The Leo on Wheels: Tooele Jr. High
Wednesday, January 27, 2010
Blog entry by Analiesa Leonhardt from The Leo on Wheels staff
From January 12-15, The Leo on Wheels visited Tooele Junior High School. While driving through the Tooele Valley in the middle of the afternoon, we could barely see the shore line of the Great Salt Lake and the mountains were nearly blocked by a brownish haze. Here is a photo we took, looking directly at the sun around 3:00pm:
This was not just a typically cloudy or foggy day, but rather the effects of a thermal inversion. This naturally-occurring event happens when the atmosphere’s temperature gradient is “inverted” from its usual state. Anyone who has climbed a mountain in the summertime knows that at higher elevations the air is usually cooler. During an inversion, however, cooler and denser air is trapped at the earth’s surface beneath a high pressure layer of warmer air. The mountains bordering our valley keep this trapped cold air walled in, and because the cooler air is denser it remains in the valley, accumulating water vapor and pollutants. Here is a diagram of what is going on during an inversion.
Pollutants from power plants, factories, vehicle exhaust, and wood-burning stoves that would normally rise and spread with the winds are instead concentrated right along the earth’s surface. Why is this such a concern? The fine particles of matter in the pollution enter our lungs and bloodstream when we breath. The national standard for safe air is set at 35 micrograms of pollutants per cubic meter of air. Since November, however, Salt Lake County has had more than a dozen “red alert” air quality days, meaning that the particulate matter in the air ranges from 151 to 200 micrograms per cubic meter. In this range even healthy people are adversely affected, but those with heart and/or lung disease, older adults, children, and those who are active in the outdoors are at even greater risk.
This was not just a typically cloudy or foggy day, but rather the effects of a thermal inversion. This naturally-occurring event happens when the atmosphere’s temperature gradient is “inverted” from its usual state. Anyone who has climbed a mountain in the summertime knows that at higher elevations the air is usually cooler. During an inversion, however, cooler and denser air is trapped at the earth’s surface beneath a high pressure layer of warmer air. The mountains bordering our valley keep this trapped cold air walled in, and because the cooler air is denser it remains in the valley, accumulating water vapor and pollutants. Here is a diagram of what is going on during an inversion.
Image from National Service Forecast Office
Gratefully, storm systems are moving through our valleys now, churning the air and improving (at least locally) our breathing experience. For more information about current air quality conditions along with information on how you can make a difference, visit the website of Utah Division of Air Quality.
Labels: education, locals, science, The Leo on Wheels, weather
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