English: A blanket of light gray haze and aerosols hung over Eastern China near the Yellow Sea in mid-November 2020.

On November 13 the Moderate Resolution Imaging Spectroradiometer (MODIS) on board NASA's Aqua satellite acquired a true-color image of the smoky scene. Several areas of Henan, Shanxi, Shandong, Anhui, and Jiangsu provinces were hidden under the haze which is so thick that, in many areas, the land is obscured from view. A river of wind-driven smoke and haze flows eastward over the Yellow Sea.

Regional severe haze creates a serious environmental problem in China, impacting air quality, human and animal health, weather, climate, and has far-reaching impact on the local ecosystems. Severe haze events are frequent, especially in winter when cooler weather can create an air inversion over the region, trapping particulates, smoke, and other pollutants close to the ground. The haze originates from many sources, including the burning of stubble in the agricultural fields or using fire for other land-management practices, industrial and vehicle emissions, and other factors, making for a complex mix of unsightly and unhealthy pollutants that can linger for days or weeks at a time.

The satellite record shows that the skies in this region were clear on November 9, despite widespread agricultural fires. A small area of haze appeared on November 10, but by the next day a huge swath of haze covered China’s east, stretching nearly 1,900 miles from north of Harbin almost to Wuhan. The swath was nearly 500 miles wide. Over the next day the haze thinned and spread further south and north with wind currents. This image captured the small but dense remnant of the event that had lingered over the region for four days.