What's the difference between sandstorms in the north and floating dust in the south?
Status: floating dust, suspended in the air; Sandstorms, strong winds or strong winds swept the dust and rolled in.
Content: Floating dust is mainly fine dust; Besides dust, sandstorms have bigger particles.
Source: Most of the dust comes from the strong wind or airflow in the northern desert.
These are our intuitive impressions and superficial understanding. Over the years, people have had to deal with floating dust and sandstorms frequently, so it is necessary to know more about them.
According to the authoritative explanation, dust is spread by high-altitude airflow in the distance before and after cold air passes through the border, when there is no wind or the wind is small (the wind speed is less than or equal to 3 meters per second). There is also fine dust suspended in the air after the sandstorm, and the horizontal visibility of floating dust is only 10 km. When there is a sandstorm, the wind is stronger, the dust is more, the air is more turbid, and the horizontal visibility is even less than 1 km.
Whether floating dust or sandstorm is harmful to human life and natural ecology. First of all, it does harm to people's respiratory organs. A lot of dust greatly reduces the defense function of people's respiratory organs, which in turn affects the health of the lungs. High-altitude airflow will also bring distant germs and increase the possibility of people getting sick.
When it comes to floating dust and sandstorms, we have to mention "smog". It is an indicator of the content of various suspended particles in the atmosphere, which is particularly harmful to people's health, especially PM2.5, and smog often lasts for a long time, sometimes for more than a week.
And sand and fog. Sand blowing doesn't necessarily come from far away, and local strong winds can also blow up dust, but this kind of sand blowing is small in scope and short in time. As for "fog" and "smoke", people are sometimes a little hard to distinguish. Fog usually begins in the morning, and the moisture in the air is relatively large, and the color is whiter than fog. The fog is gray, the visibility in the dense fog is extremely low, and the expressway is closed.
Understanding the basic knowledge of these natural phenomena can help us understand, adapt and transform nature. In sandstorm and floating dust weather, we should do a good job of protection to reduce the losses caused by disasters.