Fog is a common feature along the West Coast during the summer, but a University of Washington scientist has found that summertime coastal fog has declined since 1950 while coastal temperatures have increased slightly.
Fog formation appears to be controlled by a high-pressure system normally present off the West Coast throughout the summer, said James Johnstone, a postdoctoral researcher with the Joint Institute for the Study of the Atmosphere and Ocean at the University of Washington.
"The behavior of that high-pressure cell is responsible for a lot of the weather phenomena we see on the coast," he said. It can alter water temperature, ocean circulation, surface winds and other factors linked to coastal fog formation.
The fog decline could have negative effects on coastal forests that depend on cool and humid summers, but Johnstone, who presented his findings Dec. 13 at the American Geophysical Union annual meeting in San Francisco, hasn't seen evidence of that yet.
In fact, climate models indicate that coastal fog should be increasing because of global warming, but he believes that is not happening because of strong influence exerted by regional circulation patterns related to the Pacific Decadal Oscillation. That climate phenomenon, centered in the North Pacific, has wide-ranging effects that last for years or even decades rather than for just a year or two.
Article continues: http://www.sciencedaily.com/releases/2010/12/101213121743.htm