Using a three-dimensional coupled physical-biological model, this paper
explores the creation of phytoplankton blooms around tropical islands in
the presence of ambient currents and short-lived (~4
days) wind events. The ambient flow creates a retention zone of weak
flows in the lee of the island, which is a typical feature of island
wakes. Findings reveal that wind-induced upwelling effects are essential
for the initial nutrient enrichment and phytoplankton growth that occur
mainly in this retention zone. Oscillating flow, typical of island
wakes, occasionally releases mesoscale patches of upwelled water and its
phytoplankton load into the ambient ocean. The phytoplankton continues
to grow within floating structures that are of up to 20 km in diameter.
This mechanism complements the plankton growth associated with the
formation of mesoscale eddies.