Can cold air handle smog?

From the meteorological point of view, the bane of fog and haze is cold air. Compared with smog, the scale of cold air is much larger, and the range of cold air mass is often thousands of kilometers long and the thickness is several kilometers to dozens of kilometers. Removing smog with cold air is equivalent to a tiger bullying a rabbit, and smog is just "seeking light abuse".

When cold air approaches, the upward movement near its front (that is, vertical wind) will bring PM2.5 into the higher atmosphere. Besides vertical wind, there is horizontal wind. The northerly wind will bring clean air to North China (except when there is dust in spring), and it is not excluded that PM2.5 in North China will spread to other areas, making the local air quality worse.

Just like a class on the playground in physical education class, it is scattered to all corners of the school after class, and it may be on different floors, just like PM2.5 is blown to different heights and areas, so the concentration of PM2.5 in unit volume will drop rapidly. In short, cold air came, static conditions were broken, PM2.5 was greatly diluted, and fog and haze dissipated.

Finally, although cold air can blow away fog and haze, fog and haze will appear again in the future, and there will be vomit about fog and haze, and the thinking of preventing fog and haze is far from stopping. We can't just rely on optimism to "strive for self-improvement" psychologically, nor can we just rely on the unreasonable method of "manpower to disperse smog", but the blue sky should never be blown out by cold air alone.