Skip navigation    
The Why Files Cool Science Images
      Browse archived CSI's:
      biology Earth & Space Environment Health Physical Science Technology
Ship Tracks
Clouds swirl over blue ocean.You knew roaming freighters and oil tankers made waves, but…clouds? It’s true. Large ships are not a significant source of pollution, but they spray a mist of sulfur dioxide into the air in the exhaust from their smokestacks. The particles float into the atmosphere, creating peculiar cloud formations that carry more water than ordinary clouds. They may also be less likely than the garden-variety clump of cumulus clouds to make rain.

Because scientists don’t fully understand the role clouds play in global climate, understanding how they are formed and shaped is a burgeoning area of study. In recent years, researchers have been most interested to know how human activities -- on air, land and sea -- change natural patterns.

This image of clouds hovering over the northern Pacific was captured in 2002 by the Moderate-resolution Imaging Spectradiometer (MODIS) aboard NASA’s Terra satellite.


  Back to The Why Files