out in summer 2002 on an oceanographic platform near the coast of Crimea, in the Black Sea. For the first time, the spectral volume scattering function (VSF) was measured for a wide range of scattering angles (i.e., from 0.6 to 177.3 degrees) using a recently developed device. Our analysis revealed that the mineral particles are the primary component influencing the scattering and backscattering coefficient in the study area. The good correlation obtained between the backscattering coefficient b bp and the nonalgal particles absorption coefficient showed that the absorption efficiency of the mineral particles is high in the second half of the experiment. The ratio Chla/c p (where Chla is the chlorophyll a concentration and c p is the beam attenuation coefficient) did not correlate with the backscattering ratio and thus could not be used in this experiment as an alternative proxy to estimate the bulk composition of the particles. The spectral variation of b p (the scattering coefficient) and b bp (the backscattering coefficient) was less steep than what can be found in the open ocean waters. That was explained by the influence of the absorption on the scattering process, especially in the blue, as a consequence of the anomalous dispersion. The average backscattering ratiõ b bp varied spectrally within 4%. Nevertheless, a high spectral variability ofb bp (around 30%) was observed suggesting that the use of a flat spectral variation is not accurate in coastal zones.

Optics and remote sensing of Bahamian carbonate sediment whitings and potential relationship to wind-driven Langmuir circulation

“…The measured ratio 5-6% is one of the highest values reported in natural waters and characteristic of water dominated by inorganic or mineral sediment Sullivan, et al, 2005;Whitmire et al, 2007). In turbid coastal waters of the Black Sea, for example, Chami et al (2005) foundb bp to be 4%. found high backscattering ratios around 5% from one sampling day in the Irish and Celtic Seas similar to these waters.…”

Variability in optical particle backscattering in contrasting bio‐optical oceanic regimes

“…4,b(140) is corrected for attenuation along the measurement path [the s(l) correction of Maffione and Dana 1997] using the beam attenuation coefficient measured in parallel (see later) and the total absorption coefficient derived from inversion of the diffuse attenuation coefficient for downward irradiance (K d ) and the irradiance reflectance (R) (eqs. 12 and 13 in Lee and Lewis (2003) and operated as described in Chami et al (2005). These data were used in complement to the Hydroscat data when analyzing b bp spectral dependence.…”

Retrieval of Water Constituents from Hyperspectral In-Situ Measurements under Variable Cloud Cover—A Case Study at Lake Stechlin (Germany)

“…is weakly dependent on wavelength in coastal and inland waters [48,49], and no information about its wavelength dependency was available for Lake Stechlin, a constant value derived from in-situ measurements was used (see Section 3.1).…”