Fig. 2: Performance of the Random Forest (RF) model for predicting γNO2 and the relative importance of individual factors.

a The linear relationship between the observed γNO2 and the predicted γNO2; b The time series of the observed and the predicted γNO2; c The relative importance of each factor for the γNO2; d The SHAP (Shapley additive explanations) value of each feature variable, T: Temperature; ALWC: Aerosol Liquid Water Content.