Variations of Aerosol Radiative Forcing During Covid-19 Imposed Lockdown Over Ahmedabad City

ABSTRACT

In the present study Moderate Resolution Imaging Spectroradiometer (MODIS) onboard Aqua and Terra satellite derived Aerosol Optical Depth (AOD) and the Ozone Monitoring Instrument (OMI) onboard Aura satellite derived Single Scattering Albedo (SSA) data sets were used to demonstrate the regional variation in aerosol radiative forcing during covid-19 imposed lockdown over the urban climate of Ahmedabad city. An analysis of short-wave (0.25um to 4.0 um) Instantaneous Direct Aerosol Radiative forcing (IDARF) is done using these satellite data as inputs to the Radiative Transfer model - SBDART. Result shows reduction in IDARF by the month of April-2020 and highest reduction in the month of May. Value of IDARF for May is around 22.785 Wm-2, which is 40.21% less than the mean value of IDARF from pre lockdown to post lockdown. Which indicates Negative Radiative Forcing (Net Cooling Effect). Magnitude of IDARF during lockdown and post lockdown are found to be 34.49 Wm-2 and 71.62 Wm-2 which is 87.94% higher than the mean value of IDARF from pre lockdown to post lockdown. Which suggest Positive Radiative Forcing (Net Warming Effect). © 2021 IEEE.