Fig. 4
From: Transforming CCTV cameras into NO2 sensors at city scale for adaptive policymaking
NO2 clock. It shows the hourly average levels of NO2 and the factors influencing these levels, based on a spatial regression model for each hour. It features three concentric circles: the innermost represents the average \(\hbox {NO}_2\) concentration per hour, the middle circle shows factors negatively correlated with NO2, and the outermost highlights positively correlated factors. Each factor’s influence is quantified by a \(\beta\) value, indicating its effect size relative to the hourly covariates, factors, and overall impact on NO2. All \(\beta\) values are standardised across all hours. For simplicity and clarity, the figure displays only four variables, although the full model considers a more extensive range of variables detailed in Table S1.
