On watermass mixing ratios and regenerated silicon in the Bay of Bengal

Abstract

Regeneration of silicon on mixing in the Bay of Bengal have been computed from six water masses [Bay of Bengal low saline water (BBLS), Bay of Bengal subsurface water (BBSS), northern southeast high salinity water (NSEHS), north Indian intermediate water (NIIW), Indonesian throughflow water (ITW) and Antarctic bottom water (AABW)]. The distribution of watermass fractions showed that BBLS with a maximum of 80-90% in the 40-60 m depth range and BBSS with 50% in the 150-300 m depth range are prominant. In the intermediate layers, NIIW shows a maximum percentage of 40% in 250-700 m depth region while ITW shows a maximum of 60% in 800-1000 m depth region. The deeper layers (below 3000 m) are predominantly occupied by AABW with a maximum of 70%. Silicon regeneration consequent upon watermass mixing has been worked out based on the characteristics of silicon for individual watermass.