Spatiotemporal variability/stability analysis of NO2, CO, and land surface temperature (LST) during COVID-19 lockdown in Amman city, Jordan

The massive lockdown of human socioeconomic activities and vehicle movements due to the COVID-19 pandemic in 2020 has resulted in an unprecedented reduction in pollutant gases such as Nitrogen Dioxide (NO2) and Carbon Monoxide (CO) as well as Land Surface Temperature (LST) in Amman as well as all countries around the globe. In this study, the spatial and temporal variability/stability of NO2, CO, and LST throughout the lockdown period over Amman city have been analyzed. The NO2 and CO column density values were acquired from Sentinel-5p while the LST data were obtained from MODIS satellite during the lockdown period from 20 March to 24 April in 2019, 2020, and 2021. The statistical analysis showed an overall reduction in NO2 in 2020 by around 27% and 48% compared to 2019 and 2021, respectively. However, an increase of 7% in 2021 compared to 2019 was observed because almost all anthropogenic activities were allowed during the daytime. The temporal persistence showed almost constant NO2 values in 2020 over the study area throughout the lockdown period. In addition, a slight decrease in CO (around 1%) was recorded in 2020 and 2021 compared to the same period in 2019. Restrictions on human activities resulted in an evident drop in LST in 2020 by around 13% and 18% less than the 5-year average and 2021 respectively. The study concludes that due to the restrictions imposed on industrial activities and automobile movements in Amman city, an unprecedented reduction in NO2, CO, and LST was recorded.