Articles | Volume 11, issue 10
Biogeosciences, 11, 2755–2770, 2014
Biogeosciences, 11, 2755–2770, 2014

Research article 26 May 2014

Research article | 26 May 2014

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

S. Ruiz-Halpern1,7, M. Ll. Calleja2, J. Dachs3, S. Del Vento4,3, M. Pastor5, M. Palmer1, S. Agustí6,1, and C. M. Duarte6,1 S. Ruiz-Halpern et al.
  • 1Instituto Mediterráneo de Estudios Avanzados (IMEDEA), Consejo Superior de Investigaciones Científicas-Universitat de les Illes Balears (CSIC-UIB), Esporles, I. Balears, Spain
  • 2Instituto Andaluz de Ciencias de la Tierra (IACT), Consejo Superior de Investigaciones Científicas – Universidad de Granada (CSIC-UGR), Avda. de las Palmeras 4, 18100 Armilla, Granada, Andalusia, Spain
  • 3Department of Environmental Chemistry, Institute of Environmental Assessment and Water Research (IDAEA), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Catalonia, Spain
  • 4Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
  • 5Departamento de Acústica y Geofísica Unidad de Tecnología Marina-Consejo Superior de Investigaciones Científicas (UTM-CSIC), Barcelona, Catalonia, Spain
  • 6The UWA Oceans Institute and School of Plant Biology, University of Western Australia, 35 Stirling Highway, Crawley 6009, Australia
  • 7Centre for Coastal Biogeochemistry, School of Environment, Science and Engineering, Southern Cross University, Lismore, New South Wales, Australia

Abstract. 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 C L−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 (GOC H–1) was 46 ± 3 SE μmol C L−1. There was a tendency towards low fugacity of dissolved CO2 (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.

Final-revised paper