Images
July 12, 2010 - Saharan Dust over the Lesser Antilles
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The MODIS on the Terra satellite captured this image of Saharan Dust over the Lesser Antilles on July 1, 2010. The Lesser Antilles are on the eastern edge of the Caribbean Sea. As you can see from this image from 2009, Saharan dust can travel all the way across the Atlantic from Africa.
This is thanks to a hot, dry, dusty layer of air known as the Saharan Air Layer. Extreme daytime heating of the Sahara creates instability in the lowest layer of the atmosphere, lofting dust particles into the air. The dust-laden air layer continues warming as it travels westward across the Sahara. As the Saharan Air Layer moves off the west coast of Africa, it passes over a cooler, wetter layer of air. This temperature inversion (air usually cools with altitude) prevents mixing, enabling the dust layer to travel across the ocean intact. Across the Atlantic, dust brings problems and benefits: respiratory illness and coral bleaching, but also rich soils.
Image Facts
Satellite:
Terra
Date Acquired: 07/01/2010
Resolutions:
1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit:
Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
The MODIS on the Terra satellite captured this image of Saharan Dust over the Lesser Antilles on July 1, 2010. The Lesser Antilles are on the eastern edge of the Caribbean Sea. As you can see from this image from 2009, Saharan dust can travel all the way across the Atlantic from Africa.
This is thanks to a hot, dry, dusty layer of air known as the Saharan Air Layer. Extreme daytime heating of the Sahara creates instability in the lowest layer of the atmosphere, lofting dust particles into the air. The dust-laden air layer continues warming as it travels westward across the Sahara. As the Saharan Air Layer moves off the west coast of Africa, it passes over a cooler, wetter layer of air. This temperature inversion (air usually cools with altitude) prevents mixing, enabling the dust layer to travel across the ocean intact. Across the Atlantic, dust brings problems and benefits: respiratory illness and coral bleaching, but also rich soils.
Image Facts
Satellite:
Terra
Date Acquired: 07/01/2010
Resolutions:
1km ( B), 500m ( B), 250m ( B)
Bands Used: 1,4,3
Image Credit:
Jeff Schmaltz, MODIS Land Rapid Response Team, NASA GSFC
