Development of bio-physical model for the estimation of zooplankton biomass production in the Arabian Sea using remotely sensed oceanographic variables

Abstract

<span style="font-size:9.0pt;font-family: " times="" new="" roman";mso-fareast-font-family:"times="" roman";mso-bidi-font-family:="" mangal;mso-ansi-language:en-gb;mso-fareast-language:en-us;mso-bidi-language:="" hi"="" lang="EN-GB">A bio-physical model was developed to estimate zooplankton production in the Arabian Sea using satellite derived chlorophyll concentration (CC) and sea surface temperature (SST). For this, US Joint Global Ocean Flux Study (US JGOFS) 1995 cruises in-situ data has been used. A 3D plot was generated using in-situ measured chlorophyll, temperature and zooplankton bio-mass. Scatter plot indicated linear and exponential relationship between CC - zooplankton biomass, temperature and zooplankton, respectively. A typical range of 24º-26º C water temperature was found preferable for zooplankton production. Based on this study a multiple regression analysis was carried out to derive coefficients for the development of algorithm. Correlation co-efficient (r²) of multiple regression analysis was 0.78. An empirical algorithm was developed using these co-efficient. This algorithm was applied to Oceansat-1 derived chlorophyll concentration and NOAA-AVHRR derived SST to generate zooplankton images showing zooplankton biomass distribution and concentration. Model was validated through synchronous in-situ observations. Zooplankton biomass was measured on board Sagar Kanya and Sagar Sampda in the Arabian Sea. Regression analysis indicated co-relation co-efficient (r²) = 0.74.</span>