Arabian Sea eddies promote seasonal phytoplankton blooms



In the Arabian Sea, two phytoplankton blooming periods occur each year, one during the winter northeast monsoon and one during the summer southwest monsoon. It has been established that on the large scale the spatial distribution of the seasonal blooms is driven by mesoscale structures, including eddies and filaments, but studies have not resolved the details linking the physical and biogeochemical processes involved. To improve understanding of mechanisms regulating blooms, Resplandy et al. studied the mesoscale process contribution to nutrient transport using a high-resolution physical circulation model. The model reproduces the seasonal phytoplankton blooms and shows how physical mesoscale processes such as eddies bring increased nutrient supply to the upper layer of the sea during monsoon seasons, thus promoting the growth of phytoplankton blooms twice a year. (Journal of Geophysical Research-Oceans, doi:10.1029/2011JC007006, 2011)