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Full-Text Articles in Physical Sciences and Mathematics
Algorithm To Derive Inherent Optical Properties From Remote Sensing Reflectance In Turbid And Eutrophic Lakes, Kun Xue, Emmanuel Boss, Ronghua Ma, Ming Shen
Algorithm To Derive Inherent Optical Properties From Remote Sensing Reflectance In Turbid And Eutrophic Lakes, Kun Xue, Emmanuel Boss, Ronghua Ma, Ming Shen
Marine Sciences Faculty Scholarship
Inherent optical properties play an important role in understanding the biogeochemical processes of lakes by providing proxies for a variety of biogeochemical quantities, including phytoplankton pigments. However, to date, it has been difficult to accurately derive the absorption coefficient of phytoplankton [aph(λ)] in turbid and eutrophic waters from remote sensing. A large dataset of remote sensing of reflectance [ Rrs (λ)] and absorption coefficients was measured for samples collected from lakes in the middle and lower reaches of the Yangtze River and Huai River basin (MLYHR), China. In the process of scattering correction of spectrophotometric measurements, the particulate absorption coefficients …
Method For Estimating Mean Particle Size From High-Frequency Fluctuations In Beam Attenuation Or Scattering Measurements, Nathan T. Briggs, Wayne H. Slade, Emmanuel Boss, Mary Jane Perry
Method For Estimating Mean Particle Size From High-Frequency Fluctuations In Beam Attenuation Or Scattering Measurements, Nathan T. Briggs, Wayne H. Slade, Emmanuel Boss, Mary Jane Perry
Marine Sciences Faculty Scholarship
The ability to estimate mean particle size using simple, low-power optical instruments promises to greatly expand coverage of particle size measurements in the ocean and advance understanding of myriad processes from sediment transport to biological carbon sequestration. Here we present a method for estimating the mean diameter of particles in suspension from high-resolution time series of simple optical measurements, such as beam attenuation or optical backscattering. Validation results from a laboratory clay aggregation experiment show a good fit with independent mean particle diameter estimates in the 10-80 μm diameter range, with relative biases of 17%-38% and relative root mean square …
Effects Of Particle Aggregation And Disaggregation On Their Inherent Optical Properties, Wayne H. Slade, Emmanuel Boss, Clementina Russo
Effects Of Particle Aggregation And Disaggregation On Their Inherent Optical Properties, Wayne H. Slade, Emmanuel Boss, Clementina Russo
Marine Sciences Faculty Scholarship
In many environments a large portion of particulate material is contained in aggregated particles; however, there is no validated framework to describe how aggregates in the ocean scatter light. Here we present the results of two experiments aiming to expose the role that aggregation plays in determining particle light scattering properties, especially in sedimentdominated coastal waters. First, in situ measurements of particle size distribution (PSD) and beam-attenuation were made with two laser particle sizing instruments (one equipped with a pump to subject the sample to aggregate-breaking shear), and measurements from the two treatments were compared. Second, clays were aggregated in …
Effect Of Particulate Aggregation In Aquatic Environments On The Beam Attenuation And Its Utility As A Proxy For Particulate Mass, Emmanuel Boss, Wayne Slade, Paul Hill
Effect Of Particulate Aggregation In Aquatic Environments On The Beam Attenuation And Its Utility As A Proxy For Particulate Mass, Emmanuel Boss, Wayne Slade, Paul Hill
Marine Sciences Faculty Scholarship
Marine aggregates, agglomerations of particles and dissolved materials, are an important particulate pool in aquatic environments, but their optical properties are not well understood. To improve understanding of the optical properties of aggregates, two related studies are presented. In the first, an in situ manipulation experiment is described, in which beam attenuation of undisturbed and sheared suspensions are compared. Results show that in the sheared treatment bulk particle size decreases and beam attenuation increases, consistent with the hypothesis that a significant fraction of mass in suspension is contained in fragile aggregates. Interestingly, the magnitude of increase in beam attenuation is …
Acceptance Angle Effects On The Beam Attenuation In The Ocean, Emmanuel Boss, Wayne H. Slade, M. Behrenfeld, G. Dall'olmo
Acceptance Angle Effects On The Beam Attenuation In The Ocean, Emmanuel Boss, Wayne H. Slade, M. Behrenfeld, G. Dall'olmo
Marine Sciences Faculty Scholarship
The beam attenuation serves as a proxy for particulate matter and is a key parameter in visibility algorithms for the aquatic environment. It is well known, however, that the beam attenuation is a function of the acceptance angle of the transmissometer used to measure it. Here we compare eight different transmissometers with four different acceptance angles using four different deployment strategies and sites, and find that their mean attenuation values differ markedly and in a consistent way with instrument acceptance angle: smaller acceptance angles provide higher beam attenuation values. This difference is due to variations in scattered light collected with …