The second sandstorm in two weeks hit Beijing and Tianjin on Sunday, dyeing the skyline yellow and plunging air quality readings to severely polluted.
Although Mongolia was still the largest source of this latest sandstorm, sand from North China also played a part. Experts said that the lower density and smaller size of this sandstorm, compared with the previous one roughly two weeks ago, was a result of the shelterbelts, set up in North China's Inner Mongolia Autonomous Region, that helped reduce the amount of dust and prevented sand from drifting in.
The storm was accompanied by ferocious winds. The city experienced gusts of force 7 to 8, and gusts in mountainous areas soared to levels of force 8 to 10.
According to a statement by the National Forestry and Grassland Administration (NFGA), this storm swept across 13 province-level regions in China, spanning an area of 1.8 million square kilometers and affecting 240 million people.
China's Central Meteorological Observatory activated yellow sandstorm warnings on Saturday morning.
The NFGA said that the reason why sandstorms now frequently hit Beijing and Tianjin is that a continuous dry climate in Mongolia and northwestern China tends to loosen soil, which forms sand and dust, and easily follows the development of air convection and the exchange of air flows.
While temperatures in Mongolia and northwestern China were significantly higher, precipitation was lower and the surface had gradually thawed, making it easier for dust particles to drift, analysts said.