Remote Sensing Analysis of Spatiotemporal Variability in Key Physicochemical Parameters and Primary Productivity in the Northern Bay of Bengal

The Bay of Bengal (BoB), a vital marine ecosystem, is influenced by complex interactions between physical, chemical, and biological processes. Monsoonal winds, riverine inputs, and oceanographic conditions shape the region's unique characteristics. This study leverages high-resolution remote sensing data from 2014 to 2023 to analyze the spatiotemporal variability of key physicochemical parameters and their impact on primary productivity. The study reveals distinct seasonal patterns in sea-surface temperature (SST), salinity, density, mixed-layer depth (MLD), dissolved oxygen (DO), and chlorophyll- a concentration and monthly variations of these parameters. The analysis indicates that the Northern part of BoB recorded its highest SST in May, with levels rising to 29°C. Primary productivity exhibits two peaks, one during the spring season, which is 405 to above 905 mg/m³/day and another during the autumn season (305 to 705 mg/m³/day), driven by increased nutrient availability and favorable light conditions. The lowest productivity was observed in the winter season, with the value 5 mg/m³/day, attributed to a lower temperature (25°C) and reduced light availability. The study highlights the influence of environmental factors on marine biological activity, with high temperature, low salinity, low dissolved oxygen, and shallow mixed-layer depth correlating with higher chlorophyll- a concentration. This research provides valuable insights into the BoB's ecosystem health and productivity, emphasizing the importance of remote sensing in monitoring and understanding this dynamic marine environment.