Community Research and Development Information Service - CORDIS


The present study attempts to use the advantages of existing models and methods to evaluate the scales of variation in the vertical distribution of the phytoplankton biomass and the integrated primary production over the North East Atlantic Ocean (5 - 40 N; 6 - 30 W). The choice of this area is dictated principally by its importance to the European economy, and to international oceanographic programmes such as JGOFS. Initially the vertical distribution of chlorophyll is investigated with respect to oceanographic provinces, assuming a Gaussian distribution of chlorophyll with depth in stratified conditions. A comparative study with other models shows significant differences in the biomass profile for chlorophyll values at the surface ranging from 0.05 to 0.5 mg/m3. In a second phase of this work, the biomass relationships are implemented in an existing spectral model to compute the integrated daily rate of photosynthesis in the entire area. Finally, the results are shown in terms of seasonal changes in the daily integrated primary production, including the relative contribution of each bio-province. The effect of upwelling is clearly indicated by high productivity, off the coast of Mauritania, extending offshore due to a peculiar system of surface currents in this area. In the open ocean, primary production remains weaker by one order of magnitude when compared to coastal zones. Annual and seasonal values of primary production are also given and discussed in comparison with values proposed for the entire North Atlantic basin.

Additional information

Authors: HÖPFFNER N, JRC Ispra (IT);STURM B, JRC Ispra (IT);LARKIN D, DJL Software Consultancy Ltd., Jarrow (GB)
Bibliographic Reference: Paper presented: JGOFS, Villefranche-sur-Mer (FR), May 8-12, 1995
Availability: Available from (1) as Paper EN 38965 ORA
Record Number: 199510698 / Last updated on: 1995-07-07
Original language: en
Available languages: en