PRIMARY PRODUCTION IN ANTARCTIC SEA-ICE

A numerical model shows that in Antarctic sea ice, increased flooding in regions with thick snow cover enhances primary production in the in filtration (surface) layer. Productivity in the freeboard (sea level) layer is also determined by sea ice porosity, which varies with temper ature, Spatial and temporal variation in snow thickness and the propor tion of first-year ice thus determine regional differences in sea ice primary production. Model results show that of the 40 teragrams of car bon produced annually in the Antarctic ice pack, 75 percent was associ ated with first-year ice and nearly 50 percent was produced in the Wed dell Sea.