Dynamics of nutrients, dissolved organic matter and exopolymers in sea ice

Sea ice provides a seasonal to multi-year dynamic reservoir for particulates and solutes, and supports various ecosystem processes that drive polar marine biogeochemistry. Initial concentrations of solutes in sea ice are generally controlled by the composition of the water from which the sea ice forms. Subsequently, solute pools are modified by boundary fluxes and also cycled within the ice due to chemical and biological transformations. This chapter provides an overview of the current understanding of the sources and sinks of biologically important inorganic and organic solutes in sea ice. The focus is on coupled physical, chemical and biological processes that influence the pools of dissolved inorganic macronutrients (nitrate, nitrite, ammonium, phosphate, silicic acid), the micronutrient iron and dissolved organic matter in sea ice. Additionally, the dynamics of sea ice exopolymers including exopolymeric gels and particles are discussed.