[Spatio-Temporal Evolution Characteristics and Source Apportionment of O and NO in Shijiazhuang].

Ground-level O, NO, and meteorological (temperature, humidity, wind speed, precipitation, and sunshine duration) data from 18 counties in Shijiazhuang City from 2014 to 2017, and volatile organic compounds (VOCs) data for Summer 2017, were analyzed to explore the spatial patterns, evolution, influencing factors, and source apportionment of O and NO in Shijiazhuang City. Network analysis and inverse distance weighted (IDW) spatial autocorrelation and backward trajectories analyses were performed. The results indicate that O concentrations increased between 2014 and 2017, and monthly variations showed a unimodal trend.