| Abstract Submission No. | ABS-1.2-0009 |
| Title of Abstract | Monsoonal and Depth-Resolved Variability of Particulate Organic Carbon in the Bay of Bengal. |
| Authors | Pavithra Balamurugan*, Alexkirubakaran Augustinraj, Saravanakumar Ayyapan, Kande Vamsi Krishna |
| Organisation | Annamalai University |
| Address | Centre of Advanced Study in Marine Biology, Annamalai University PARANGIPETTAI, Tamil Nadu, India Pincode: 608502 E-mail: pavithrabalamurugan777@gmail.com |
| Country | India |
| Presentation | Poster |
| Abstract | Particulate Organic Carbon (POC) is a vital component of the global carbon cycle, linking surface ocean productivity to deep-ocean sequestration through the biological carbon pump. However, its variability in the Bay of Bengal remains poorly constrained due to strong monsoonal forcing and freshwater influence. In this study, we investigate monsoonal (pre- and post-monsoon) and depth-resolved distributions of POC along the southwest Bay of Bengal, based on in-situ observations collected during February 2024 (post-monsoon) and July-August 2024 (pre-monsoon) from four coastal transects (Nagapattinam, Pazhayar, Mahabalipuram, and Chennai). POC concentrations were consistently higher during the pre-monsoon (128-404 mg C m⁻³) than the post-monsoon (62-182 mg C m⁻³), reflecting enhanced phytoplankton productivity under stratified conditions. Depth profiles revealed maxima at the surface and Deep Chlorophyll Maximum (DCM), with sharp declines toward 100 m driven by remineralization processes. Regional differences were evident, with Pazhayar and Chennai showing elevated POC influenced by freshwater and nutrient inputs, while Mahabalipuram exhibited lower, more oligotrophic conditions. These results demonstrate that POC dynamics in the southwest Bay of Bengal are primarily regulated by monsoon-driven stratification, freshwater inflow, and biological activity, with implications for coastal carbon export, sequestration, and regional carbon budgets. This study provides new insights into the role of monsoon-influenced marginal seas in regulating the marine carbon cycle. |
| Keywords | Keywords: Particulate Organic Carbon, Chlorophyll, Deep Chlorophyll Maximum, Phytoplankton |