Dust storms commonly occur across Asia in springtime. In addition to natural-color imagery, Jethva tracks dust and smoke using satellite measurements of the UV aerosol index. That was the case in Beijing, where the high concentration of particles caused air quality to reach well into the “hazardous” level of the Air Quality Index. In addition to the unusual magnitude and early season timing of the event, Jethva noted that it is uncommon for dust storms to grow so large so fast. News reports called for the dust storm to gradually weaken through the rest of the week.