Effects of sea-ice light attenuation and CDOM absorption in the water below the Eurasian sector of central Arctic Ocean (>88°N)

Polar research

Stiig Markager²  Brian K. Sorrell⁴  Lars Chresten Lund-Hansen⁵  Hans Ramløv⁶  Søren Rysgaard⁸  Kasper Hancke⁹  Tanja Stratmann^1,10 

[1] Arctic Research CenterAarhus University, C.F. Møllers Allé 8, Building 1110, DK-8000 Aarhus C, Denmark;Arctic Research CenterAarhus University, C.F. Møllers Allé 8, Building 1110, DK-8000 Aarhus C, DenmarkCorrespondence;Centre for Earth Observation ScienceDepartment of Environment and Geography, University of Manitoba, Winnipeg MB R3T 2N2, Canada;Greenland Climate Research Centre, c/o Greenland Institute of Natural Resources, DK-3900 Nuuk Greenland, Denmark;Aquatic BiologyDepartment of Bioscience, Aarhus University, Ole Worms Allé 1, Building 1134, DK-8000 Aarhus C, Denmark;Arctic Research CenterAarhus University, C.F. Møllers Allé 8, Building 1110, DK-8000 Aarhus C, Denmark;Department of ScienceSystems and Models, Roskilde University, Universitetsvej 1, DK-4000 Roskilde, Denmark;Ecosystem StudiesRoyal Netherlands Institute for Sea Research, Korringaweg 7, NL-4401 NT Yerseke, The Netherlands;Marine EcologyDepartment of Bioscience, Aarhus University, Frederiksborgvej 399, DK-4000 Roskilde, Denmark;Nordic Centre for Earth EvolutionDepartment of Biology, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark

关键词: Sea ice;    transmittance;    PAR;    CDOM;    chl-a;    Eurasian sector.;   

DOI  :  10.3402/polar.v34.23978

学科分类：自然科学（综合）

来源: Co-Action Publishing

【 摘 要 】

This is a study of the optical, physical and biological parameters of sea ice and the water below it at stations (n=25) in the central (>88°N) Eurasian sector of the Arctic Ocean during the summer 2012 record low sea-ice minimum extent. Results show that photosynthetically active radiation (PAR) transmittance of the ice was low (0.09) and apparently related to a high degree of backscattering by air-filled brine channels left by brine draining. The under-ice PAR was also low (8.4±4.5 SD µmol photons m−2 s−1) and partly related to the low transmittance. There were no significant differences in multi-year and first-year PAR transmittances. In spite of this low under-ice PAR, only 3% of the transmitted PAR through the ice was absorbed by phytoplankton in the water. On average, chlorophyll-a concentrations were low (0.34±0.69 SD mg chl-a m−3) in the water compared to the high (a 375=0.52 m−1) coloured dissolved organic matter (CDOM) absorption coefficient with a strong terrestrial optical signature. Two distin...

【 授权许可】

CC BY-NC