Field Measurement of Light Penetration Through Sea Ice'
ABSTRACT: In connection with phytoplankton studies, a non-optical, non-electric instrument has been devised for the measurement of relative light intensity in sea-ice bore holes. When used with a sensitive photometer, absolute values for the ambient light field can be determined within and immediate...
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| Format: | Text |
| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.500.5170 http://pubs.aina.ucalgary.ca/arctic/Arctic25-1-28.pdf |
| Summary: | ABSTRACT: In connection with phytoplankton studies, a non-optical, non-electric instrument has been devised for the measurement of relative light intensity in sea-ice bore holes. When used with a sensitive photometer, absolute values for the ambient light field can be determined within and immediately under the ice. As anticipated, attenuation is greatest at the ice-air interface; values just below the ice surface were 3 to 20 per cent of incident. Another 70 to 100 cm. of ice was required to effect a further 50 per cent decrease in illumination. Extinction values were also measured on the ice cores in the laboratory, but scattering greatly complicates the interpretation of laboratory results. RÉSUMÉ. Mesures de la pénétration de Za lumière b travers la glace de mer. A l'occasion d'études sur le phytoplancton, les auteurs ont mis au point un instrument non optique et non électrique qui mesure l'intensité lumineuse relative dans des trous forés dans la glace de mer. Avec un photomètre sensible, on peut déterminer des valeurs absolues du champ lumineux ambiant à l'intérieur de la glace et immé-diatement dessous. Comme on l'avait prévu, l'atténuation est la plus grande au plan |
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