2020年12月底广东大气污染过程与攻坚成效分析

Analysis on the Process of Air Pollution and Effect of Tackling in Guangdong at the End of December 2020

近年来,广东省每年12月PM_(2.5)超标城次数大幅度下降,NO_(2)超标情况反复,臭氧超标城次数波动上升,凸显出在全球变暖背景下,广东冬季污染态势已从以PM_(2.5)为主向以O_(3)为主转变。2020年12月底广东省的大面积大气复合污染主要是由近地面风速较弱、太阳辐射相对较强等不利于扩散与有利臭氧生成的气象条件,以及年底生产活动活跃,大气污染物排放量相对较大等原因造成。主要污染城市位于广东省中部,但受污染区域输送的影响,云浮等周边排放相对少的城市也出现了臭氧超标情况。自12月26日启动百小时应急行动以来,27-29日实际超标13城次,比预测污染城次数减少了约66%,广东形成了有效的大气复合污染应对模式,提升了AQI达标率,保证了全年大气质量约束性指标的完成。

In recent years,the number of cities where PM_(2.5)exceeds the standard in December dropped significantly,but NO_(2)exceeded the standard repeatedly,and the number of cities with ozone exceeding the standard has fluctuated more.It highlight⁃ed that Guangdong’s winter pollution situation has changed from PM_(2.5)problem to ozone pollution under the background of global warming.At the end of December 2020,the large-scale compound air pollution in Guangdong was mainly due to the meteorological conditions that were not conducive to diffusion,but conducive to ozone generation,such as weak wind speed near the ground and relatively strong solar radiation.In addition,active production activities at the end of the year and relative⁃ly large emissions of air pollutants were also key reasons for that.The main polluted area was located in the central part of Guangdong.However,due to the transportation of pollution,ozone concentration in Yunfu and other cities with relatively low emissions also exceeded the standard.Since the 100 hour emergency action was launched on December 26,13 cities actually exceeded the standard from 27 to 29,about 66%less than the predicted number of polluted cities,forming a response mode of air combined pollution,which could effectively improve the AQI compliance rate,and ensure the completion of the annual air quality binding indicators.