Temperature Inversions the cause of the smoggy brown haze.

--Atmospheric Convection-- REVIEW of CONVECTION The sun’s thermal energy heats up the Earth surface. Warm air has more energy, causing the molecules to excite and spread out (expansion). The expansion of warm air makes it less dense then colder air, which causes it to rise (dense, cold air sinks while less dense, hot air rises). This movement of energy is an example of CONVECTION. (It is what makes the wind blow!) The temperature of the air naturally decreases as it gets further away from the surface of the Earth. --Atmospheric Convection--

Colder air is found higher in the atmosphere. What is the normal atmosphere like? Colder air is found higher in the atmosphere. Warm air is found lower in the atmosphere, and grows colder as altitude increases.

Temperature Inversion Basic Definition for Temperature Inversion A temperature Inversion is a weather condition where the temperature of the air increases as it gets further away from the surface of the Earth. This is the opposite of a normal weather condition.

What is the difference between normal atmosphere conditions and temperature inversion? When a temperature inversion occurs, the warmer air coming from the Earth’s surface slows or stops while the cooler air stays below (capping). (It happens when the Earth’s surface no longer radiates heat.) Normal Warm Air Cool Air

Surface Temp Inversions -- Occurs at the Earth’s surface. -- Most common type of inversion. -- Typically occurs at nighttime because the sun is not warming the Earth. -- Influenced by wind, weather, and length of night.

Causes of Temperature Inversion A stable layer of warm air high in the atmosphere Calm Atmosphere Lots of Moisture Clear Skies Long Nights High Pressure Systems

Effects of Temperature Inversion Effects of temperature inversion include decreased air quality, fewer thunderstorms, lower temperatures, and flattened cloud appearance. Examples

How does temperature inversion influence air quality? As pollutants from vehicles, fireplaces, and industry are emitted into the air, the inversion traps these pollutants near the ground, leading to poor air quality.

105’ 38°F 105’ 38°F 64’ 40°F 64’ 40°F 32’ 40°F 32’ 40°F 16’ 41°F 16’ 41°F 8’ 41°F 8’ 41°F

Surface Inversion Temperature Profile 105’ 43°F 64’ 36°F 32’ 32°F Cold air drainage down a slope Surface Inversion

Surface Temperature Inversions occur close to the Earth’s surface. Temperature Inversions most often occurs at nighttime. Temperature Inversion is warm air trapping cool air beneath it. One of the biggest effects of Temperature Inversion is poor air quality (SMOG!!). Review Points End

Works Cited NOAA, Retrieved January 29, 2009, from National Forecast Weather Service Web site: http://www.wrh.noaa.gov/slc/climate/TemperatureI nversions.php (2007). What is a Temperature Inversion?. Retrieved January 29, 2009, from WeatherQuestions.com Web site: http://www.weatherquestions.com/What_is_a_te mperature_inversion.htm (2008, Dec 2). Temperature Inversions Impact Air Quality. Retrieved January 29, 2009, from AirNow.gov Web site: http://www.airnow.gov/index.cfm?action=static.inv ersions