THE RELATIONSHIP BETWEEN BEAM ATTENUATION AND CHLOROPHYLL CONCENTRATION AND REFLECTANCE IN ANTARCTIC WATERS

Optical and biological data collected during the two-month R.R.S Disco very expedition in Antarctic waters in the Austral spring were used to examine the relationships between c(660 nm), chlorophyll a and the re flectance ratios R(443)/R(550), R(490)/R(550) and R(443 nm). Values of (c-c(w))(660 nm) varied from 0.20 to 1.2 m(-1), being generally posit ively correlated with the chlorophyll concentration. The computed valu es of the pigment specific beam attenuation coefficient c were greate r than those typical in Case I waters, exceeding 0.9 m(2) mg(-)1, redu cing the accuracy of the chlorophyll remote sensing algorithms designe d for Case I waters. The covariance of phytoplankton and related pigme nts with beam attenuation was examined by the regression equation c-c( w)= A + B(Chl a + phaeo), and the residuals were used to identify the non-chlorophyll dependent data in the region. When the non-chlorophyll dependent data were removed, the accuracy of the chlorophyll remote s ensing model was significantly improved.