Optical classification of waters in the eastern arabian sea

The optical properties in a non-spectral mode covering Photosynthetically Active Radiation (PAR) was estimated in the Arabian Sea in the west coast of India. The attenuation coefficients, light transmittance and K/c ratio were found useful for classification of water bodies in the coastal and offshore region. High values of turbidity and Chlorophyll-a in coastal waters associated with comparatively higher values of diffusive attenuation coefficients for upwelling and downwelling irradiances. On the basis of attenuation coefficients and K/c ratio derived from upwelling and downwelling irradiances, the water bodies were classified as defincd by Jerlov (1976). The coastal waters are classified under Jerlov water types of 3 to 9, whereas those of offshore are falling under the categories Ia, Ib and II.