UV climate over the Southern Ocean south of Australia, and its biological impact - Particulate Organic Carbon (POC) resultsEntry ID: ASAC_2210_POC
Abstract: Minicosm design: Three successive experiments to a maximum incubation of 14 days were performed from mid November to early January in the summer of 2002/03 in a temperature controlled shipping container housing six 500 L polythene tanks or minicosms. Domes of UV transmissive PMMA in the roof of the container directly above the minicosms allowed ambient sunlight to be reflected to the tanks ... through tubes of anodised aluminium. These tubes reflected greater than 96% of the incident radiation irrespective of wavelength.
Light perturbation to each minicosm was achieved by screening materials that attenuated UV wavelengths. UV stabilised polycarbonate removed wavelengths shorter than 400 nm, transmitting only photosynthetically active radiation (PAR) and provided the control treatment (PAR). In minicosm 2, a mylar screen removed UVB wavelengths (280 - 320 nm), providing a treatment (UVA) with PAR and UVA. Minicosms 3, 4 and 5 (UVB1, 2 and 3 respectively) were screened by borosilicate glass of 9, 5, and 3 mm thickness, transmitting ambient light (including UVR) at the equivalent water depths (ED, k=0.4) of 7.15, 5.38 and 4.97 meters respectively. Minicosm 6 (UVB4) was screened with PMMA that transmitted ambient light at an ED of 4.43 m.
Light measurements: Measurements of downwelling UV and PAR were obtained using biometer and Licor sensors mounted on the roof of the minicosm container. A Macam, double grating spectroradiometer measured the spectral irradiance on the roof of the container. This was then weighted with the erythemal action spectrum and correlated to that obtained by the UV biometer. The Macam was used to measure the spectral irradiance at the cross of the UV biometer. The spectral intensity of light wavelengths were measured laterally and vertically in the minicosm screened only by UV-transmissive PMMA irradiance. These measurements were used to model the light field within the minicosm. In all other light treatments the Macam measured the spectral irradiance immediately below the water surface and in the centre of the minicosm. The model was then used to predict the spectral distribution and intensity of other light treatments. These measurements were repeated at interval throughout the season to determine whether solar elevation influenced transmission of ambient downwelling irradiance to the minicosms. UV and PAR sensors fixed to the outside of the minicosm container, together with the modelled light climates within each minicosm beneath each light treatment, predicted the quantify the light to which each experimental treatment was exposed.
This work was conducted as part of ASAC project 2210.
The download file contains three excel spreadsheets, plus three accompanying word documents which provide detailed methods used in the collection of these data, plus more information about the experiments.
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Data Set Citation
Dataset Originator/Creator: Thomson, P.G., Davidson, A.T. and Nunez, M.
Dataset Title: UV climate over the Southern Ocean south of Australia, and its biological impact - Particulate Organic Carbon (POC) results
Dataset Series Name: CAASM Metadata
Dataset Release Date: 2017-08-15
Dataset Publisher: Australian Antarctic Data Centre
Dataset DOI: doi:10.4225/15/5747D14BAAA47Online Resource: https://data.aad.gov.au/aadc/metadata/metadata_redirect.cfm?md=/AMD...
Start Date: 2002-11-15Stop Date: 2003-01-08
Quality See the word documents available in the download for details.
Access Constraints These data are publicly available for download from the provided URL.
Use Constraints This data set conforms to the PICCCBY Attribution License
Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=ASAC_221... when using these data.
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Distribution Size: 450 kb
Distribution Format: Excel, Word
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Creation and Review Dates
DIF Creation Date: 2005-08-11
Last DIF Revision Date: 2017-08-24