01-05 December 2025
INCOIS, Hyderabad, India.
| Abstract Submission No. | ABS-05-0314 |
| Title of Abstract | Extreme Weather-Induced Environmental Changes and Their Impact on Marine Biogeochemistry in the Northern Bay of Bengal |
| Authors | Md. Ibrahim *, Md. Leion Hassan , Md. Enamul Hoque , Md. Rakibul Islam Shanto |
| Organisation | Department of Oceanography, University of Chittagong |
| Address | University of Chittagong Hathazari, Chattogram, Bangladesh Pincode: 4331 E-mail: ibrahim.ocean.cu@gmail.com |
| Country | Bangladesh |
| Presentation | Poster |
| Abstract | The Northern Bay of Bengal (NBoB), a cyclone-prone region of the global ocean, experiences extreme weather conditions that radically alter biogeochemical processes through intense vertical mixing, nutrient redistribution, and phytoplankton biomass changes. This study discusses the spatio-temporal distribution of nitrate (NO⿿), phosphate (PO⿿), silicate (Si), dissolved iron (dFe), and chlorophyll-a (Chl-a) due to three recent cyclones⿿post-monsoon Sitrang (2022), post-monsoon Hamoon (2023), and pre-monsoon Mocha (2023)⿿from daily datasets of the Copernicus Marine Service in five hydrographic regions. Statistical comparison of the pre-, during-, and post-cyclone seasons reveals that post-monsoon events triggered abrupt Chl-a peaks of 3⿿4 days' duration before declining with winter transitions, while pre-monsoon conditions created gradual build-ups lasting into the monsoon. PO⿿ and Si traced similar seasonal trajectories, while NO⿿ and dFe built up progressively into the monsoon but dropped dramatically at landfall. Comparative analysis identifies NO⿿ as the dominant regulator of cyclone-induced phytoplankton blooms, with increasing Si limitation during post-monsoon cyclones and severe iron limitation before the monsoon; PO⿿ was never limiting. Biogeochemical gradients were most pronounced nearshore, reflecting the complex interaction between regional hydrography and cyclone forcing. These findings demonstrate that cyclone-induced nutrient dynamics in the NBoB are seasonally controlled, nutrient-specific, and spatially heterogeneous, emphasizing the need for sustained monitoring to predict ecological outcomes in a regime of accelerating extreme weather events. |
| Are you part of IIOE-2 endorsed project | no |
| Keywords | Tropical Cyclones, Northern Bay of Bengal, Ocean Primary Productivity, Seasonal variation, Phenology, Marine biogeochemistry. |
| For Awards | yes |
| Date Of Birth | 18-09-1999 |
| ECSN Registration Number | IIOE2-ECSN-0202 |