Phytoplankton pigment/temperature relationship in the Arabian Sea

A single date Coastal Zone Colour Scanner (CZCS) (onboard Nimbus 7 satellit e) image of north west coast of India covering the area off Bombay and furt her south for March showed distinct patterns of pigment distribution. The s ingle channel thermal data when density sliced shows resemblance with the p igment distribution pattern particularly in the offshore waters. The mean m onthly pigment map derived from CZCS data showed seasonal change both quali tative as well as quantitative. The climatological oceanographic temperatur e data shows variation with season and different patterns at different dept hs are observed. However, when compared with the pigment distribution patte rn the temperature contour at 50 m depth shows a close match with the pigme nt concentration contours of 0.2 mg. m(-3) and 0.6 mg. m(-3) particularly d uring March, September and October. The contours of 2 mg, m(-3)) and 0.6 mg . m(-3) correlate with the temperature contours of 26 degrees C and 24 degr ees C respectively. However, for other months no specific correlation is se en. It is observed that during these months which represents transition pha se between northeast (March) and southwest (September, October) monsoon the MLD tends to be shallower. In the Arabian Sea the pigment distribution ref lects the introduction of nutrients into the photic zone. The maximum annua l pigment biomass in the Arabian Sea occurs when the mixed layer is relativ ely shallow. Therefore, at the time of sufficiently shallow MLD and less tu rbulent conditions the pigment and temperature pattern show covariation. Fo r any modeling activity such understanding is crucial factor when inter-rel ationship of physical/biological oceanographic parameters is involved. This provides a useful input for modeling the coupling between physical and bio logical oceanographic parameters.