Abstract:
Due to current patterns and heavy nutrient loads from rivers, phytoplankton
production rates can cause algal blooms. Since earth observation delivers a synoptic
view of the ocean, together spatially and temporally, satellite ocean colour sensors'
data are broadly used for exposure, mapping and monitoring of these blooms.
Therefore, the research was focused on validating a phytoplankton model from the
images derived fromSeaDAS software using chlorophyll-a algorithm.
Here in-situ (cruise) data were compared with daily satellite image data obtained
from NASA ocean colour website with 4km resolution and a sensor with least error
was selected. Then monthly chlorophyll concentrations retrieved from Indian
Ocean using MODIS (Moderate Resolution Imaging Spectroradiometer) Aqua
sensor for the period of 2009-January to 2016-September were analysed and
selected a bloom effect region as a geo location and particular time period that
occurred. Also certain parameters which caused that were identified such as ocean
nutrients, currents and wind.
The obtained information indicated that despite the normal low chlorophyll
concentration (0.01 -0.1 mgm’3) in these oligotrophic waters, there is a characteristic
seasonal bloom in June-August on the South-West coast of India and in South coast
of Sri Lanka concurrent with summer monsoon currents and winds.