Premium
Dissolved inorganic carbon dynamics and air‐sea carbon dioxide fluxes during coccolithophore blooms in the northwest European continental margin (northern Bay of Biscay)
Author(s) -
Suykens K.,
Delille B.,
Chou L.,
De Bodt C.,
Harlay J.,
Borges A. V.
Publication year - 2010
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2009gb003730
Subject(s) - coccolithophore , emiliania huxleyi , oceanography , bay , phytoplankton , dissolved organic carbon , ocean acidification , bloom , sink (geography) , salinity , alkalinity , total inorganic carbon , carbon dioxide , environmental science , seawater , algal bloom , carbon sink , pelagic zone , geology , chemistry , climate change , nutrient , cartography , organic chemistry , geography
We report a data set of dissolved inorganic carbon (DIC) obtained during three cruises in the northern Bay of Biscay carried out in June 2006, May 2007, and May 2008. During these cruises, blooms of the coccolithophore Emiliania huxleyi occurred, as indicated by patches of high reflectance on remote sensing images, phytoplankton pigment signatures, and microscopic examinations. Total alkalinity showed a nonconservative behavior as a function of salinity due to the cumulative effect of net community calcification (NCC) on seawater carbonate chemistry during bloom development. The cumulative effect of NCC and net community production (NCP) on DIC and the partial pressure of CO 2 (pCO 2 ) were evaluated. The decrease of DIC (and increase of pCO 2 ) due to NCC was overwhelmingly lower than the decrease of DIC (and decrease of pCO 2 ) due to NCP (NCC:NCP ≪ 1). During the cruises, the northern Bay of Biscay acted as a sink of atmospheric CO 2 (on average ∼−9.7 mmol C m −2 d −1 for the three cruises). The overall effect of NCC in decreasing the CO 2 sink during the cruises was low (on average ∼12% of total air‐sea CO 2 flux). If this is a general feature in naturally occurring phytoplankton blooms in the North Atlantic Ocean (where blooms of coccolithophores are the most intense and recurrent), and in the global ocean, then the potential feedback on increasing atmospheric CO 2 of the projected decrease of pelagic calcification due to thermodynamic CO 2 “production” from calcification is probably minor compared to potential feedbacks related to changes of NCP.