Ocean-atmosphere exchange of organic carbon and CO2 surrounding the Antarctic Peninsula

• Published in: Biogeosciences
• Main Authors: Ruiz-Halpern, Sergio, Calleja, Maria Ll., Dachs, Jordi, Vento, Sabino del, Pastor, Marcos, Palmer, Miquel, Agustí, Susana, Duarte, Carlos M.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: European Geosciences Union 2014
• Subjects: Solar radiation; Dissolved organic carbon; Crustacean; Chlorophylla; Carbon dioxide; Carbon budgets; Atmosphere-ocean coupling; Antarctic; Antarctic Peninsula; Austral; The Antarctic; Antarc*; International Polar Year; IPY
• Online Access: http://hdl.handle.net/10261/99455; https://doi.org/10.5194/bg-11-2755-2014

Exchangeable organic carbon (OC) dynamics and CO2 fluxes in the Antarctic Peninsula during austral summer were highly variable, but the region appeared to be a net sink for OC and nearly in balance for CO2. Surface exchangeable dissolved organic carbon (EDOC) measurements had a 43±3 (standard error, hereafter SE) μmol CL-1 overall mean and represented around 66% of surface non-purgeable dissolved organic carbon (DOC) in Antarctic waters, while the mean concentration of the gaseous fraction of organic carbon (GOCH′-1) was 46±3 SE μmol C L -1. There was a tendency towards low fugacity of dissolved CO 2 (fCO2-w) in waters with high chlorophyll a (Chl a) content and high fCO2-w in areas with high krill densities. However, such relationships were not found for EDOC. The depth profiles of EDOC were also quite variable and occasionally followed Chl a profiles. The diel cycles of EDOC showed two distinct peaks, in the middle of the day and the middle of the short austral dark period, concurrent with solar radiation maxima and krill night migration patterns. However, no evident diel pattern for GOC H′-1 or CO2 was observed. The pool of exchangeable OC is an important and active compartment of the carbon budget surrounding the Antarctic Peninsula and adds to previous studies highlighting its importance in the redistribution of carbon in marine environments. © Author(s) 2014. This is a contribution of both Aportes Atmosféricos de Carbono Orgánico y Contaminanates al océano Polar (ATOS) and the Spanish component of the Synoptic Antarctic Shelf-Slope Interactions study (ESASSI), funded by the Spanish Ministry of Science under the scope of the International Polar Year (IPY). Maria Ll. Calleja was funded by the Spanish Research Council (CSIC, grant JAEDOC030) and cofounded by the Fondo Social Europeo (FSO) Peer Reviewed