All the smoke over Philadelphia recently from that wildfire in Canada got me thinking (a dangerous habit, I know)…What's the difference between haze and smog?
Haze forms when fine particles of dust or salt disperse through
the atmosphere. The individual particles making up haze are so tiny
that you cannot see them with the naked eye-but when put together,
they give distant objects a "washed-out" look. As climatologists
like to put it, haze can "diminish horizontal visibility and
give the atmosphere a characteristic opalescent appearance that subdues
all colors." Commonly though, anything that makes the atmosphere
look "hazy" (opalescent, washed-out) is generally described
as a type of haze.
Smog is not really made up of dust or salt, but it is commonly
referred to as a type of haze-even by scientists. The word's origins,
from way back in 1905, come from a combination of "smoke"
and "fog." Smog happens when the gasses from your car's
tailpipe or your factory's smokestack mix with water vapor in the
atmosphere, and then react with sunlight, creating a particularly
nasty form of "haze." The technical definition of smog
developed in recent years is "a photochemical haze caused by
the action of solar ultraviolet radiation on atmosphere polluted
with hydrocarbons and oxides of nitrogen."
Smog is most common in warm, windless cities with heavy traffic,
but it can also form in the 'burbs and even rural areas. The Grand
Canyon, for instance, has had significant smog problems, as have
border crossings and other national park areas open to automobiles.
One way to distinguish between smog and naturally-occurring haze
is by color. Natural haze is typically white, gray or even blue.
Smog is almost always yellowish or brown in color. Neither phenomenon
is all that pleasant, but smog, being a form of human-made air pollution,
is certainly worse.
|
|
To watch our videos online, you need Real Player. Don't have Real Player?
Download it here for free.
