|Title||Modeling the recent changes in the Arctic Ocean CO2 sink (2006-2013)|
|Publication Type||Journal Article|
|Year of Publication||2019|
|Authors||Manizza M, Menemenlis D., Zhang H, Miller C.E|
|Journal||Global Biogeochemical Cycles|
|Type of Article||Article|
|Keywords||atmospheric carbon-dioxide; Environmental Sciences & Ecology; fluxes; Geology; greenland sea; impact; marine; Meteorology & Atmospheric; sciences; sea-ice; Shelf; uptake capacity; variability; wind-speed|
The Arctic Ocean (AO) and its associated marginal seas have recently experienced rapid climate and environmental changes, most notably sea-ice area (SIA) loss and warming potentially impacting its uptake of carbon dioxide (CO2). We used the state-of-the-art ECCO2-Darwin coupled ocean-biogeochemistry model to simulate the 2006-2013 period and investigate the impact of changing SIA on the CO2 uptake of the AO. We find that the mean annual CO2 sink of the AO is 153 +/- 14 TgC a(-1) and the CO2 sink decreased at a rate of 3.6 TgC a(-1) even though SIA decreased by 8 x 10(4) km(2) a(-1) over the same period. Extreme SIA loss in 2007 resulted in a 185.4 TgC CO2 sink, an increase similar to 20% over the 2006-2013 mean. In contrast, extreme SIA loss of 2012 resulted in a CO2 sink of the AO of only 146.3 TgC due to two main factors: (1) increased both wind speed and stratification in the Eastern Siberian Sea absorbing less CO2 and (2) decreased primary production and area of air-sea gas exchange in the Chukchi and Nordic Seas. Our model captures a trend of decreasing CO2 sink in most of the Chukchi Sea during fall but does not show the changes in winter CO2 sink in the Nordic and Barents Seas as previous independent studies have suggested. Our results indicate that future AO-atmosphere CO2 exchange will be determined by complex interplay of SIA and other environmental drivers.