Major dust storm engulfs northern China, Beijing

A major dust storm is blowing across northern China today, May 4, 2017, turning the sky yellow, dragging down air quality and causing travel disruptions. The storm is reaching capital Beijing, where weather authorities issued this year's first dust and sand alert (blue).

Visibility dropped as low as 1 km (0.62 miles) in many parts of Bejing today, as a major dust storm from Mongolia hit large swathes of northern China, Xinhua reports.

Most monitoring stations in the city showed PM₁₀ readings of more than 1 000 µg/m³ (micrograms per cubic meter) as of 04:00 local time. Later in the morning, the reading dropped to around 900. The World Health Organization air quality guidelines (AQG) recommend 50 µg/m³ of PM₁₀ as a 24-hour mean and 20 µg/m³ as an annual mean.

According to Reuters, official data from the Beijing government showed average readings of PM_2.5 had risen to 630 µg/m3 in parts of the city by Thursday morning, though it dropped slightly later in the day. WHO's guideline for PM_2.5 is 25 µg/m³ as a 24-hour mean and 10 µg/m³ as an annual mean.

Particulate matter (also called particle pollution) contains microscopic solids or liquid droplets so small that they can cause serious health problems if inhaled. Particles less than 10 micrometers in diameter pose the greatest problems because they can get deep into lungs and bloodstream.

Officials urged residents of affected regions to avoid outdoor activities as much as possible, especially old people and children. Many pedestrians in downtown Beijing were later seen wearing protective masks and bandanas.

The Beijing Capital International Airport said 48 flights were canceled early Thursday, including six international routes in Asia and Russia.

The dust storm is expected to persist in Beijing, as well as Gansu, Hebei, Heilongjiang, Jilin, Shaanxi and Shanxi provinces through the end of Thursday and into Friday, May 5.

The meteorological phenomenon called Asian Dust, also known as yellow dust, yellow sand, yellow wind or China dust storms, regularly affects much of East Asia, especially during the spring months. 

Originating in the deserts of northern China, Kazakhstan and Mongolia, these clouds of dust and sand are then carried eastward where they can reach as far as Japan, Russian Far East and sometimes even the United States.

Credits: Left – NASA Terra/MODIS, Right – NASA/NOAA Suomi NPP/VIIRS

Featured image: Dust storm engulfs Beijing, China on May 4, 2017. Credit: CGTN