Rouf, MA; Antu, AH; Noor, MI (2020). Seasonal and annual variability in chlorophyll-a in the shelf region of the Northern Bay of Bengal using MODIS-Aqua data. OCEANOLOGICAL AND HYDROBIOLOGICAL STUDIES, 49(4), 398-407.

Chlorophyll-a (Chl-a) concentration is an important issue in ocean ecosystem management and research. This study investigates seasonal and annual variability in Chl-a and its relationship with sea surface temperature (SST) and river discharge in the shelf region of the Northern Bay of Bengal (BoB), as well as validates satellite data against insitu data. Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua satellite data on Chl-a concentration and SST from 2002-2018 were used in this study. River discharge data were obtained from the Bangladesh Water Development Board (BWDB). The annual Chl-a concentration ranged from 2.08 to 2.94 mg m(-3), with an average of 2.43 +/- 0.24 mg m(-3). The Chl-a concentration was found higher (2.21 +/- 0.56 mg m(-3)) during the northeast monsoon (October-February) and lower (1.81 +/- 1.14 mg m(-3)) during the pre-monsoon season (March-May). The study revealed a declining trend in Chl-a concentration from 2002 to 2018, and the rate of change was -0.0183 mg m(-3) year(-1). Chl-a concentration showed a weak inverse relationship with SST, both annually and seasonally, especially in the pre-monsoon season. River discharge masked the effect of SST on Chl-a variability during the southwest and northeast monsoon. A reasonable correlation (r = 0.78) was found between the MODIS-Aqua data and insitu Chl-a observations.