Images
January 10, 2026 - Haze Over China
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Thick haze shrouded China’s Sichuan Basin in early January 2025, obscuring the land from view. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this true-color image on January 9.
While the air in the northern portion of the Basin was colored gray with dense aerosols (small particulate matter suspended in air), low cloud (fog) covered the southern section. The fog appears to hover over the lower layer of haze. To the north and west, snow topped the peaks of the Qionglaishan Mountains, where the air was crisp and clear.
On the day this image was acquired, IQAir reported that PM2.5 measurements reached 181 micrograms per cubic meter of air. Fine, airborne particulate matter (PM) that is smaller than 2.5 microns (about one thirtieth the width of a human hair) is considered dangerous because it is small enough to enter the passages of the human lungs. Most PM2.5 aerosol particles come from the burning of fossil fuels and biomass (wood fires and agricultural burning). The World Health Organization considers PM2.5 to be safe when it is below 25.
Haze in this region tends to worsen in the winter, when cold, heavy air traps pollutants near the surface. In this case, the haze was likely trapped in the Sichuan Basin by a temperature inversion. Normally, air is warmest near the surface of the Earth. Occasionally, a mass of warm air will move over cooler air so that the atmosphere actually warms with altitude. Since the cool air does not have the energy to rise through the warm air, vertical circulation slows and air becomes trapped near the surface.
Any pollutant that enters the air gets trapped as well, and haze builds up over time. Temperature inversions often form in basins and valleys because surrounding higher-elevation land helps contain cold air. Daily satellite images of the region show that haze has persisted across the Sichuan Basin since late December 2025.
Image Facts
Satellite:
Aqua
Date Acquired: 1/9/2026
Resolutions:
1km (811.9 KB), 500m (2.4 MB), 250m (3.6 MB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
Thick haze shrouded China’s Sichuan Basin in early January 2025, obscuring the land from view. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite acquired this true-color image on January 9.
While the air in the northern portion of the Basin was colored gray with dense aerosols (small particulate matter suspended in air), low cloud (fog) covered the southern section. The fog appears to hover over the lower layer of haze. To the north and west, snow topped the peaks of the Qionglaishan Mountains, where the air was crisp and clear.
On the day this image was acquired, IQAir reported that PM2.5 measurements reached 181 micrograms per cubic meter of air. Fine, airborne particulate matter (PM) that is smaller than 2.5 microns (about one thirtieth the width of a human hair) is considered dangerous because it is small enough to enter the passages of the human lungs. Most PM2.5 aerosol particles come from the burning of fossil fuels and biomass (wood fires and agricultural burning). The World Health Organization considers PM2.5 to be safe when it is below 25.
Haze in this region tends to worsen in the winter, when cold, heavy air traps pollutants near the surface. In this case, the haze was likely trapped in the Sichuan Basin by a temperature inversion. Normally, air is warmest near the surface of the Earth. Occasionally, a mass of warm air will move over cooler air so that the atmosphere actually warms with altitude. Since the cool air does not have the energy to rise through the warm air, vertical circulation slows and air becomes trapped near the surface.
Any pollutant that enters the air gets trapped as well, and haze builds up over time. Temperature inversions often form in basins and valleys because surrounding higher-elevation land helps contain cold air. Daily satellite images of the region show that haze has persisted across the Sichuan Basin since late December 2025.
Image Facts
Satellite:
Aqua
Date Acquired: 1/9/2026
Resolutions:
1km (811.9 KB), 500m (2.4 MB), 250m (3.6 MB)
Bands Used: 1,4,3
Image Credit:
MODIS Land Rapid Response Team, NASA GSFC
