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December 1, 2024 - Aerosols over the Arabian Sea
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On November 26, 2024, the Moderate Resolution Imaging Spectroradiometer (MODIS) acquired a true-color image of a thick haze hanging over the Arabian Sea.
The haze, which is so thick that it hides the ocean below from view, is a result of aerosol pollution. Aerosols are tiny bits of solid particles and liquid droplets. They can be a variety of substances and range in size from a few nanometers—less than the width of the smallest viruses—to several tens of micrometers—about the diameter of human hair.
Haze often forms over the Arabian Sea, especially in winter when temperature inversions keep haze close to the Earth’s surface. Inversions occur when cold air gets trapped under a layer of warm air. Usually, air high in the atmosphere is cooler than air near Earth’s surface. Warmer air near the surface rises, allowing pollutants from the surface to disperse in the atmosphere. Because cold air cannot rise above the warmer air, pollution builds as long as the temperature inversion lasts.
It’s likely that several pollutants contribute to the gray haze visible in this image. Satellite imagery shows that the haze appeared to move in pulses from northern Pakistan and India, where it accumulated along the southern face of the Himalayas, southward down the Indo-Gangetic plain to reach the Arabian Sea. This portion of the gray haze would contain a combination of industrial emissions, auto emissions, burning of coal for warmth, and the burning of biomass that occurs seasonally as farmers clear cropland.
In addition, the haze likely contains dust from sand-filled regions of Pakistan, just north of the Arabian Sea. Dust storms are common contributors to haze in this region.
Image Facts
Satellite:
Aqua
Date Acquired: 11/26/2024
Resolutions:
1km (1004.5 KB), 500m (1.5 MB), 250m ( B)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
On November 26, 2024, the Moderate Resolution Imaging Spectroradiometer (MODIS) acquired a true-color image of a thick haze hanging over the Arabian Sea.
The haze, which is so thick that it hides the ocean below from view, is a result of aerosol pollution. Aerosols are tiny bits of solid particles and liquid droplets. They can be a variety of substances and range in size from a few nanometers—less than the width of the smallest viruses—to several tens of micrometers—about the diameter of human hair.
Haze often forms over the Arabian Sea, especially in winter when temperature inversions keep haze close to the Earth’s surface. Inversions occur when cold air gets trapped under a layer of warm air. Usually, air high in the atmosphere is cooler than air near Earth’s surface. Warmer air near the surface rises, allowing pollutants from the surface to disperse in the atmosphere. Because cold air cannot rise above the warmer air, pollution builds as long as the temperature inversion lasts.
It’s likely that several pollutants contribute to the gray haze visible in this image. Satellite imagery shows that the haze appeared to move in pulses from northern Pakistan and India, where it accumulated along the southern face of the Himalayas, southward down the Indo-Gangetic plain to reach the Arabian Sea. This portion of the gray haze would contain a combination of industrial emissions, auto emissions, burning of coal for warmth, and the burning of biomass that occurs seasonally as farmers clear cropland. In addition, the haze likely contains dust from sand-filled regions of Pakistan, just north of the Arabian Sea. Dust storms are common contributors to haze in this region.
Image Facts
Satellite:
Aqua
Date Acquired: 11/26/2024
Resolutions:
1km (1004.5 KB), 500m (1.5 MB), 250m ( B)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
