Satellite cloud images help you understand the weather: What does sandstorm weather look like in the eyes of Fengyun satellites?

Although the grains of sand are small, when they gather together...

You are at risk of "eating dirt"!

How to capture sandstorm weather?

Satellite remote sensing technology

It is the most effective means to monitor sandstorm weather in real time

Fengyun-4 geostationary meteorological satellite

A monitoring image can be obtained every five minutes

Therefore, monitoring of sandstorm weather

Almost reaching the standard of quasi-real time

So, on the satellite cloud map

What does sandstorm weather look like?

It might look like this↓

On March 15, 2021, my country experienced the strongest sandstorm in nearly 10 years, which is the yellow area in the picture.

It may also be like this↓

From April 19 to 21, 2022, the largest-scale strong wind and dust weather since the beginning of spring occurred in northern my country. The picture shows the dust situation monitored by FY-4A on April 21

Why do these sandstorms occur?

Simply put, there needs to be sand, dust and wind.

There are four major sandy areas and eight major deserts (sand sources) in my country.

In favorable wind conditions (including wind speed, wind direction, wind duration, etc.)

Under these conditions, dust can be removed from the source of the sand.

Transported by wind to any place downstream

At the same time, the dry and rainy weather in the early stage,

Warmer weather and rising temperatures

It is also one of the conditions for the formation of sandstorms.

On April 15, 2021, sandstorms occurred in central Inner Mongolia

If the source of dust is a material condition

Strong wind is the power source

So is the lower atmosphere stratified in

"Unstable state" is also an important factor affecting sandstorm weather

Because unstable thermal conditions are conducive to increased wind speed

Makes dust fly higher and farther

Thereby carrying more dust downstream

This formed a sandstorm

The latter two can determine the intensity of sandstorm weather.

Movement path and duration

What kind of weather system is this?

Will it lead to sandstorms?

You must know a concept - extratropical cyclone

Extratropical cyclone

A cyclone is a large-scale vortex that occupies three dimensions and has a lower central air pressure than the surrounding areas at the same altitude. Based on the main geographical areas where cyclones form and move, they can be divided into two categories: temperate cyclones and tropical cyclones.

From a structural point of view, a temperate cyclone is a cold system with baroclinic properties. Due to the intersection of cold and warm air, a temperate cyclone usually appears with a front, so it is also called a "frontal cyclone". The weather brought by a temperate cyclone is quite diverse, including common storms, fog, dust, severe convection and blizzards.

In the picture, the red arrow points to the cyclone head, where gray-yellow dust can be seen.

Dust weather this week

It is also formed by the influence of the eastward-moving frontal cyclone cloud system.

Starting from the morning of April 20, 2022, sandstorms first appeared in southern Mongolia and western Inner Mongolia. Subsequently, the sandstorm area expanded to the southeast. As of this morning, sandstorms have appeared in central and southeastern Inner Mongolia, central and northern Ningxia, northern Shaanxi, northern Shanxi and Beijing.

The time sequence chart of sandstorm monitoring by FY-4A meteorological satellite shows that since 10:00 on April 20, sandstorms have affected southern Mongolia. Affected by the west-northwest wind, the sandstorm range has expanded to the southeast, affecting central and western Inner Mongolia from the afternoon to evening of the 20th, and affecting central Inner Mongolia and northern North China from the early morning to the morning of the 21st. In the morning, it affected northern Shanxi, western and northern Hebei, Beijing and other places. Photo courtesy: Liu Qinghua and Song Wanjiao

The FY-4A meteorological satellite dust monitoring duration chart shows that the dust in central and western Inner Mongolia lasted the longest, up to 8-10 hours. Photo courtesy: Liu Qinghua and Song Wanjiao

In addition, in extratropical cyclones

"Mongolian cyclones" are more common

It has a great impact on the weather in northern my country

Mainly characterized by strong winds, dust and rainfall

The most prominent

On March 28, 2021, the Fengyun-4 meteorological satellite monitored the movement of sand and dust in real time. It can be clearly seen in the northeast of Inner Mongolia that the frontal cyclone cloud system has entered the occlusion stage.

What should you do when you see sandstorms?

Be prepared for wind and sand prevention in advance, and close doors and windows in time. Carry masks, scarves and other dust-proof items when traveling, and drive slowly; pay attention to the sealing of precision instruments; and secure fences, scaffolding and temporary structures that are easily blown by the wind.

Content from: National Satellite Meteorological Center