Yellow substance (gelbstoff) and its contribution to the attenuation of photosynthetically active radiation in some inland and coastal south-eastern Australian waters

1976 ◽  
Vol 27 (1) ◽  
pp. 61 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Absorption Coefficient ◽  
Photosynthetically Active Radiation ◽  
Natural Waters ◽  
Sea Water ◽  
Light Attenuation ◽  
Active Radiation ◽  
South Eastern ◽  
Yellow Substance ◽  
Eastern Australia ◽  
Coastal Sea

The absorption spectra relative to distilled water of samples from various inland and coastal waters in south-eastern Australia (New South Wales and the Australian Capital Territory) have been measured. Amongst the freshwater samples the level of dissolved yellow substance (gelbstoff) was found to vary seven-fold (the base-10 logarithm absorption coefficient at 440 nm ranged from 0.42 to 2.90 m-1). In coastal sea water the concentration was much lower than in any of the freshwater samples (absorption coefficient 0.01-0.08 m-1 at 440 nm). Calculations have been carried out of the contribution made by yellow substance to attenuation of photosynthetically active radiation (PAR). In the inland waters yellow substance has a dominating influence on light attenuation, reducing the amount of PAR many-fold, and the blue region of the spectrum is abolished at quite moderate depths. In all cases except sea water it was calculated that most (60-80%) of the quanta captured are absorbed by yellow substance rather than by water. An alternative name, 'gilvin' (Latin, gilvus = pale yellow), for the yellow pigments in natural waters, to replace 'yellow substance' or 'gelbstoff ', is suggested.

Use of a quanta meter to measure attenuation and underwater reflectance of photosynthetically active radiation in some inland and coastal south-eastern Australian waters

1977 ◽  
Vol 28 (1) ◽  
pp. 9 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Attenuation Coefficient ◽  
Water Body ◽  
Coastal Waters ◽  
Photosynthetically Active Radiation ◽  
Inland Waters ◽  
Backscattering Coefficient ◽  
Active Radiation ◽  
South Eastern ◽  
Yellow Substance ◽  
Eastern Australia

The attenuation of total photosynthetically active radiation (PAR) in natural waters and its characterization by means of a vertical attenuation coefficient are briefly discussed. The factors determining underwater reflectance (ratio of upward to downward irradiance at a given depth) are considered, and a simple mathematical treatment is presented which leads to the conclusion that within that part of the water body where the asymptotic radiance distribution exists, if reflection from the bottom is negligible then the reflectance is equal to the asymptotic backscattering coefficient (defined in the text) divided by 2K, where K is the (natural logarithm) vertical attenuation coefficient. Data collected using a commercially available quantum irradiance meter over a 2-year period for various inland and coastal waters in south-eastern Australia are presented together with measure- ments of levels of yellow substance and phytoplankton. In the turbid inland waters attenuation of PAR closely follows an exponential law. In the much clearer coastal waters, by contrast, attenuation of PAR is approximately biphasic, the vertical attenuation coefficient in the upper few metres being noticeably higher than that at greater depths. Within any one water body the vertical attenuation coefficient was observed to vary up to four-fold during the 2-year period: nevertheless there were indications that the average attenuation of PAR tended to differ characteristically from one water body to another. In one of the inland waters, measurements at different times of day showed that the vertical attenuation coefficient was not strongly dependent on solar altitude. Underwater reflectance values in the inland waters were surprisingly high (0.04-0.21) compared to values in the literature: this is probably a consequence of the high turbidity of these waters. Calculated values of the asymptotic backscattering coefficient for the inland lakes are presented. It is suggested that measurements of yellow substance and phytoplankton, together with some estimate of light scattering, in parallel with measurements of attenuation of PAR would facilitate an understanding of the factors responsible for that attenuation.

Spectral Distribution of Photosynthetically Active Radiation in some South-eastern Australian Waters

1979 ◽  
Vol 30 (1) ◽  
pp. 81 ◽  
Author(s):  
JTO Kirk
Keyword(s):  
Blue Light ◽  
Photosynthetically Active Radiation ◽  
Spectral Distribution ◽  
Light Attenuation ◽  
Red Light ◽  
Extreme Case ◽  
Euphotic Zone ◽  
Active Radiation ◽  
South Eastern ◽  
Eastern Australia

The results are presented of a study of the spectral distribution of photosynthetically active radiation (PAR) in some inland, and one coastal, waters in south-eastern Australia, carried out with a submersible spectroradiometer. There is particularly rapid attenuation with depth of blue light in the 400-500-nm waveband, due to the yellow substances ('gilvin', 'gelbstoff') in the waters. Attenuation in the red region, due to absorption by water itself, is clearly evident but is generally much less steep than that in the blue. Within the rather shallow euphotic zone typical of these waters the available PAR is impoverished in blue light but still contains plenty of red (630-700-nm) light. At greater depths, in waters of moderate turbidity, a spectral distribution strongly peaked at about 580 nm, with a shoulder at about 630 nm, is obtained. Although the contribution of phytoplankton can be significant, in general in these turbid inland waters suspended soil particles contribute more to vertical light attenuation. This is partly due to the increased pathlength of the photons caused by scattering, but direct absorption of light, especially in the blue region, by the particulate inanimate 'tripton' is suggested by the data. Turbidity and dis- solved colour of the water tend to increase together: in particularly turbid, yellow waters the spectral distribution of PAR is shifted to longer wavelengths and in an extreme case consisted of quite a sharp peak at 700 nm. In the clear, comparatively colourIess coastal-estuarine waters of Batemans Bay (N.S.W.), blue light was attenuated less steeply than red light, so that the underwater spectral distribution, although peaked at about 570 nm, was (at 4 m) still quite rich in blue as well as red light.

scholarly journals Carbon monoxide apparent quantum yields and photoproduction in the Tyne estuary

2011 ◽  
Vol 8 (3) ◽  
pp. 703-713 ◽  
Author(s):  
A. Stubbins ◽  
C. S. Law ◽  
G. Uher ◽  
R. C. Upstill-Goddard
Keyword(s):  
Carbon Monoxide ◽  
Natural Waters ◽  
Sea Water ◽  
River Estuary ◽  
Quantum Yields ◽  
Absorption Data ◽  
Coastal Sea ◽  
Order Of Magnitude ◽  
Good Proxy ◽  
Minimum Estimate

Abstract. Carbon monoxide (CO) apparent quantum yields (AQYs) are reported for a suite of riverine, estuarine and sea water samples, spanning a range of coloured dissolved organic matter (CDOM) sources, diagenetic histories, and concentrations (absorption coefficients). CO AQYs were highest for high CDOM riverine samples and almost an order of magnitude lower for low CDOM coastal seawater samples. CO AQYs were between 47 and 80% lower at the mouth of the estuary than at its head. Whereas, a conservative mixing model predicted only 8 to 14% decreases in CO AQYs between the head and mouth of the estuary, indicating that a highly photoreactive pool of terrestrial CDOM is lost during estuarine transit. The CDOM absorption coefficient (a) at 412 nm was identified as a good proxy for CO AQYs (linear regression r2 > 0.8; n = 12) at all CO AQY wavelengths studied (285, 295, 305, 325, 345, 365, and 423 nm) and across environments (high CDOM river, low CDOM river, estuary and coastal sea). These regressions are presented as empirical proxies suitable for the remote sensing of CO AQYs in natural waters, including open ocean water, and were used to estimate CO AQY spectra and CO photoproduction in the Tyne estuary based upon annually averaged estuarine CDOM absorption data. A minimum estimate of annual CO production was determined assuming that only light absorbed by CDOM leads to the formation of CO and a maximum limit was estimated assuming that all light entering the water column is absorbed by CO producing photoreactants (i.e. that particles are also photoreactive). In this way, annual CO photoproduction in the Tyne was estimated to be between 0.99 and 3.57 metric tons of carbon per year, or 0.004 to 0.014% of riverine dissolved organic carbon (DOC) inputs to the estuary. Extrapolation of CO photoproduction rates to estimate total DOC photomineralisation indicate that less than 1% of DOC inputs are removed via photochemical processes during transit through the Tyne estuary.

scholarly journals GIS tool to predict photosynthetically active radiation in a Dry Valley

2020 ◽  
Vol 32 (5) ◽  
pp. 315-328
Author(s):  
Dimitri Acosta ◽  
Peter T. Doran ◽  
Madeline Myers
Keyword(s):  
Primary Productivity ◽  
Photosynthetically Active Radiation ◽  
Net Primary Productivity ◽  
Light Attenuation ◽  
Statistical Treatment ◽  
Ground Truth ◽  
Research Area ◽  
Research Network ◽  
Ground Truth Data ◽  
Active Radiation

AbstractUnderstanding primary productivity is a core research area of the National Science Foundation's Long-Term Ecological Research Network. This study presents the development of the GIS-based Topographic Solar Photosynthetically Active Radiation (T-sPAR) toolbox for Taylor Valley. It maps surface photosynthetically active radiation using four meteorological stations with ~20 years of data. T-sPAR estimates were validated with ground-truth data collected at Taylor Valley's major lakes during the 2014–15 and 2015–16 field seasons. The average daily error ranges from 0.13 mol photons m-2 day-1 (0.6%) at Lake Fryxell to 3.8 mol photons m-2 day-1 (5.8%) at Lake Hoare. We attribute error to variability in terrain and sun position. Finally, a user interface was developed in order to estimate total daily surface photosynthetically active radiation for any location and date within the basin. T-sPAR improves upon existing toolboxes and models by allowing for the inclusion of a statistical treatment of light attenuation due to cloud cover. The T-sPAR toolbox could be used to inform biological sampling sites based on radiation distribution, which could collectively improve estimates of net primary productivity, in some cases by up to 25%.

scholarly journals Carbon monoxide apparent quantum yields and photoproduction in the estuary Tyne

2010 ◽  
Vol 7 (5) ◽  
pp. 7421-7448 ◽  
Author(s):  
A. Stubbins ◽  
C. S. Law ◽  
G. Uher ◽  
R. C. Upstill-Goddard
Keyword(s):  
Carbon Monoxide ◽  
Natural Waters ◽  
Sea Water ◽  
River Estuary ◽  
Quantum Yields ◽  
Absorption Data ◽  
Coastal Sea ◽  
Order Of Magnitude ◽  
Good Proxy ◽  
Seawater Samples

Abstract. Carbon monoxide (CO) apparent quantum yields (AQYs) are reported for a suite of riverine, estuarine and sea water samples, spanning a range of coloured dissolved organic matter (CDOM) sources, diagenetic histories, and concentrations (absorption coefficients). CO AQYs were highest for high CDOM riverine samples and almost an order of magnitude lower for low CDOM coastal seawater samples. A conservative mixing model predicted only 4% decreases in CO AQYs between the head and mouth of the estuary, whereas measured reductions in CO AQYs were between 47 and 80%, indicating that a highly photoreactive pool of terrestrial CDOM is lost during estuarine transit. The CDOM absorption coefficient (a) at 412 nm was identified as a good proxy for CO AQYs (linear regression r>20.8; n=12) at all CO AQY wavelengths studied (285, 295, 305, 325, 345, 365, and 423 nm) and across environments (high CDOM river, low CDOM river, estuary and coastal sea). These regressions are presented as empirical proxies suitable for the remote sensing of CO AQYs in natural waters, including open ocean water and were used to estimate CO AQY spectra and CO photoproduction in the Tyne estuary based upon annually averaged estuarine CDOM absorption data. Annual CO photoproduction in the Tyne was estimated to be between 1.38 and 3.57 metric tons of carbon per year, or 0.005 to 0.014% of riverine dissolved organic carbon (DOC) inputs to the estuary. Extrapolation of CO photoproduction rates to estimate total DOC photomineralisation indicate that less than 1% of DOC inputs are removed via photochemical processes during transit through the Tyne estuary.

Evaluating plant photosynthetic traits via absorption coefficient in the photosynthetically active radiation region

2021 ◽  
Vol 258 ◽  
pp. 112401
Author(s):  
Anatoly Gitelson ◽  
Timothy Arkebauer ◽  
Andrés Viña ◽  
Sergii Skakun ◽  
Yoshio Inoue
Keyword(s):  
Absorption Coefficient ◽  
Photosynthetically Active Radiation ◽  
Active Radiation ◽  
Photosynthetic Traits

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.

SITE-SPECIFIC EQUATIONS OF STATE FOR COASTAL SEA AREAS AND INLAND WATER BODIES

2017 ◽  
Author(s):  
Natalia Andrulionis ◽  
Natalia Andrulionis ◽  
Ivan Zavialov ◽  
Ivan Zavialov ◽  
Elena Kovaleva ◽  
...  
Keyword(s):  
Equation Of State ◽  
Black Sea ◽  
Water Samples ◽  
Equations Of State ◽  
Sea Water ◽  
Ionic Composition ◽  
Water Bodies ◽  
Aral Sea ◽  
The Black Sea ◽  
Coastal Sea

This article presents a new method of laboratory density determination and construction equations of state for marine waters with various ionic compositions and salinities was developed. The validation of the method was performed using the Ocean Standard Seawater and the UNESCO thermodynamic equation of state (EOS-80). Density measurements of water samples from the Aral Sea, the Black Sea and the Issyk-Kul Lake were performed using a high-precision laboratory density meter. The obtained results were compared with the density values calculated for the considered water samples by the EOS-80 equation. It was shown that difference in ionic composition between Standard Seawater and the considered water bodies results in significant inaccuracies in determination of water density using the EOS-80 equation. Basing on the laboratory measurements of density under various salinity and temperature values we constructed a new equation of state for the Aral Sea and the Black Sea water samples and estimated errors for their coefficients.

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