Just after the Spring Festival holiday in Xi'an, compared with other cities in Guanzhong, the air quality in Xi'an is quite good. Among them, the concentration of PM2.5 on New Year's Eve in Xi'an and the contribution of fireworks to PM2.5 are lower than the same period last year, and far lower than other cities in Guanzhong. This shows that the control of fireworks and firecrackers has greatly helped improve the air quality in Xi'an.
From February 4 (New Year's Eve) to February 9 (Friday), Xi'an harvested 1 blue sky, 2 heavily polluted days, and 3 lightly polluted days. On February 5th (June 1), air quality soared from good to severely polluted, with the average PM2.5 concentration rising from 66 micrograms per cubic meter to 236 micrograms per cubic meter.
On New Year's Eve in 2019, the Beijing-Tianjin-Hebei and surrounding areas, the Fenwei Plain, the Yangtze River Delta region, and the Chengdu-Chongqing region have all experienced heavy atmospheric pollution processes. The National Center for Atmospheric Pollution Control Association organized experts in time to analyze and interpret the causes of the pollution process. The meteorological conditions of the 11 cities in the Fenwei Plain are similar to those in Beijing, Tianjin and Hebei, and the surrounding areas. There are inverse temperatures near the ground, and high relative humidity may easily cause local accumulation and secondary conversion of pollutants. In this process, the primary pollutant was PM2.5, and the hourly pollution level in 9 of the 11 cities reached severe or higher.
At 23:00 on New Year's Eve, the air quality index of Xixian New District was 377, which was a serious pollution; Xianyang was 272, which was a serious pollution; Weinan City was 238, which was a serious pollution; Xi'an City was 178, which was a moderate pollution.
Expert analysis believes that the PM2.5 concentration of fireworks during the New Year's Eve in major cities in the Fenwei Plain in 2019 and the contribution of fireworks to PM2.5 are slightly lower than the same period in 2018, of which the PM2.5 concentration and fireworks in New Year's Eve in Xi'an The contribution to PM2.5 is lower than the same period of last year, and the PM2.5 concentration and fireworks emission in Xianyang and Weinan are equivalent to the same period of last year, indicating that some cities in the Fenwei Plain need to further strengthen the control of fireworks emission.