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Carbon cycling dynamics in the seasonal sea‐ice zone of E ast A ntarctica
Author(s) -
Roden Nicholas P.,
Tilbrook Bronte,
Trull Thomas W.,
Virtue Patti,
Williams Guy D.
Publication year - 2016
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1002/2016jc012008
Subject(s) - sea ice , oceanography , biogeochemical cycle , carbon cycle , environmental science , carbon dioxide , antarctic sea ice , climatology , atmosphere (unit) , cryosphere , arctic ice pack , atmospheric sciences , geology , ecosystem , geography , ecology , meteorology , biology
The carbon cycle of the seasonally ice covered region of the southwest Indian Ocean sector of East Antarctica (30°–80°E, 60°–69°S) was investigated during austral summer (January–March 2006). Large variability in the drivers and timing of carbon cycling dynamics were observed and indicated that the study site was a weak net source of carbon dioxide (CO 2 ) to the atmosphere of 0.8 ± 1.6 g C m −2 during the ice‐free period, with narrow bands of CO 2 uptake observed near the continental margin and north of the Southern Antarctic Circumpolar Current Front. Continuous surface measurements of dissolved oxygen and the fugacity of CO 2 were combined with net community production estimates from oxygen/argon ratios to show that surface heat gain and photosynthesis were responsible for the majority of observed surface water variability. On seasonal timescales, winter sea‐ice cover reduced the flux of CO 2 to the atmosphere in the study area, followed by biologically driven drawdown of CO 2 as the ice retreated in spring‐summer highlighting the important role that sea‐ice formation and retreat has on the biogeochemical cycling of the region.