A dust storm during June 2013 and its impacts on Aerosol optical depth over Lahore

Abstract The impact of dust aerosols on Aerosol Optical Depth (AOD) at 500nm and Angstrom exponent (AE) at the spectral range 440–870 nm over Lahore from 1st to 5th June 2013 has been analyzed by using groundbased Aerosol Robotic Network (AERONET). The AOD values range from 0.64 to 1.04 and AE values ranges from to 0.56 to 0.87. Diurnal AOD variations during a dust outbreak on 3rd June are in the range of 0.74-1.51. A significant impact of dust aerosols on the AOD and AE was found on a dusty day as compared to that on a non-dusty day. The AOD reached a high value of 1.04 with a corresponding decrease in AE to 0.56 during the dust storm. A reverse relation between AOD and AE values has been reported. Analysis of the backward trajectory with the help of Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model were used to know the pathways of the dust aerosols due to dust activities reaching the study site were originated from Nepal and Sindh desert in Pakistan. Keywords: Dust, Aerosol Optical Depth, Angstrom exponent, Lahore