Pollution Reduces Winter Precipitation

  • Released Tuesday, December 9, 2003
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In winter, moist air flows off the ocean and rises over the hills downwind of a coastal city, dropping its rain and snow mainly as it ascends the hills. As pollution from the city is pushed into the clouds by the hills downwind of the city, it interferes with droplet formation in the clouds as observed by NASA's satellites. The smaller cloud droplets convert more slowly into precipitation. Instead of precipitating, much of the water in the clouds evaporates, reducing the net rainfall downwind of the urban area by up to 15% to 25% on a seasonal basis. First is the unpolluted case.

This animation shows what winter precipitation is like when pollution is not involved.

This animation shows what winter precipitation is like when pollution is involved.

Credits

Please give credit for this item to:
NASA/Goddard Space Flight Center Conceptual Image Lab

This page was originally published on Tuesday, December 9, 2003.
This page was last updated on Wednesday, May 3, 2023 at 1:56 PM EDT.