Investigation of the aerosol's optical properties over the dust prevalent semi-arid region at Jaipur, northwestern India

Jaipur is a key site to study Aerosol Optical Depth (AOD) due to unpredictable variation of atmospheric Aerosols particles in the recent years. Aerosols Optical Depth (AOD) and Angstrom Exponent (AE) were investigated over the semi-arid region, Jaipur (26.9124° N, 75.7873° E) Northwestern India during the April-2009 to December-2017 utilizing AERONET CIMEL sun-photometer level-2 data for aerosols spatial and temporal characteristics. The Aerosols Optical Depth AOD500 nm, AOD440 nm, and AOD340 nm were observed maximum in July-2011 and minimum observed in March-2013. The monthly mean Angstrom Exponent (AE) was maximum (1.53 ± 0.43) for 500-870 nm, (1.49 ± 0.4) for 440-870 nm, and (1.19 ± 0.32) for 340-440 nm in September 2011, while the lowest value recorded (0.26 ± 0.12) for 340-440 nm, (0.16 ± 0.08) for 440-870 nm and (0.15 ± 0.07) for 500-870 nm during June 2014. The backward trajectories analysis was performed using the Hybrid Single-Particle Lagrangian Integrated Trajectories (HYSPLIT) model to determine the sources of large aerosol loadings over the Jaipur region, and air mass simulations from the back trajectory, suggest that the Thar desert northwestern part of India is the source of highest aerosols dust particle over the study area during the pre-monsoon season.