Build-up and decline of organic matter during PeECE III

K. G. Schulz (1) , U. Riebesell (1) , R. G. J. Bellerby (2, 3) , H. Biswas (1) , M. Meyerhöfer (1) , M. N. Müller (1) , J. K. Egge (4) , J. C. Nejstgaard (4) , C. Neill (2) , J. Wohlers (1) , E. Zöllner (1)

1 IFM-GEOMAR - Leibniz-Institut für Meereswissenschaften
2 BCCR - Bjerknes Centre for Climate Research
3 GFI / BiU - Geophysical Institute [Bergen]
4 UiB - University of Bergen

Increasing atmospheric carbon dioxide (CO₂) concentrations due to anthropogenic fossil fuel combustion currently change the ocean's chemistry. Increasing oceanic [CO₂] and subsequent decreasing seawater pH have the potential to significantly impact marine life. Here we describe and analyze the build-up and decline of a natural phytoplankton bloom initiated during the 2005 mesocosm Pelagic Ecosystem CO₂ Enrichment study (PeECE III). We show that processes of inorganic carbon uptake in mixed surface waters and organic carbon export to depth were significantly enhanced at elevated CO₂, while ammonium regeneration in deep waters was substantially reduced. This has important implications for our understanding of pelagic ecosystem functioning and future carbon cycling.

Domaines: Cosmologie et astrophysique extra-galactique [astro-ph.CO]; Astrophysique [astro-ph]; Interfaces continentales, environnement; Océan, Atmosphère; Sciences de la Terre

K. G. Schulz, U. Riebesell, R. G. J. Bellerby, H. Biswas, M. Meyerhöfer, et al.. Build-up and decline of organic matter during PeECE III. Biogeosciences Discussions, 2007, 4 (6), pp.4539-4570. ⟨hal-00297950⟩