Ozone Formation Sensitivity at Various Altitudes: Seeking the Optimal Method for Sensitivity Threshold Determination

Several methods exist for determining ozone formation sensitivity using observational data, each potentially yielding different sensitivity classifications. This study examined the seasonal characteristics of MAX-DOAS data collected from both urban and rural sites in the Beijing–Tianjin–Hebei region. A multiple linear regression model was employed to isolate secondary HCHO data. The thresholds derived from four distinct methods were assessed, and the performance of these methods was evaluated across various elevations at both sites. Based on the findings, recommendations and the applicable ranges for each method are provided.