When the number of confirmed coronavirus disease cases rose in Iraq in the middle of February 2021, the Iraqi government performed a closure approach to constrain mobility and factory operations and enforce social distancing. In this research, the concentrations of air components (PM2.5, PM10, nitrogen dioxide (NO2) and ozone (O3)), which represent herein the degree of air quality index, were recorded, drawn and evaluated over central (Baghdad, the capital), northern (Kirkuk Province) and southern (Basra Province) Iraq before and during the closure. The experimental duration of this research was 6 months (from 1 January 2021 to 30 June 2021), which included four periods: pre-closure, first closure (total and partial), second closure (total and partial) and third closure (partial). Moreover, the impact of total closure and partial closure on the quality of the atmospheric layer over Iraq was evaluated and assessed by using Sentinel-5P satellite/Tropospheric Monitoring Instrument and Giovanni–Earthdata images. The results revealed that air pollutant concentrations dropped during the closure periods except at the end of the third closure period due to the lack of people’s commitment by breaking the closure strategy based on economic reasons. It was observed that the lockdown is one of the best solutions to defeat the coronavirus pandemic and that it significantly improved the air quality index, although it has several disadvantageous effects on the economic front of the country. Eventually, since people stay at their residences, the concentration of air pollutants becomes low and the air quality index becomes better.
