Phytoplankton bloom in the Gulf of Elat/Aqaba: physical vs. ecological
forcing
Abstract
Phytoplankton bloom in the Gulf of Elat/Aqaba was studied before mainly
using one-dimensional models and observations from the northern Gulf.
Thus, the spatial variability within the Gulf and the contribution of
physical processes such as horizontal advection to the bloom have not
yet been studied. Moreover, various factors such as light limitation are
still debated. Here we used a three-dimensional coupled
physical-ecological model for the Gulf of Elat/Aqaba to study the
mechanisms for phytoplankton bloom throughout the Gulf. We found the
southern surface bloom to be higher than the northern surface. In
contrast, southern integrated bloom is lower than the northern bloom.
These differences are due to spatial variations in the mixed layer
depth, which
is much deeper in the northern Gulf compared with the south. Moreover,
horizontal advection controls phytoplankton integrated biomass during
the bloom, a process often neglected when dealing with phytoplankton
blooms. Finally, we found that light limits growth of the northern
integrated bloom.