Investigation of Bio-Physical Coupling in the Seasonal Ice Zone (BiPhyCoSi)
Final Report Abstract
The pelagic province of the Southern Ocean generally has low levels of primary production attributable to a short growing season in the higher latitudes, a deep mixed layer, and iron limitation. Exceptions include phytoplankton blooms in the marginal ice zone (MIZ) during spring and summer sea ice retreat. The prevailing hypothesis as to the drivers of the blooms is that sea ice retreat increases the vertical stability of the water column through the production of melt water and provides shelter from windmixing in areas of partial sea ice coverage. These conditions are favourable to phytoplankton growth by allowing them to maintain their position in the upper layers of the water column. This work investigates the drivers of MIZ blooms using a biogeo(?)chemically-coupled global circulation model. Results support the hypothesis in that physical conditions related to a shallow, vertically stable water column (e.g. mixed layer depth and available light) were the most significant predictors of bloom dynamics, while nutrient limitation was of lesser importance. We estimate that MIZ blooms account for 15% of yearly net primary production in the Southern Ocean and that the earlier phases of the MIZ bloom, occurring under partial ice coverage and invisible to remote sensing, account for about two-thirds of this production. MIZ blooms were not found to enhance depth-integrated net primary production when compared to similar ecological provinces outside of the MIZ, although the elevated phytoplankton concentrations in surface waters are hypothesised to provide important feeding habitats for grazing organisms, such as krill. Additionally, research carried out within BiCoPhySI led to improved statistical exploration of the linking of physical and biological processes in collaboration with national and international partner-institutions, but also included the development of new statistical approaches, which may have applications in the use of remote sensing data.
Publications
- (2010). On the formulation of sea-ice models. Part 1: Effects of different solver implementations and parameterizations. Ocean Modelling, 33, 129-144
Losch, M., D. Menemenlis, J.-M. Campin, P. Heimbach, C. Hill
(See online at https://doi.org/10.1016/j.ocemod.2009.12.008) - (2011), Bio-optical provinces in the eastern Atlantic Ocean and their biogeographical relevance. Biogeosciences, 8, 3609–3629
Taylor, B. B., E. Torrecilla, A. Bernhardt, M. H. Taylor, I. Peeken, R. Röttgers, J. Piera, and A. Bracher
(See online at https://doi.org/10.5194/bg-8-3609-2011) - (2012), El Niño induced changes to the Bolivar Channel ecosystem (Galapagos): comparing model simulations with historical biomass time series, Mar. Ecol. Prog. Ser., Vol. 448: 7–22
Wolff, M., D. J. Ruiz, M Taylor
(See online at https://doi.org/10.3354/meps09542) - (2013), Estimation of relative phycoerythrin concentrations from hyperspectral underwater radiance measurements - a statistical approach. J. Geophys. Res. Oceans
Taylor, B. B., M. H. Taylor, T. Dinter, A. Bracher
(See online at https://doi.org/10.1002/jgrc.20201) - (2013), On the drivers of phytoplankton blooms in the Antarctic marginal ice zone: A modeling approach, J. Geophys. Res. Oceans, 118, 63–75
Taylor, M. H., M. Losch, and A. Bracher
(See online at https://doi.org/10.1029/2012JC008418)
