Publication
Annual Mixed Layer Carbon Budget for the West Antarctic Peninsula Continental Shelf: Insights From Year‐Round Mooring Measurements
Publisher:
American Geophysical Union (AGU)
Date:
04-2021
DOI:
10.1029/2020JC016920
Abstract: For the first time the annual carbon budget on the West Antarctic Peninsula shelf was studied with continuously measured CO 2 system parameters (pH and p CO 2 ) from a subsurface mooring. The temporal evolution of the mixed layer dissolved inorganic carbon (DIC) is investigated via a mass balance. The annual mixed layer DIC inventory change was 1.1 ± 0.4 mol m −2 yr −1 , which was mainly regulated by biological drawdown (−2.8 ± 2.4 mol m −2 yr −1 ), diapycnal eddy diffusion (2.6 ± 1.3 mol m −2 yr −1 ), entrainment/detrainment (0.9 ± 0.4 mol m −2 yr −1 ), and air‐water gas exchange (0.4 ± 2.1 mol m −2 yr −1 ). Significant carbon drawdown was observed in the spring and summer, which was replenished by the physical processes mentioned above. These observations suggest this area is an annual atmosphere CO 2 sink with a mixed layer net community production of 2.8 ± 2.4 mol m −2 yr −1 . These results highlight the significant seasonality in the DIC mass balance and the necessity of year‐round continuous observations for robust assessments of biogeochemical cycling in this region.