Publications

Nair, AS; Soni, K; Singh, P; Meena, K; Sharma, R (2023). Aerosol Variability at Coastal Bhola Island (Bangladesh), an IGP Outflow Region. JOURNAL OF THE INDIAN SOCIETY OF REMOTE SENSING, 51(5), 1013-1035.

Abstract
The aerosol optical depth (AOD) and angstrom ngstrom parameters are recognised to be pivotal factors in understanding the status of ambient aerosol concentrations over a certain place and depend not only on the local but also on large-scale atmospheric dynamics. Aerosol climatology was undertaken across coastal Bhola Island for 7 years (2014-2021), using data from the Aerosol Robotic Network (AERONET). This study provides a protracted scrutiny of daily, monthly, seasonal and interannual variations of the AOD and angstrom ngstrom parameters for Bhola. The observed columnar AOD was analysed to offer a hitherto unknown temporal picture of trends in aerosol pollution over Bhola. During the study period (2014-2021), the AOD value increased from 2015-2019 to 2020-2021. The AOD value was >= 0.70 except for 2014-2015 and 2019-2020. The seasonal mean AOD over Bhola was > 0.3, highest in January and February (winter) and lowest in July (monsoon). Coarse-mode fractions during winter and fine-mode fractions during rest, corroborate the seasonal pattern of AODs and a (angstrom ngstrom wavelength exponent). The average a was found to be[ 1 during the inter-annual comparison, implying the ubiety and predominance of fine-mode aerosol. The average alpha' (second order angstrom ngstrom exponent) value was positive, with an overall cumulative count of 90% of the data having positive alpha' validating the pre-eminence of fine-mode aerosols. The beta (angstrom ngstrom turbidity coefficient) value proportionally varied with respect to AOD, whereas it was inversely proportional to the alpha at a broader wavelength. The average beta varied between 0.2 and 0.4. The aerosols detected over the Bhola are of metropolitan/industrial, maritime, biomass combustion and dust origins, with proportionate inputs varying in various seasons. The current study data will be used for future investigations of Bhola's aerosols, pollution load, climate and atmospheric environment. Thus, this study is important as it facilitates the baseline data for policymakers and model simulation for pollution load and climate change analysis.

DOI:
10.1007/s12524-023-01681-5

ISSN:
0974-3006