Accession Number:

ADA030900

Title:

A Model of the Spatial Structure and Productivity of Phytoplankton Populations during Variable Upwelling Off the Coast of Oregon

Descriptive Note:

Technical rept.

Corporate Author:

FLORIDA STATE UNIV TALLAHASSEE DEPT OF OCEANOGRAPHY

Personal Author(s):

Report Date:

1976-09-01

Pagination or Media Count:

138.0

Abstract:

During the season favorable for coastal upwelling off the western boundary of continents, the local circulation is strongly influenced by occasional wind events of several days duration. Variability in the wind stress affects the rate of upwelling and ultimately the local biological productivity. To investigate the relationship between wind events and primary production off the coast of Oregon in August 1973, a time-dependent, numerical model of the upwelling circulation was coupled to a complex model of primary and secondary productivity. Primary productivity is a function of nutrient concentration, light intensity and temperature. Advection by a two-cell, upwelling circulation is the major physical mechanism leading to mesoscale patchiness in the phytoplankton, zooplankton, detritus and nutrient fields. The numerical model predicts a phytoplankton and detritus plume for which considerable observational evidence exists. Model predictions of daily primary production during intermittent upwelling are paradoxically comparable to production during strong upwelling. A new formulation for herbivore egestion as a function of food availability is proposed.

Subject Categories:

  • Biological Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE