Productivity in tropical upwelling areas considered by a new method of analysis and determination.

• Main Authors: Minas, H, Minas, M, Packard, T
• Format: Conference Object
• Language: English
• Published: Actes de colloques. Ifremer. Brest [ACTES COLLOQ. IFREMER.]. 1984 1984
• Subjects: Primary production; Dynamical oceanography; T/S diagrams; Fertility; Biomass; Upwelling; Pelagic environment; Analytical techniques; Biological production; Pacific; North Atlantic
• Online Access: https://archimer.ifremer.fr/doc/1984/acte-1527.pdf; https://archimer.ifremer.fr/doc/00000/1527/

When in frontal zones of upwelling areas, a two-component mixing of nutrient rich upwelled water and oligotrophic offshore waters occurs, the amounts of nutrient consumed (- Delta N) and oxygen produced (+ Delta O2) can be evaluated by a detailed analysis of diagrams, in which salinity is the conservative parameter. By this same method, the corresponding T-S diagram allows a determination of the net heat gain of the upwelling water body during its offshore transport, and consequently the corresponding residence time in the photic zone. By integrating the nutrient consumption over the whole upwelling area, it is possible to obtain a more realistic average value of the productivity than with direct measurements of photosynthetic activity (14C and other incubation methods). The Pacific Ocean upwellings are richer, and within the Atlantic Ocean, the nutrient richer SACW in regard to the NACW (south and North Atlantic Central Waters) explains greater carbon budgets in the concerned upwelling zones.