Powerful winds swept northeast out of China on April 14, 2005. The normally invisible air is colored by dust or haze, or possibly a combination of both, in this Moderate Resolution Imaging Spectroradiometer (MODIS) image, collected by NASA’s Terra satellite. Particles such as those seen on the wind in this image are called aerosols. These small airborne particles can have a huge impact on the environment, threatening a range of things from human health to global climate.
Aerosols are generated in almost every part of the world from a variety of sources including the burning of fossil fuels, fires, dust storms and volcanoes. In the atmosphere, aerosols can alter cloud formation. Clouds form when water molecules coalesce on particles. These tiny seeds grow as more and more water gathers around the particle, merging with other seeds until a large cloud is formed. When a large number of aerosols fill the air, water molecules have more places to land. The result is a bright cloud, made of many smaller particles too small to fall as rain.
In this image, the most obvious band of aerosols stretches from the southern tip of China’s Shandong Peninsula, over the Yellow Sea, across North Korea, and over the Sea of Japan. Smaller streamers of dust or haze blow across the Korea Bay, north of the larger plume, and cloud the air to the south of the plume.
NASA image created by Jesse Allen, Earth Observatory, using data obtained from the MODIS Rapid Response team.
- Terra - MODIS