京津唐地区臭氧时空分布特征与气象因子的关联性研究

京津唐地区随着经济的快速发展和城市化的不断推进，臭氧污染呈现加重的趋势，深入了解臭氧浓度时空变化特征及其变化驱动机制是采取科学有效防控措施的前提和基础.本研究针对京津唐地区近地面臭氧浓度快速增加的2016年，利用卫星遥感反演数据、地面每小时监测数据及气象观测资料，分析探讨了近地面臭氧浓度时空分布及与温度、压强、蒸发量、风（风速和风向）等气象要素的耦合关联关系.结果表明：京津唐地区近地面臭氧浓度每日7：00左右最低，午后达到最高；夏季臭氧浓度最高，且略有分区差异（北京呈现单峰型，6月臭氧浓度最高，天津和唐山呈双峰型，峰值分别出现在6月和9月），冬季浓度最低，12月达到最低值.全区各季节浓度空间分布趋势较为一致，均呈现从西北向东南逐渐降低的趋势.影响京津唐地区近地面臭氧浓度的首要气象要素为温度，二者呈较大的正相关性，臭氧浓度与近地面压强存在一定的负相关性，而与蒸发量具有较小的正相关性，与风速、风向的相关性较为复杂，表现出明显的地区和风向差异性（在偏南风和强风条件下较易出现高浓度臭氧），全年臭氧浓度与风速相关系数极低，呈不相关.全区分区（建成区与非建成区）近地面臭氧浓度与温度、压强、蒸发量、风速等的关联相关特性，虽然北京、天津和唐山各略有差异但基本一致.在不同气象要素分级组合协同条件下，臭氧浓度与温度、风速的相关性明显显著于其与蒸发量、压强的相关性，且存在在高压、较低蒸发量的气象条件下，臭氧浓度与温度的相关性随风速的增强（或减弱）而降低（或增强），与风速的相关性随温度的升高（或降低）而减弱（或增强）的普遍现象；对于压强和蒸发量而言，臭氧浓度与二者的相关性普遍相对较低，且趋势特征不明显.

Analysis of temporal and spatial variations of ozone coupling with dynamics of meteorological factors in the Beijing-Tianjin-Tangshan region

In recent years, ozone pollution in the Beijing-Tianjin-Tangshan region has become serious owing to rapid economic development and urbanization, and it is a basic prerequisite of formulating effective control measures to deeply understand the spatiotemporal variation of near-surface ozone (O₃) concentration and its driving mechanism. In this study, satellite remotely sensed inversion data and hourly ground monitoring observations of near-surface ozone concentrations and meteorological data in 2016, when ozone pollution accelerated sharply in this study area, were used in exploring the spatiotemporal dynamic characteristics of near-surface ozone concentration, as well as their coupling relationship with meteorological factors, including temperature, pressure, evaporation, and wind (wind speed and direction). The results showed that the near-surface ozone concentrations in the Beijing, Tianjin, and Tangshan areas reached a maximum value at approximately 3:00 to 4:00 p.m. daily and a minimum value at approximately 7:00 a.m. in 2016. Their highest average values occurred in Summer (i.e., which appeared in Beijing area in June, but manifested as double peaks in the Tianjin and Tangshan areas in June and September, respectively) and their lowest average levels occurred in Winter. Regarding their spatial distribution in each season throughout this region, there existed an apparent consistency that showed a gradually decreasing tendency from northwest to southeast. Temperature was the primary meteorological factor resulting in the dynamics of near-surface ozone concentration in the Beijing-Tianjin-Tangshan region, and the two were well positively correlated. There was a negative correlation to a certain extent between the near-surface ozone concentration and pressure, but a small positive correlation between the near-surface ozone concentration and evaporation. The correlations with wind spend and direction in 2016 were extremely complex, which showed the distinct regional difference and wind direction feature (considering an example that, under southerly moderate, fresh, or strong breeze conditions, high ozone concentrations near the surface could easily appear), whereas the correlation coefficients between the near-surface ozone concentration and wind speed were extremely low all year round in the three subareas. So far, regarding the built-up and non-built-up areas were concerned, the correlation features between the near-surface ozone concentration and temperature, pressure, evaporation, and wind speed, were similar among Beijing, Tianjin, and Tangshan, although there were slight differences between them. Here, based on the conditions of hierarchical combination of meteorological elements, the correlations of the near-surface ozone concentration with temperature and wind speed were clearly more significant than that of the near-surface ozone concentration with evaporation and pressure. At the same time, under the combined conditions of high pressure and low evaporation, there existed common laws that the correlations of the near-surface ozone concentration with the temperature and wind speed increased (or decreased) with decreasing (or increasing) wind speed and temperature correspondingly. The correlations between the near-surface ozone concentration and pressure and evaporation were generally relatively low. In addition, their tendencies were not obvious.