The main objectives of OMEX II-II are the construction and understanding of the carbon cycle and its associated elements along the Iberian margin. This area is dominated by wind driven upwelling events during the summer, and by ria inputs and downwelling during the winter. Coastal upwelling areas are among the most productive biological systems in the ocean and therefore of particular economical interest. They are also characterized by large fluxes of organic carbon, nutrients and other trace elements which may be exported to the open ocean or rapidly deposited and buried at geological time scales. They are thus playing an essential role in the marine biogeochemical cycle of many elements.
The study of the physical processes should provide knowledge of the local factors (wind and topography) affecting horizontal and vertical transport in relation to the general circulation. Special attention will be devoted to the role of filaments and eddies in the exchange of material between the coastal zone and the open ocean.
Short time scale measurements of flows of carbon and nutrients through the food web will be performed during upwelling events and occasionally in the winter during periods of downwelling. On the other hand, spatial and seasonal variations of the inventories and fluxes of the carbon and associated elements will be investigated to obtain a mass balance of organic matter in the water column in the investigated area.
Since a large part of the primary production in the coastal upwelling zones is rapidly deposited, a special attention will be brought to the understanding, quantification and modelling of the benthic processes related to biological activity and early diagenesis.
A better knowledge of the carbon fluxes and budgets will improve our evaluation of the role of upwelling in organic carbon production and fate in the marine system. This study may refine our understanding of the effect of coastal upwelling on the global climate control and vice versa of potential effects of global warming on the upwelling processes.
Six OMEX cruises were carried out by the Unit:Aboard the R. V. Belgica (Belgium, cruise 9714), from 18th June to 2nd July 1997:
Aboard the Charles
Darwin (United Kingdom, cruise CD110-B), from 6th to 19th
- Underway subsurface measurements during the whole cruise of pCO2 & pH(SWS)
- Niskin sampling at 7 stations and 58 depths for the determination of total alkalinity, pH(SWS) & dissolved oxygen
Aboard the R.
V. Belgica (Belgium, cruise 9815), from 27th June to 7th
- Underway subsurface measurements during the whole cruise of pCO2, pH(SWS) & dissolved oxygen
- CTD at 51 stations and Niskin sampling at 236 depths for the determination of total alkalinity, pH(SWS), chlorophyll, dissolved oxygen & plankton speciation.
Aboard the Charles
Darwin (United Kingdom, cruise CD114 A-B), from 29th July
to 24th August 1998:
- Underway subsurface measurements during the whole cruise of pCO2, dissolved O2 & pH(SWS)
- Niskin sampling at 33 stations and 229 depths for the determination of Total Alkalinity, pH(SWS) & dissolved oxygen
Aboard the R.
V. Belgica (Belgium, cruise 9919), from 30th August to
21st September 1999:
- Underway subsurface measurements during the whole cruise of pCO2, pH(SWS)& dissolved oxygen
- CTD at 34 stations and Niskin sampling at 351 depths for the determination of total alkalinity, pH(SWS) & dissolved oxygen.
OMEX related publications by the Unit:
Borges A.V. and Frankignoulle M. (2003) Distribution of surface carbon dioxide and air-sea exchange in the English Channel and adjacent areas. Journal of Geophysical Research, 108(C5), doi: 10.1029/2000JC000571.
Alvarez-Salgado X.A., F.G. Figueiras, F.F. Pérez , S. Groom, E. Nogueira, A.V. Borges, L. Chou, C.G. Castro, G. Moncoiffe, A.F. Rios, A.E.J. Miller, M. Frankignoulle, G. Savidge and Wollast R. (2003) The Portugal coastal counter current off NW Spain: new insights on its biogeochemical variability. Progress in Oceanography, 56(2), 281-321.
Borges A. V. and Frankignoulle M. (2002) Aspects of dissolved inorganic carbon dynamics in the upwelling system off the Galician coast.Journal of Marine Systems, 32, 181-198.
Borges A.V. and Frankignoulle M. (2002) Distribution of surface carbon dioxide and air-sea exchange in the upwelling system off the Galician coast . Global Biogeochemical Cycles, 16, 4-1, 4-14.
Borges A. V. and Frankignoulle M. (2001) Short-term variations of the partial pressure of CO2 in surface waters of the Galician upwelling system. Progress in Oceanography, 51(2-4), 283-302.
Álvarez-Salgado X.A., M.D. Doval, A. V. Borges, I. Joint, M. Frankignoulle, E.M.S. Woodward and Figueiras F.G. (2001) Off-Shelf Fluxes of Labile Materials by an Upwelling Filament in the NW Iberian Upwelling System. Progress in Oceanography, 51(2-4), 321-337.
Frankignoulle M. and Borges A.V. (2001) European continental shelf as a significant sink for atmospheric carbon dioxide. Global Biogeochemical Cycles, 15(3), 569-576.
Keir R.S., G. Rehder, Frankignoulle M. (2001) Partial pressure and air-sea flux of CO2 in the Northeast Atlantic during September 1995. Deep Sea Research II, 48, 3179-3189.
Frankignoulle M., Bourge I., Canon C. and Dauby P. (1996) Distribution of surface seawater partial CO2 pressure in the English Channel and in the Southern Bight of the North Sea. Continental Shelf Research, 16 , 381-395.
Frankignoulle M., Elskens M., Biondo R., Bourge I., Canon C., Desgain S. and Dauby P. (1996) Distribution of inorganic carbon and related parameters in surface seawater of the English Channel in Spring 1994. Journal of Marine Systems, 7(2-4), 427-434.