01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-06-0198 |
| Title of Abstract | Contrasting Productivity Regimes of the Arabian Sea and Bay of Bengal: Perspective from Depth-resolved CbPM Modeling |
| Authors | Rupam Kalita*, Dr. Aneesh A. Lotliker |
| Organisation | Indian National Centre for Ocean Information Services (INCOIS) |
| Address | INCOIS pragathi nagar, Telangana, India Pincode: 500090 E-mail: rupamk0@gmail.com |
| Country | India |
| Presentation | Oral |
| Abstract | Understanding the contrasting productivity regimes of the Arabian Sea (AS) and Bay of Bengal (BoB) is critical for improving biogeochemical modeling and carbon cycling estimates in the Northern Indian Ocean. In this study, the Carbon-based Productivity Model (CbPM) was implemented locally at 4 km spatial resolution, using satellite-derived chlorophyll and backscatter data along with high-resolution physical and biogeochemical inputs including HYCOM mixed layer depth (MLD), ROMS-Fennel nitracline depth, and MODIS ocean color products. Monthly Net Primary Productivity (NPP) from June 2023 to May 2024 was estimated by vertically integrating up to the euphotic depth (Zeu), providing a depth-resolved characterization of primary productivity drivers across seasons and regions. The results reveal distinct basin-scale differences in the mechanisms regulating NPP. The AS exhibited strong seasonal variability, with elevated productivity during the pre monsoon and post-monsoon months driven by coastal upwelling and convective mixing nutrient entrainment. In contrast, the BoB showed comparatively lower seasonal variations, but maintained moderate and consistent productivity, particularly during stratified periods. This sustained productivity in BoB is linked to a better vertical alignment of the chlorophyll layer, higher euphotic depth and nitracline depth than MLD, although stratification restricts deep mixing but retains phytoplankton in light-favorable conditions. These findings demonstrate that surface chlorophyll alone is insufficient to capture productivity variability, and that vertical coupling between light, nutrients, and biomass plays a dominant role. The depth-aware, high-resolution CbPM framework employed here provides a good representation of primary production and offers insight into regional responses of ocean productivity to seasonal forcing in the northern Indian Ocean. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Primary Productivity, northern indian ocean, biogeochemistry, CbPM |
| For Awards | yes |
| Date Of Birth | 25-03-1995 |
| ECSN Registration Number | IIOE2-ECSN-0122 |