Antarctic Sea Ice nutrients

François Fripiat

In Antarctic sea ice, previous studies reported only punctual measurements of macro-nutrient concentrations, implying that the overall seasonal patterns has remained elusive. Sea ice harbors indeed high spatial and temporal variability (Figure). To overcome such variability, we compiled most of the currently available macro-nutrient data (nitrate, nitrite, ammonium, phosphate, and silicic acid) in Antarctic pack ice. Data come from peer-reviewed publications, cruise reports, and direct contributions by field-research teams. This compilation has been done in the framework of the SCOR (Scientific Committee on Oceanic Research) working group BESPII (Biogeochemical Exchange Processes at Sea Ice Interfaces) and the SCAR (Scientific Committee on Oceanic Research) expert group ASPeCT (Antarctic sea ice processes and climate).

During this seminar, I will discuss about the seasonal pattern of nutrient concentrations in Antarctic sea ice, as well as two interesting findings highlighted by this study. The first one concerns the strong excess in phosphate in Antarctic pack ice in comparison to dissolved inorganic nitrogen. The second concerns nutrient adsorption within sea ice.  These processes are clearly overlooked and open new research questions.