Spatio-temporal analysis of nitrogen dioxide (NO(2)) from Sentinel-5P imageries using Google Earth Engine changes during the COVID-19 social restriction policy in jakarta

The number of cases due to COVID-19 is increasing, especially in Jakarta, requiring the government to establish a policy of social restrictions. The policy impacting the mobility of people using motor vehicles becomes limited, affecting air quality such as Nitrogen Dioxide (NO(2)). NO(2) concentrations can be determined using the Sentinel-5P satellite using Google Earth Engine. This study analyzed NO(2) changes and people's mobility in residential and workplace categories through google mobility data in Jakarta spatially and temporally for January 2020 to December 2021. The Pearson's correlation (R) between NO(2) from Sentinel-5P imageries and air quality monitoring stations was 0.426–0.736, indicating a moderate to strong correlation with a p-value <0.05. The decrease in NO(2) occurred at the beginning of the Large-Scale Social Restriction (PSBB) from April 2020 to May 2020 and the Implementation of Restrictions on Social Activities (PPKM) policy from July 2021 to August 2021; it was −11.381 ​μmol/m(2) and -23.195 ​μmol/m(2), with very low and low mobility in the residential and workplace categories. The area that experienced a change in NO(2) increase of 1 ​μmol/m(2), the highest occurred from May 2021 to June 2021 ​at 641.571 ​km(2). Meanwhile, from November 2020 to December 2020, no area experienced an increase of 1 ​μmol/m(2). We discovered that there were a number of anomalies when people's mobility in the residential and workplace category was very high, NO(2) actually decreased. This anomaly shows that the decrease in NO(2) is influenced by decreased mobility and other factors such as precipitation.