Images
February 12, 2025 - Thick Aerosol Haze over India and Bangladesh
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An extremely thick and broad blanket of aerosol pollution spread across India and Bangladesh in early February 2025. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this true-color image of the region on February 10. At that time, the gray haze was so thick that it obscured much of the land south of the Himalaya from view, with the rest partially obscured.
Haze is common in this region and the result of a complicated mixture of pollutants, including smoke from agricultural fires, automobile exhaust, coal-fired industries, and coal used to heat homes, to mention a few. Tiny particles suspended in the air (aerosols) reflect light in various directions and, when aerosols are heavy, these optical properties result in gray haze.
Haze frequently occurs in northern India and Bangladesh, especially in the winter, although this density is unusual. In addition to the multiple sources of aerosols in the region, the region is subject to temperature inversions, which trap haze and pollution close to the ground, allowing it to accumulate.
Under normal conditions, air near the ground is warmer than the air above it. Warm air rises and carries pollution with it. The pollution disperses when it is mixed with cooler air high above the ground. During the Himalayan winter, cold air rushes down the mountains onto the plain. This makes the air near the ground cooler than the air above it, essentially trapping a pocket of cold air over the plain. This inversion also allows haze and pollution to build up in the pocket of cold air and keep it from dispersing.
Image Facts
Satellite:
Terra
Date Acquired: 2/10/2025
Resolutions:
1km (314.2 KB), 500m (745.5 KB), 250m (1 MB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
An extremely thick and broad blanket of aerosol pollution spread across India and Bangladesh in early February 2025. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite acquired this true-color image of the region on February 10. At that time, the gray haze was so thick that it obscured much of the land south of the Himalaya from view, with the rest partially obscured.
Haze is common in this region and the result of a complicated mixture of pollutants, including smoke from agricultural fires, automobile exhaust, coal-fired industries, and coal used to heat homes, to mention a few. Tiny particles suspended in the air (aerosols) reflect light in various directions and, when aerosols are heavy, these optical properties result in gray haze.
Haze frequently occurs in northern India and Bangladesh, especially in the winter, although this density is unusual. In addition to the multiple sources of aerosols in the region, the region is subject to temperature inversions, which trap haze and pollution close to the ground, allowing it to accumulate.
Under normal conditions, air near the ground is warmer than the air above it. Warm air rises and carries pollution with it. The pollution disperses when it is mixed with cooler air high above the ground. During the Himalayan winter, cold air rushes down the mountains onto the plain. This makes the air near the ground cooler than the air above it, essentially trapping a pocket of cold air over the plain. This inversion also allows haze and pollution to build up in the pocket of cold air and keep it from dispersing.
Image Facts
Satellite:
Terra
Date Acquired: 2/10/2025
Resolutions:
1km (314.2 KB), 500m (745.5 KB), 250m (1 MB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
