京津冀区域臭氧时空分布特征及其背景浓度估算

为研究京津冀区域臭氧时空分布特征，并估算区域传输贡献，对2017~2019年京津冀区域68个国控站点资料进行主成分分析，并采用TCEQ法估算京津冀区域及细分的次区域内O₃背景浓度.结果表明，京津冀区域O₃浓度整体上呈现南高北低态势，地理位置的差异及其距离对于各城市臭氧浓度的均匀性分布影响较大.经最大方差法旋转后，主成分分析结果可将京津冀区域划分为河北省中南部、京津冀北部以及渤海西岸地区等3个稳定的次区域.对3个次区域分别采用TCEQ法估算O₃背景浓度，计算得到3个次区域本地生成O₃浓度依次为71，60，59μg/m³，区域背景浓度占O₃日最大8h浓度的比值依次为34.3%，39.4%，42.2%.京津冀区域O₃本地生成占主导，区域传输也不容忽视.

Temporal and spatial distribution characteristics and background concentration estimation of ozone in Beijing-Tianjin-Hebei region

In order to study the temporal and spatial distribution characteristics of ozone in Beijing-Tianjin-Hebei region and estimate the regional transport contribution, the principal component analysis was carried out on the data of 68 national control stations in Beijing-Tianjin-Hebei region from 2017 to 2019, and the TCEQ method was used to estimate the background concentration of ozone in Beijing-Tianjin-Hebei region and subdivided sub-regions. The results showed that the ozone concentration in Beijing-Tianjin-Hebei region was high in the south and low in the north as a whole, and the difference of geographical location and its distance had great influence on the uniform distribution of ozone concentration in different cities. After the rotation of the maximum variance method, the Beijing-Tianjin-Hebei region could be divided into three subregions:the central and southern part of Hebei Province, the north of Beijing-Tianjin-Hebei region and the west coast of the Bohai Sea. Using the TCEQ method to estimate the ozone background concentration in the three subregions could reduce the influence of geographical factors. The calculated results showed that the locally generated ozone concentrations in the three subregions are 71, 60 and 59μg/m³, respectively, and the ratio of the regional background concentration to the maximum 8-hour concentration in ozone days was 34.3%, 39.4% and 42.2%, respectively. The local generation of ozone in Beijing-Tianjin-Hebei region was dominant, and regional transmission could not be ignored.