A simulated Antarctic ast ice ecosystem

摘要: A simple two-dimensional (z,t) model of first year sea ice structure and dynamics is coupled to a high resolution, time-dependent microalgal growth in which simulated physiological responses are determined by ambient temperature, spectral irradiance, nutrient concentration, salinity. The physical component utilizes atmospheric data simulate congelation growth, initial brine entrapment, desalination, flux. Temperature gradient, salinity, volume also computed. biological based on the concept maximum temperature-dependent algal rate reduced limitations imposed from insufficient light or nutrients, as well suboptimal Estimated gross primary productivity respiration grazing terms. Preliminary simulations indicate that, during bloom, microalgae able maintain their vertical position relative lower margin not incorporated into crystal matrix sheet thickens. Model results imply that land fast contains numerous microhabitats functionally distinct upon unique suite processes control accumulation within each. In early stages spring salinity inhibits at all depths ice, except near skeletal layer. Light predicted be limiting resource throughout platelet this time. Later bloom when environmental conditions more favorable for suggest biomass upper controlled microzooplankton grazing, Microalgae layer susceptible limitation time due diminished flux demand. limits bloom. Results McMurdo Sound can support production approximately 0.5 g C m−2 d−1 under optimal conditions, 76% associated with where rates exchange relatively high. While adjustments any coefficient will alter magnitude model, range permitted uncertainty values bounds likely result normal variations snow cover,