Investigations of relationship between surface ozone and temperature in the Beijing-tianjin-hebei region
To investigate the influence of meteorological conditions on long-term ozone(O3)trends,two climate penalty factors were analyzed with observed pollutant and meteorological data from multiple stations in the Beijing-tianjin-hebei region.Results demonstrated that the sensitivity of O3 to temperature enhanced after 2016.Compared the two periods before and after 2016(2010~2015,P2;2016~2020,P3),we found that high-temperature weather contributed to this phenomenon.The frequency in high-temperature days in the P3 period was 0.6%~5.1%higher than that in the P2 period,which was related to the enhanced influence of foehn on the plain areas during the P3period.The occurrence frequency of foehn in the P3stage was 2.7 times higher than that in the P2 stage,and the occurrence frequency of high-temperature weather under the foehn condition was 1.0~1.9times higher than that under the non-foehn condition.The enhanced sensitivity of O3 to temperature indicated that once the meteorological conditions are favorable for O3 pollution,the O3 concentration will peak in a short time,and the high concentration of O3 can be maintained for a longer time.In contrast to Beijing,pollution in other areas of the Beijing-tianjin-hebei region was severer than Beijing,and joint prevention need to be continuously strengthened.