Why is there frequent dusty weather in most parts of the north this year
Our reporter Guo Jingyuan
Since March 27, most of northern China has been plagued by sand and dust.
What caused the dusty weather process this time?
Why has sand and dust weather been frequent in most parts of the north this year?
The reporter interviewed Zhang Tao, chief forecaster of the Central Meteorological Observatory, and Rao Xiaoqin, senior engineer of the Environmental Meteorological Center of the Central Meteorological Observatory.
"The strong dust storm weather this time was mainly due to the Mongolian cyclone and the cold high pressure, which carried the surface dust to high altitudes and then transmitted it over long distances. The dynamic conditions for the sanding and transmission of the dust were good." Zhang Tao analyzed that last winter Since then, Mongolia, the central and western regions of Inner Mongolia, and the northwestern region of China have continued to have less precipitation, and the snow cover area is relatively small; since February this year, the temperature in these areas has been significantly higher, the surface soil has become looser, and the sand emission conditions are better. It is the material basis for the formation of sand and dust weather.
Compared with the severe sandstorm weather process from March 14th to 18th, what are the characteristics of this sandstorm weather process?
Rao Xiaoqin said that the intensity of the sand and dust weather process this time is slightly weaker, the impact of sandstorms is easterly, the range of strong sandstorms is relatively smaller, and the transmission range of flying sand or floating dust to the south is slightly smaller, and the duration is relatively short.
From the perspective of the cause of formation, the two processes were caused by the Mongolian cyclone generated at the same location.
Judging from the conditions of sand emission, the strong sandstorm weather from March 14 to 18 was mainly due to the cold and high pressure transporting sand and dust from Mongolia to our country, and the large amount of wind caused the particularly large amount of sand emission in Mongolia.
This time the Mongolian cyclone moved slightly to the southeast, but it superimposed the local sandstorm in Inner Mongolia.
In terms of intensity, the dust concentration in the previous round was higher.
Data show that since the beginning of this year, most parts of the north have experienced 6 large-scale sand and dust weather processes. This weekend, the re-emergence of sand and dust processes is the seventh round of sand and dust weather processes.
Two of them were strong sandstorms, which was the most severe sandstorm in the past 15 years.
So, why is there more sand and dust this spring?
Zhang Tao explained that there are many factors that cause sandstorms, one is bare ground, the other is long-term dryness with little rain, and the third is the impact of strong winds caused by cold air.
"Since March, we have monitored that the average temperature from Mongolia to the central and western regions of Inner Mongolia is about 6°C higher than usual. This has led to warmer sand sources in the above-mentioned areas, and the soil is prone to thawing and loosening, and it is easy to be in the cold air zone. Under the influence of the strong wind, the sand will rise and form a dusty weather." Zhang Tao said.
Meteorological experts reminded that according to current weather trends, in the coming week, most parts of northern my country will have sand and dust weather, especially in the northwest, Inner Mongolia and other places, where there are still more sand and dust days. People need to pay attention to weather forecasts to reduce unnecessary Travel and take relevant protections.
Our reporter Guo Jingyuan