Aerosol particles are formed in smoke from all kinds of fires, including beach bonfires, forest fires, and cigarette smoke. Smaller fires and cigarette smoke do not produce enough particles to have a large effect on clouds or regional air quality, but do reduce the air quality immediately around them.
However, forest fires, especially large ones like the 2007 San Diego and 2008 Los Angeles wildfires, can produce a large number of condensed aerosol particles that can make the sky look dark and hazy. These particles travel with the strong winds that are present during wildfires and can be transported from the land out over the ocean. If there are enough particles, the plume can even be large enough to be seen by satellites in space.
Aerosol particles from fires can also help form clouds by acting as cloud seeds. Just as dew forms on blades of grass, water vapor in the atmosphere needs something to condense on to make a cloud. When these particles are emitted into the atmosphere by larger fires, the water vapor can condense on them and form a cloud.
Scientists at Scripps Institution of Oceanography at UC San Diego are studying the chemistry of aerosol particles measured all over the world to learn more about how they help make clouds.
--Lelia Hawkins, Scripps graduate student, Climate, Atmospheric Sciences, Physical Oceanography division