SCIENCE NEWS The eruption of Mt. Redoubt http://www.avo.alaska.edu/ http://geology.com/volcanoes/redoubt/

Atmosphere Layers by Height

What are the distinct properties of the Atmosphere? Temperature Air Pressure Humidity

What is Temperature? The measure of the average kinetic energy of the particles in a material

How is Temperature Measured?

Temperature in the atmosphere decreases when altitude increases What is the relationship between temperature and the atmospheric layers? Temperature in the atmosphere decreases when altitude increases

Temperature InVERSION In the TROPOSPHERE there is an exception. Temperature InVERSION

Over a localize region, an increase in temperature occurs with an increase in altitude.

Effects … FOG

Chicago

What is Air Pressure? Pressure exerted on a surface by the weight of the atmosphere above the surface

How is air pressure measured? Barometer units of millibars (mb)

Air pressure in the atmosphere decreases when altitude increases What is the relationship between air pressure and the atmospheric layers? Air pressure in the atmosphere decreases when altitude increases

Density Remember the candy model? What does the different size candies represent? Density

Density: The mass of a material in a unit volume. In the atmosphere because atoms & molecules become farther apart as altitude increase… the density of air decreases with increasing altitude.

Reflect on pages 289-293 & today’s lecture submit 2 questions HOMEWORK Reflect on pages 289-293 & today’s lecture submit 2 questions

Aurora Borealis and Aurora Australis are Best Observed in Spring SCIENCE NEWS Aurora Borealis and Aurora Australis are Best Observed in Spring Aurora Borealis - Aurora Australis - Northern Lights - Southern Lights The Aurora Page

What is Humidity? The amount of water vapor in the atmosphere at a given location on the Earth’s surface.

1. Relative Humidity 2. Dew Point Commonly described in two ways.. 1. Relative Humidity 2. Dew Point

1. Relative Humidity the amount of water vapor in the air relative to the amount of water vapor needed to reach saturation

EXPRESSED AS A PERCENTAGE Measured by a …

Relative Humidity decreases with increasing temperature.

2. Dew Point expressed as temperature which air must be cooled at constant pressure to reach saturation

Dew Point Chart

Relative Humidity & Dew Point talks about saturation Relative Humidity & Dew Point talks about saturation. What is saturation? A condition where any addition of water vapor to an air mass leads to condensation

Relationship between Temperature, Dew Point & Humidity Activity: Suomi Virtual Museum

Humidity in the atmosphere depends upon on evaporation & condensation What is the relationship between humidity and the atmosphere? Humidity in the atmosphere depends upon on evaporation & condensation

What is released when water vapor condenses? LATENT HEAT

The extra thermal energy contained in water vapor compared to liquid water.

Within Each Layer

Let’s combine all the properties of the atmosphere… altitude, temperature, air pressure, humidity

Review The Troposphere Temperature decreases with altitude Air pressure decreases significantly Weather & Clouds The Stratosphere Temperature increases with altitude Air pressure decreases rapidly Ozone Layer, Weather Balloons & Jet planes

Mesosphere Temperature decreases Air pressure steadily decreasing Meteors burn up & Rounding rockets Thermosphere Temperature increases sharply then steady extreme heat Air pressure negligible Space shuttle Orbits & Auroras

Read Text p 297-303 From these pages formulate two questions HOMEWORK Read Text p 297-303 From these pages formulate two questions