Is it true that Beijing has 36 sunny days and 32 non-heating seasons?
"Blue sky dominates the screen" and "smog-free month" are frequently used words by netizens to describe the weather in Beijing recently. Many citizens feel that this winter in Beijing is different from previous years, with more blue skies and better air. The latest data obtained by reporters from the Municipal Environmental Protection Bureau yesterday showed that in the 36 days from November 15 to December 20, when the heating season entered, Beijing had 32 days with excellent air quality, with an air compliance rate of 89%, and PM2 The average concentration of .5 is only 38 micrograms/cubic meter, which is comparable to non-heating season! So far this autumn and winter, there have only been four heavily polluted days, which is more than half the number in previous years.
PM2.5 concentration is almost the same as during the non-heating season
In previous years, during the heating season, there would be smog every now and then. Since autumn and winter this year, Beijing has only experienced 4 days of heavy pollution, especially After entering the heating season, there was only one day of heavy pollution. During the same period in history, there were an average of seven or eight days of heavy pollution, and two days were at the highest level of serious pollution.
Wang Xin, an engineer at the Municipal Environmental Protection Monitoring Center, said that there are only a handful of heavy pollution cases in autumn and winter this year, and the intervals between heavy pollution are relatively long. From the perspective of the public, the air quality is good.
Data show that the most recent heavy pollution occurred on December 2, followed by 18 consecutive days of good air, including 15 days of first-level excellent weather. Moving forward further, there was a period of heavy pollution on November 6, and then there were two days from October 26 to 27. But these times, the PM2.5 concentration was around 200 micrograms/cubic meter, which is relatively mild among heavy pollution. "Such air quality is unimaginable during the heating season in previous years." Wang Xin said.
The reporter learned that since the beginning of the heating season as of December 20, the average concentration of PM2.5 in the city was only 38 micrograms/cubic meter. Wang Xin said that if you just take out a random monthly average concentration value during the non-heating season, it will be almost at this level. During the same period in the past four years, this value averaged 93 micrograms/cubic meter.
From the perspective of full-year data, the number of days with good air quality this year has reached 218, an increase of 26 days from 192 days last year; the number of days with heavy pollution dropped from 35 days last year to 21 days, a decrease of 14 days.
Stronger winds help dissipate pollutants
The improvement of air quality is the result of "God's help" and "people's efforts".
According to reports, this winter Beijing has more frequent cold air activities, less rain, and is relatively dry. These factors are not conducive to the formation of haze, and the meteorological conditions are generally favorable. Data shows that from December 1 to 19 this year, the average wind speed in Beijing reached 2.31 meters/second, which was greater than the 2.12 meters/second in the same period in 2015 and 1.58 meters/second in 2016. Meteorological experts said that the wind is strong and the air diffusion conditions are relatively good, which is conducive to the reduction of fog and haze. In the case of relatively frequent cold air, coupled with the gradual progress of air pollution control work in Beijing, Tianjin and Hebei and other places in recent years, the probability of blue skies in Beijing in December this year is higher.
The control effect of "scattered pollution" is obvious
The key to improving air quality still relies on "people's efforts." As the "Ten Atmospheric Measures" and the five-year clean air action plan continue to advance, this autumn and winter, under the unified arrangement of the Ministry of Environmental Protection, the city has taken another action to comprehensively control air pollution in autumn and winter, and each district has taken turns to "break up the atmosphere". The special law enforcement action on "pollution control" can be said to be unprecedented in its efforts to reduce emissions.
This year's various pollution reduction measures, especially the control of coal-burning and "scattered pollution" enterprises, are directly linked to the decline in sulfur dioxide and PM2.5 concentrations. So far, the city's sulfur dioxide has dropped by 20% this year, and PM2.5 has also dropped by 18.6% compared with the same period last year, which is a very obvious decline. At the same time, the improvement of air quality is also the release of the benefits of the regional governments' concerted efforts to reduce emissions and the various pollution control and emission reduction measures adopted by Beijing for many years.
In addition, as the air quality continued to be good in December, as of December 20, the average concentration of PM2.5 this year has dropped by 1 microgram/cubic meter compared with the statistics in November, and is currently at 57 Micrograms/cubic meter level. According to the five-year clean air action plan, by the end of 2017, the city’s PM2.5 concentration will drop to about 60 micrograms/cubic meter.