Carbonate system and its control factors in the Chukchi Sea in perspective of the changing arctic environment

Abstract

The Arctic Ocean lies in the center of the current climate change as the summer sea-ice extent shrinks dramatically in recent years. Several modeling studies predict complete disappearance of the sea-ice extent in summer this century. One of the concerns resulting from this rapid change in the Arctic climate is the impact on the marine ecosystem in which carbon is the backbone of the energy flow initiated by solar energy. In addition, the shift of the ice-covered to the complete open ocean may lead to the change in the CO2 flux across the sea-surface due to the imbalance in pCO2 between, which is ultimately driven by the primary production in the surface mixed layer and by the Arctic circulation. To investigate the change in the air-sea CO2 flux and the carbonate system interior of the water column, we have visited for 5 years the Chukchi Sea every summer season since 2010 and the Beaufort Sea in 2013 and 2014 onboard the Korean ice breaking R/V Araon. The areas surveyed were always undersaturated with respect to the atmospheric CO2 despite large variability of the degree of saturation. We explored the spatial and temporal characteristics of the carbonate system in conjunction with the extent to which physical and biological properties would influence. To identify the driving forces in changing carbonate system interior of the water column, we focused on the impact of sea-ice melting, freshwater input from the continent, enhanced biological uptake driven by primary production, and chemical processes, which allow us to delve carbon flow in these particular area. In the presentation we will discuss the results from the 5-year observations in the picture of the rapid change in the Arctic environment.