Bellwork March 1, 2007 Define the following words: Page 434 Define the following words: Page 434 –Atmosphere –Troposphere –Ionosphere –Ultraviolet Radiation (U.V. Radiation) –Ozone Layer –Chlorofluorocarbon (CFC’s)

Chapter 15: Earth’s Atmosphere

What is the Atmosphere? The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. The atmosphere surrounds Earth and protects us by blocking out dangerous rays from the sun. Is a mixture of gases that is layered and becomes thinner until it gradually reaches space. Is a mixture of gases that is layered and becomes thinner until it gradually reaches space. Insulates the Earth. Insulates the Earth.

78% Nitrogen 78% Nitrogen 21% Oxygen 21% Oxygen ~3% Water Vapor ~3% Water Vapor 0.93% Argon 0.93% Argon 0.04% Carbon Dioxide 0.04% Carbon Dioxide trace amounts of other gases trace amounts of other gases Composition of Earth’s Atmosphere

Layers of the Atmosphere Divided into five different and distinct layers. Divided into five different and distinct layers. Lower layers include the troposphere and stratosphere Lower layers include the troposphere and stratosphere Upper layers are the mesosphere, thermosphere and exosphere. Upper layers are the mesosphere, thermosphere and exosphere. Page 436

Lower Layers Troposphere Troposphere Stratosphere Stratosphere

Troposphere Where we study, eat, sleep, and play. Where we study, eat, sleep, and play. Lowest of Earth’s atmospheric layers. Lowest of Earth’s atmospheric layers. Contains 99% of the water vapor and 75% of atmospheric gases. Contains 99% of the water vapor and 75% of atmospheric gases. Layer in which clouds and weather occur. Layer in which clouds and weather occur.

Stratosphere ~ 10 km (6mi) to 50 km (30mi) above Earth’s Surface ~ 10 km (6mi) to 50 km (30mi) above Earth’s Surface Contains Ozone (O 3 ) Layer Contains Ozone (O 3 ) Layer Temperature increases with altitude. Temperature increases with altitude.

Upper Layers Mesosphere Mesosphere Thermosphere Thermosphere Exosphere Exosphere Page 437

Mesosphere From Stratosphere to 80 km (50mi) above surface. From Stratosphere to 80 km (50mi) above surface. Temperature decreases with altitude. Temperature decreases with altitude. Layer in which most meteors will burn up. Layer in which most meteors will burn up.

Ionosphere Layer of electrically charged particles. Layer of electrically charged particles. Contained within the mesosphere and thermosphere. Contained within the mesosphere and thermosphere. Allows radio waves to travel across the country. Allows radio waves to travel across the country. Pg 437

Thermosphere Extends to from mesosphere to 500km Extends to from mesosphere to 500km Contains the Auroras Contains the Auroras Thickest of the layers Thickest of the layers Temperature varies greatly based on solar energy. Temperature varies greatly based on solar energy. Can heat up to 1,500°C or higher Can heat up to 1,500°C or higher

Exosphere Outermost layer extending to 800 km. Outermost layer extending to 800 km. Where satellites and shuttles orbit the Earth. Where satellites and shuttles orbit the Earth. Contains very few molecules Contains very few molecules

Ozone Layer Contained within the stratosphere. Contained within the stratosphere. It helps to protect us from the sun’s rays. It helps to protect us from the sun’s rays. Located km above us. Located km above us. Made of ozone (O 3 ). Made of ozone (O 3 ). Destroyed by CFC’s. Destroyed by CFC’s. Hole in the ozone layer is increasing each year. Hole in the ozone layer is increasing each year. When the ozone layer disappears there will be more cases of skin cancer. When the ozone layer disappears there will be more cases of skin cancer. Student’s Created

Assignment Draw the layers of the atmosphere. Draw the layers of the atmosphere. Label each layer with the following: Label each layer with the following: – Name – Range (distance from Earth’s Surface) – Characteristics – Temperature Range (Page 439)