జర్నల్ ఆఫ్ ఎర్త్ సైన్స్ & క్లైమాటిక్ చేంజ్

నైరూప్య

Explaining Climate Variability Vis-A-Vis Spatio-Temporal Interactions in Bangladeshi Exclusive Economic Zone (BEEZ)

Nagabhatla N, Sahu SK, Altaf Arain M, Mahfuzul Haque ABM, Mitra A

We present an application of time series remote sensing data and climatological information for improved understanding of complexity in the Bangladeshi Exclusive Economic Zone (BEEZ). Three seasonal slots from the annual climate calendar of the temporal slice 1998 to 2009 are selected: December-February [DJF], March-May [MAM] and September-November [SON]) to assess the relationship between marine fish productivity and climate induced variations in a pelagic system. The interdisciplinary approach, explained in two segments, integrates data on climatic variables, oceanography and fish landings. The first segment deals with explanation of spatio-temporal distribution of chlorophyll (Chll-a), derived using Sea-WiFS sensor. This is followed by correlation of Chll-a gradient with marine fish productivity, using a proxy indicator –annual fish landings. The second segment examines the relationship between the Chll-agradient and representative biophysical indicators of the marine environment viz., Sea Surface Temperature [SST] and Sea Surface Height (SSH). The analysis from 1998-2009 indicates decline in Chll-a concentration during SON (0.055 mg/m3), DJF (0.012 mg/m3) and MAM (0.033 mg/m3). Fluctuations in Chll-a is explained in terms of increase in SST’s during DJF and SON and correlation between SST and SSH established in order to compliment the explanation for variability in Chll-a concentration.