Variation of Aerosol Optical Depth and Radiative Forcing Over Indo-Gangetic Plain using AERONET

Abstract

Aerosols play a crucial role in the atmosphere and significantly modify the earth's radiation budget. Due to their scattering and absorbing nature, aerosols have a significant impact on the global climate. In the present work, the monthly variation of aerosol properties has been studied over three different sites of Indo-Gangetic Plain (IGP): Kanpur, Jaipur, and Gandhi College respectively using ground-based Aerosol Robotic Network (AERONET) data. The spectral variations of Aerosol Optical Depth (AOD) with different seasons have been analyzed from June 2020 to May 2021. The high value of AOD at shorter wavelength and low value of AOD at longer wavelength was found which suggest dominancy of fine particles in the winter season and dominancy of coarse particles in the summer season. The monthly variation of Aerosol Radiative Forcing (ARF) along with trends over Kanpur, Jaipur, and Gandhi College has been analyzed. Total atmospheric radiative forcing <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(\text{ARF}_{\text{ATM}})$</tex> over all the locations was found to be positive suggesting warming in the atmosphere. The trend of ARF over Jaipur was found to be significantly decreasing while the trend of ARF over Kanpur and Gandhi College is insignificant. The correlation between AOD and <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\text{ARF}_{\text{ATM}}$</tex> was calculated. It is found that Aerosol Radiative Forcing is directly proportion to the Aerosol Optical Depth having a correlation coefficient of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathrm{R}^{2} &gt; 60$</tex> % which suggests that aerosols can modify the Earth's radiation budget significantly.