Spatiotemporal Changes in aerosol loadings across Bangladesh from 2010-2021

Abstract

Climate simulations are uncertain due to aerosols' significant contribution to the atmospheric process. In current climate diagnostics, it is vital to assess aerosols properly. The present study investigated spatiotemporal changes in aerosol loadings across Bangladesh based on Terra-MODIS (Moderate Resolution Imaging Spectroradiometer) aerosol products (at 550 nm) during the time period 2010–2021. Results of this study showed high aerosol loadings (Aerosol Optical Depth, AOD >0.6) throughout the entire country excluding some small areas of the Chattogram and Sylhet divisions. Post-monsoon aerosol loadings were the lowest and pre-monsoon and winter aerosol loadings were the highest. The highest aerosol loadings (0.87) demonstrated in June whereas the lowest (0.46) in October. The regional AOD patterns in eight distinct divisions of Bangladesh were studied, all the divisions were showing increasing trends of AOD. The highest AOD levels were found in Rajshahi and Khulna but the highest increasing rate of AOD was reported in Rangpur. At the Dhaka University site (Bhola site), the correlation (r) between satellite and ground-based measurements was 0.82 (0.80) for Dark Target (DT) and 0.87 (0.76) for Deep Blue (DB), suggesting further applications can be made to these datasets.