Download Inversions - Shawnee Beeler

By: Shawnee Beeler
Photo Courtesy: Scott G. Winterton/Deseret News
What is an inversion?
Definition: a
reversal of the
normal decrease
of air
temperature with
altitude, or of
water
temperature with
depth.
•Utah is said to see
one or two periods of
Inversions during the
winter months a year.
•Inversions occur here
because the
mountains surround all
four sides of the Salt
Lake Valley.
Inversion over the Salt Lake Valley
Meteorological Conditions
•Cold Temperatures
•No Breezes
•Why?
•Because the air isn’t
moving, the pollution
also has nowhere to go
and begins to build up.
•It is held in place
beneath a layer of warm
air.
•Which creates a layer
of smog making it
difficult to breathe
1. The winter sun, low in
the sky supplies less
warmth to the Earth’s
surface.
2. Warmer air aloft acts as
a lid and holds cold air
near the ground.
3. Pollution from wood fires
and cars are trapped by
the inversion.
4. Mountains can increase
the strength of valley
inversions.
Temperature impacts air quality?
•
Surface Temperature plays a
major role in air quality.
•
Pollutants from vehicles, fireplaces, &
industry emit into the air, the inversion
keeps pollutants near the ground.
• Strong inversions will confine pollutants to a
shallow concentrated yellowish layer, leading
to higher air pollution levels
Photo Courtesy: Tom Smart, Deseret Morning News
Inversion Suppresses Convection
• An inversion can
also suppress
convection by
acting as a “cap” or
“lid”.
• If the cap is broken
for any reasons,
convection of any
moisture present
can then erupt into
violent
thunderstorms!
Storm drives away
Inversion
•This is a picture of what an
Inversion looks like on the left
•On the right is a photo from a
week later after a huge winter
storm
•The storm drove out the
inversion and now the air is more
sustainable to breathe.
Photo Courtesy: Trent Nelson & Chris
Detrick
Layer of Smog
•Inversions lead to pollution, such as smog, being
trapped close to the ground, which can cause harm
to the air we breath.
Why is it called an inversion?
• The condition is
called an inversion
because it is a
reverse of normal
air patterns.
• Cool air above,
warm air below
Ways to prevent Winter Air Pollution
• Drive less. Walk, carpool, bike, or take
the bus instead. Combine errands into one
trip.
• Avoid Idling. Save gas and reduce
engine wear by limiting idling to less than a
minute.
• Reduce fireplace use. Heating by
fireplace is a very inefficient form of heat. If
you have an option, choose electric,
natural gas, solar, or EPA certified wood
stove to heat your home.
• Keep your car well maintained and
check your tire pressure monthly. Save
money on gas and reduce emissions
associated with poorly maintained vehicles.
•An inversion will linger until
wind or a storm comes
through.
•The “typical” period of an inversion
ranges from a few days to a week,
although there have been occasional
inversions that lasted 2 to 3 weeks
Works Cited
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http://www.nytimes.com/2013/02/24/us/utah-a-nature-lovers-haven-is-plagued-by-dirtyair.html?_r=0
http://www.airquality.utah.gov/clean_air/archive/inversion.htm
http://watchingtheworldwakeup.blogspot.com/2008/11/big-scramble-another-hybridoak-and-dog.html
http://www.deq.co.pima.az.us/New/newsrelease/WinterAirPollutionSeason.html
(arizona)
http://www.mnn.com/local-reports/utah/local-blog/smog-settles-on-salt-lake-city
http://www.chrisdetrick.com/blog/2007/02/slc-inversion.htm