深圳市秋季大气臭氧立体分布特征

利用大气O₃探测激光雷达在深圳市东部生态区和西部城区同步开展垂直观测，探究了2018年深圳市O₃立体分布在秋季光化学污染活跃期至冬季非活跃期的演变过程.结果表明：光化学反应活跃的10月，东部地面O₃浓度相对于西部地面高出约128%；地面向上至450m，O₃浓度在东部生态区发生快速降低，而在西部城区由于存在“滴定效应”，O₃浓度随高度升高而升高；450m~2km，东、西部O₃浓度均随高度升高而降低，西部城区O₃浓度水平超过东部生态区约30%；2km以上高空，东、西部O₃浓度趋同（70μg/m³），并保持稳定，为具深圳市秋季O₃污染过程提供了较高的大气背景浓度.高污染期间，深圳市大气边界层内O₃浓度变化较为一致，西部高空的O₃区域传输作用更加显著.秋季至冬季光化学反应逐渐减弱，深圳市O₃浓度的水平和垂直空间差异逐渐减小，冬季的深圳市O₃污染基本受大气背景控制.

Vertical distribution characteristics of ozone pollution in Shenzhen in autumn

Simultaneous O₃ observation was carried out in both the eastern natural ecological zone and the western urban living area in Shenzhen from the autumn with high photochemical activity to the winter with low photochemical activity in 2018, and then the evolution process of O₃ was explored and discussed. The results showed that during October, the O₃ concentration observed in the eastern site was 128% higher than that in the western site near the ground. From the ground to an elevation of 450m, the O₃ concentration in the east decreased. Conversely, due to the titration effect occurring in the west, the concentration of O₃ increased in proportion to the elevation up to 450m. From 450m to 2km, the O₃ concentration decreased at both sites, with the O₃concentration in the western area being about 30% higher than that in the eastern area. The O₃ concentration above 2km was generally stable and can be regarded as the background concentration (~70µg/m³), providing a high regional background concentration for the autumn O₃ pollution in Shenzhen. Analysis of high pollution process showed that the O₃ pollution variation was consistent within the atmospheric boundary layer in Shenzhen, indicating that O₃ pollution was significantly affected by regional transport. The transport of O₃ at the high altitudes in the western area was more prominent. From autumn to winter, the O₃ concentration decreased continuously due to the weakened photochemical reactions, and the horizontal and vertical variation of O₃ concentration also decreased in Shenzhen. The O₃ pollution level was essentially controlled by the regional background inwinter in Shenzhen.