Arctic Sea Ice Loss Amplifies Decadal CO2 Increase
We use several decades of observations and model results to reveal the underlining mechanism of CO2 increase due to warming and declining sea ice.
The Arctic Ocean has been considered a potentially large sink of anthropogenic CO2, but biophysical environment changes have led to quick loss of capacity in the Canada Basin.
Arctic Ocean sea-ice loss, a critical consequence of climate change associated with a fresher and isolated surface mixed layer, serves as an amplifier of the seasonal variation and decadal increase of pCO2pCO2 in the Canada Basin. In contrast to the thermal and biophysical effects that dominate the pCO2 seasonal cycles in the low and mid-latitudes, the subarctic seas, and most of the Southern Ocean, the sea-ice melt cycle in the Arctic Ocean operates as a unique mechanism and magnifies changes in pCO2 over seasonal to decadal scales. The accelerated sea-ice loss anticipated in the near future will increase seasonal variations in sea surface pCO2, decrease the CO2 sink in the Canada Basin and increase it on the Chukchi Shelf, and increase the long-term ocean acidification rates in the Arctic Ocean, which may profoundly affect the carbon cycle, biogeochemical dynamics, and ecosystem functions.