The difference between floating dust and sand blowing is that sand blowing is formed by local or nearby dust, while floating dust mostly comes from far away (or it may be formed by dust still floating in the air after sand blowing); More importantly, when blowing sand, the wind is strong and the air is unstable, while the condition of floating dust is little or no wind.

1, floating dust

On the day of ups and downs, dust and fine sand will float in the air evenly, and the visibility is poor, and the horizontal visibility is less than 10.0km. There are two reasons for the appearance of floating dust. First, before and after the cold air passes through the border, when there is no wind or no wind, it is spread by distant dust through the high-altitude airflow. The second is caused by dust floating in the air after sand blowing or sandstorm weather.

Step 2 blow sand

Because the wind blows up the dust on the ground, the air is quite turbid, and the horizontal visibility is between 1.0km and 10.0km. Sand blowing is due to the dust blown up locally or nearby, which reduces the visibility, makes the sky cloudy and makes the wind stronger. In northern spring and summer, cold air passes through the mirror or the air is unstable.

dust storm/devil

The cause of sandstorm is similar to blowing sand, but the visibility is low and the wind is strong. Often accompanied by strong convection or thunderstorms. Because the strong wind blows up a lot of dust on the ground, the air is quite turbid, and the horizontal visibility is even less than 1 km. According to the visibility, sandstorms are divided into three grades: sandstorms (visibility 0.5km~ less than1.0 km); ); Strong sandstorm (visibility 0.05km~ less than 0.5 km); Extremely strong sandstorm (visibility less than 0.05km).

Mr. Lu Xun once wrote: "The wind is covered with yellow sand, and the sun is yellow in Gui Xiang." The "cinnamon yellow" sunshine was originally the "desert dust day" written by frontier fortress poets.

In this weather, you must take protective measures. Because it is likely to induce allergic diseases, epidemics and infectious diseases. Under normal circumstances, people's nasal cavity, lungs and other organs will have a certain filtering effect on dust, but the fine dust caused by bad weather phenomena such as sand blowing and sandstorm is too much and too dense for our filtering system to cope with.

Even healthy people, if they inhale dust for a long time, will have uncomfortable symptoms such as cough and asthma, which will lead to the outbreak.