Wang Honglei, Tan Yue, Zhang Lianxia, Shen Lijuan, Zhao Tianliang, Dai Qihang, Guan Tianyi, Ke Yue, Li Xia
Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science &Technology, Nanjing, 210044, China.
State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing, 100081, China.
Atmos Pollut Res. 2021 Dec;12(12):101247. doi: 10.1016/j.apr.2021.101247. Epub 2021 Oct 27.
The diverse climate types and the complex anthropogenic source emissions in China lead to the great regional differences of air pollution mechanisms. The COVID-19 lockdown has given us a precious opportunity to understand the effect of weather conditions and anthropogenic sources on the distribution of air pollutants in different climate zones. In this study, to understand the impact of meteorological and socio-economic factors on air pollution during COVID-19 lockdown, we divided 358 Chinese cities into eight climate regions. Temporal, spatial and diurnal variations of six major air pollutants from January 1 to April 18, 2020 were analyzed. The differences in the characteristics of air pollutants in different climate zones were obvious. PM reduced by 59.0%-64.2% in cold regions (North-East China (NEC) and North-Western (NW)), while O surged by 99.0%-99.9% in warm regions (Central South (CS) and Southern Coast (SC)). Diurnal variations of atmospheric pollutants were also more prominent in cold regions. Moreover, PM, PM, CO and SO showed more prominent reductions (20.5%-64.2%) in heating regions (NEC, NW, NCP and MG) than no-heating regions (0.8%-48%). Climate has less influence on NO which dropped by 41.2%-57.1% countrywide during the lockdown. The influences of weather conditions on the atmospheric pollutants in different climate zones were different. The wind speed was not the primary reason for the differences in air pollutants in different climate zones. Temperature, precipitation, and air pollution emissions led to prominent regional differences in air pollutants throughout the eight climates. The effect of temperature on PM, SO, CO, and NO varied obviously with the latitude, at which condition temperature was negatively correlated to PM, SO, CO, and NO in the north but positively in the south. The temperature was positively correlated to ozone in different climate zones, and the correlation was the highest in NEC and the lowest in SC. The rainfall has a strong removal effect on atmospheric pollutants in the climate regions with more precipitation, but it increases the pollutant concentrations in the climate regions with less precipitation. In regions with more emission sources, air pollutants experienced more significant variations and returned to pre-lockdown levels earlier.
中国多样的气候类型和复杂的人为源排放导致空气污染机制存在巨大的区域差异。新冠疫情封锁给我们提供了一个宝贵机会，来了解天气条件和人为源对不同气候区空气污染物分布的影响。在本研究中，为了解新冠疫情封锁期间气象和社会经济因素对空气污染的影响，我们将中国358个城市划分为八个气候区域。分析了2020年1月1日至4月18日六种主要空气污染物的时间、空间和日变化。不同气候区空气污染物特征差异明显。寒冷地区（中国东北（NEC）和西北（NW））的PM下降了59.0%-64.2%，而温暖地区（中南（CS）和南部沿海（SC））的O激增了99.0%-99.9%。大气污染物的日变化在寒冷地区也更为突出。此外，供暖地区（NEC、NW、华北平原（NCP）和蒙古（MG））的PM、PM、CO和SO的降幅（20.5%-64.2%）比非供暖地区（0.8%-48%）更为显著。气候对NO的影响较小，封锁期间全国范围内NO下降了41.2%-57.1%。天气条件对不同气候区大气污染物的影响各不相同。风速不是不同气候区空气污染物差异的主要原因。温度、降水和空气污染排放导致八个气候区的空气污染物存在显著的区域差异。温度对PM、SO、CO和NO的影响随纬度变化明显，在这种情况下，温度在北方与PM、SO、CO和NO呈负相关，在南方呈正相关。温度在不同气候区与臭氧呈正相关，在NEC地区相关性最高，在SC地区最低。降雨对降水较多的气候区的大气污染物有很强的清除作用，但会增加降水较少的气候区的污染物浓度。在排放源较多的地区，空气污染物变化更为显著，且更早恢复到封锁前水平。
