LAUSR

Fluorescence line height (FLH) is a relative measure of the amount of radiance leaving the sea surface in the chlorophyll fluorescence emission band. Satellite-derived FLH images provide information about the surface chlorophyll distribution which in turn can be used for monitoring surface phytoplankton blooms in coastal waters. The present study aims at observing a phytoplankton bloom in the Kakinada coastal waters along the east coast of India using nFLH product of MODIS-A. This quasi-permanent bloom could not be precisely observed using chlorophyll concentration in the turbid coastal waters due to the presence of other optically active constituents; hence, chlorophyll fluoresce is used to study the bloom phenomenon from nFLH product of MODIS. The analysis has been carried out by analysing the spectral variability using both in situ and satellite Rrs spectra over the bloom and non-bloom waters. Comparative study between in situ chlorophyll with satellite-derived FLH showed a good correlation with an R2 of 0.43. The bloom phenomenon observed/assessed from the MODIS nFLH data showed > 0.25 W m−2 sr−1 μm in the bloom-dominated pixels. This proves that the satellite-derived nFLH can also be used as an indicator in detecting the phytoplankton blooms and also as one of the important parameters for the ocean colour applications in case-II waters.