Investigation of Bio-Physical Coupling in the Seasonal Ice Zone (BiPhyCoSi)

The Antarctic seasonal ice zone (SIZ) has been found to support spring phytoplankton blooms orders of magnitude more intense than growth in neighbouring open ocean waters. These blooms support a large portion of the annual growth at higher trophic levels, they contribute to sedimentation of particulate carbon into deep ocean layers, and their timing is crucial for prey organisms such as zooplankton. However, SIZ blooms may not be repeatable, with blooms sometimes not detected at all.

Current methods for assessing SIZ bloom activity are limited to shipboard sampling, with obvious logistical constraints, and satellite remote sensing, which can only detect the edges of the bloom where ice concentrations have fallen to zero. This leaves ocean modelling as the only means of examining aspects of SIZ blooms over large areas and over the full growth period.

This study will use a coupled ocean-ice-ecosystem model to provide the first estimates of bloom magnitude and dynamics. Specifically, the study will assess: 1) the relative importance of wind, sea-ice history and insolation; 2) the inter-annual variability in geographical extent and intensity of SIZ blooms over the last 10 years; 3) the amount and variability of biomass rendered invisible to satellites by the presence of sea-ice.





Figures above: 2006 and 2007 Model results. Surface chlorophyll as concentration (color) and ice concentration (contour lines) on Nov 19, 2006 (top) and Nov 19, 2007 (bottom)

Scientists

Martin Losch
Astrid Bracher
Marc Taylor
Alfred-Wegener-Institute for Polar and Marine Research
Bremerhaven

Research areas

Marginal Ice Zone around the Antarctic Continent

Publications

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Homepage

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Research funding organisation

German Research Foundation

Project number: LO-1143/6
Funding period: November 2009 – October 2012