Skip to main content
padlock icon - secure page this page is secure

Free Content Phytoplankton seasonal distribution from SeaWiFS data in the Agulhas Current system

Download Article:
The interocean conduit for warm Indian Ocean water into the Atlantic Ocean is the Agulhas system which plays an important role in maintaining the global thermohaline circulation. The frontal system formed by the Agulhas Return Current (ARC) and the Subtropical Convergence (STC) is also a region of intense mesoscale activity presenting enhanced levels of biological production and chlorophyll a. We jointly analyzed three different satellite data sets to relate the remotely sensed distribution of phytoplankton (SeaWiFS ocean color data) to the dynamical environment (Topex/Poséidon-ERS sea level anomalies-SLA- and sea-surface temperature-SST-) to gain insight into the seasonal behavior of the Agulhas Current system. We used a wavelet analysis to retrieve the characteristic wavelengths of the ARC and STC associated to their meandering. By meridionally averaging (between 15- 45E) the two-dimensional power Hovmöller of each signal (Chla, SLA, and SST), we obtained a seasonal average variance for Chla, SLA and SST as a function of latitude. Within the double frontal Agulhas and Subtropical frontal system, an extended temporal maximum in chlorophyll a concentration is observed in spring-summer-fall and a well-marked minimum occurs in winter, in phase opposition with the southwest Indian Ocean subtropical gyre north of the frontal system. Seasonal changes in strength of cross-frontal mixing with the subtropical gyre, in density strength of the juxtaposed fronts, and in mixed-layer depth and light availability seem the most likely explanations for the observed spatial and seasonal variability of the chlorophyll a distribution.

30 References.

No Supplementary Data.
No Article Media
No Metrics

Document Type: Research Article

Publication date: September 1, 2001

More about this publication?
  • The Journal of Marine Research, one of the oldest journals in American marine science, publishes peer-reviewed research articles covering a broad array of topics in physical, biological and chemical oceanography. Articles that deal with processes, as well as those that report significant observations, are welcome. Biological studies involving coupling between ecological and physical processes are preferred over those that report systematics. The editors strive always to serve authors and readers in the academic oceanographic community by publishing papers vital to the marine research in the long and rich tradition of the Sears Foundation for Marine Research. We welcome you to the Journal of Marine Research.
  • Editorial Board
  • Information for Authors
  • Subscribe to this Title
  • Purchase The Sea
  • Ingenta Connect is not responsible for the content or availability of external websites
  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more