Fall dynamics of the carbonate system in the shallow Chukchi Sea is a result of the interaction between physical and biological processes such as mixing of different water masses, cooling, photosynthesis-respiration. The study area acts as a sink for atmospheric CO₂. The general trend in surface pCO₂ distribution is a decrease towards the ice edge, which is determined by the temperature decrease, whereas mesoscale variability of the carbonate parameters is controlled by the interaction between different waters. The calculated September 1996 flux of CO₂ from the air into the sea on eastern Chukchi Sea is about 1×10¹² g C.