In May 2017, a cold front pushing across northern China spurred a major dust storm that darkened skies throughout the region.
On May 3, 2017, the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured an image of several large plumes of dust streaming east from the Gobi Desert. The next day, the Visible Infrared Imaging Radiometer Suite (VIIRS) on Suomi NPP captured an image (below) showing skies thick with dust across much of northeastern China. Notice that cyclonic atmospheric circulation had sucked dust into and above the clouds. (Read this story to learn more about why the presence of dust and smoke above clouds interests climate scientists.)
Air quality in several large cities in northern China deteriorated rapidly after the dust arrived. In Beijing, air quality sensors at the U.S. embassy in Beijing saw the air quality index (AQI) rise from 95 (moderate) at 3:00 a.m. on May 4 to 503 (beyond hazardous) just three hours later. At noon on May 4, the AQI level in Beijing rose as high as 621. AQI values of 0 to 50 are considered healthy. Values between 300 and 500 are considered hazardous.
References and Further Reading
- CNN (2017, May 4) Sandstorm pushes Beijing smog off pollution charts. Accessed May 4, 2017.
- NASA OMPS (2017, May 5) Gobi Desert Dust Storm Moves Across China. Accessed May 4, 2017.
- Scientific American (2014, May 20) Mysterious Childhood Disease Spread by Dust Storms. Accessed May 4, 2017.
- South China Morning Post (2017, May 4) Over 50 Beijing flights cancelled or delayed as sandstorms hit northern China. Accessed May 4, 2017.
- Zhang, X. et al. (2016) A Systematic Review of Global Desert Dust and Associated Human Health Effects. Atmosphere, 7 (12).
NASA image by Jeff Schmaltz, LANCE/EOSDIS Rapid Response. Caption by Adam Voiland.
- Aqua - MODIS
- Suomi NPP - VIIRS