Antarctic pack ice algal distribution: Floe-scale spatial variability and predictability from physical parameters

• Published in: Geophysical Research Letters
• Main Authors: Meiners, K. M., Arndt, S., Bestley, S., Krumpen, T., Ricker, R., Milnes, M., Newbery, K., Freier, U., Jarman, S., King, R., Proud, R., Kawaguchi, S., Meyer, B.
• Other Authors: Laboratoire d'Océanographie Physique et Spatiale (LOPS), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2017
• Subjects: sea ice properties; snow; freeboard; chlorophyll a; ice algae; biomass; [SDU]Sciences of the Universe [physics]; Antarctic; Southern Ocean; Weddell; Weddell Sea; Antarc*; Sea ice
• Online Access: https://insu.hal.science/insu-03682743; https://insu.hal.science/insu-03682743/document; https://insu.hal.science/insu-03682743/file/Geophysical%20Research%20Letters%20-%202017%20-%20Meiners%20-%20Antarctic%20pack%20ice%20algal%20distribution%20Floe%25u2010scale%20spatial%20variability%20and.pdf; https://doi.org/10.1002/2017GL074346

International audience Antarctic pack ice serves as habitat for microalgae which contribute to Southern Ocean primary production and serve as important food source for pelagic herbivores. Ice algal biomass is highly patchy and remains severely undersampled by classical methods such as spatially restricted ice coring surveys. Here we provide an unprecedented view of ice algal biomass distribution, mapped (as chlorophyll a) in a 100 m by 100 m area of a Weddell Sea pack ice floe, using under-ice irradiance measurements taken with an instrumented remotely operated vehicle. We identified significant correlations (p < 0.001) between algal biomass and concomitant in situ surface measurements of snow depth, ice thickness, and estimated sea ice freeboard levels using a statistical model. The model's explanatory power (r 2 = 0.30) indicates that these parameters alone may provide a first basis for spatial prediction of ice algal biomass, but parameterization of additional determinants is needed to inform more robust upscaling efforts.