Composition & Structure of the Atmosphere Climate Interactions Table of Contents Composition & Structure of the Atmosphere Ms. De Los Rios 6th Grade

Vocabulary 7.5 Weather is the condition of Earth’s atmosphere at a particular time and place. atmosphere is the envelope of gases that surrounds the planet. water vapor water in the form of a gas. The troposphere is the lowest layer of Earth’s atmosphere. The Stratosphere the second-lowest layer of the Earth’s atmosphere. The Mesosphere- The layer of Earth’s atmosphere immediately above the stratosphere. The Thermosphere- The outermost layer of Earth’s atmosphere. Ionosphere-The lower part of the thermosphere. Exosphere- The outer layer of the thermosphere.

What is the Composition of Earth’s Atmosphere? Weather is the condition of Earth’s atmosphere at a particular time and place. Earth’s atmosphere is the envelope of gases that surrounds the planet. Earth’s atmosphere consists of: Nitrogen Oxygen Carbon dioxide Water vapor, other gases (trace gases) particles of liquids and solids

Gases in the Atmosphere pg. 261-262 Nitrogen The most abundant gas in the atmosphere is nitrogen. It makes up a little more than three fourths (3/4)of the air we breathe. Oxygen Is the second most abundant gas, makes up about 21 percent of the volume. Plants and animals take oxygen from air and use it to release the energy in food. Oxygen is also necessary for fire to burn. Oxygen and nitrogen make up 99 percent of dry air.

Gases in the Atmosphere pg. 262 Carbon dioxide Makes up much less than 1 percent of the atmosphere, but it is essential to life. Plants must have carbon dioxide to produce food. Argon (trace gases) The other one percent is mostly argon, plus other gases in amounts so small that they are described as trace gases.

Composition & Structure of the Atmosphere Gases in the Air Which circle graph shows the correct percentage of gases in the atmosphere? How should each portion of the graph be labeled? What would be a good title for the graph?

Vocabulary 7.5 pg. 262 The composition of dry air Is not really DRY! Air contains water vapor, or water in the form of a gas. Water vapor is invisible. Water vapor it is not the same thing as steam!! Why??? Steam is made up of tiny droplets of liquid water. Clouds form when water vapor condenses out of the air to form tiny droplets of liquid water or crystals of ice. If these droplets become heavy enough, they fall as rain or snow. Air also contains tiny solid and liquid particles of dust, smoke, salt, and chemicals.

Earth’s atmosphere layers Pg. 263 Scientists divide Earth’s atmosphere into 4 main layers. Troposphere Stratosphere Mesosphere Thermosphere Ionosphere Exosphere The layers are classified according to changes in temperature.

Vocabulary 7.5 pg. 264 The troposphere the lowest layer of Earth’s atmosphere. Tropo- means “turning” or “changing.” The layer of the atmosphere in which Earth’s weather occurs. About 12 kilometers thick, it is the thinnest and most dense layer. It contains almost all the mass of the atmosphere. The Stratosphere extends from the top of the troposphere to about 50 kilometers above Earth’s surface. Strato- means “layer” or “spread out.” The 2nd layer of the atmosphere and contains the ozone layer. The lower stratosphere is cold, about –60°C. The upper stratosphere is warmer because the ozone layer absorbs energy from the sun.

Troposphere & Stratosphere

Composition & Structure of the Atmosphere Troposphere and Stratosphere Earth's weather occurs in the troposphere. The stratosphere contains the ozone layer.

Changing Temperatures Composition & Structure of the Atmosphere pg. 265 Changing Temperatures The graph shows how temperatures in the atmosphere change with altitude.

Four Main Layers pg. 266 The Mesosphere The 3rd layer ,Above the stratosphere. Meso- means “middle.” extends from about 50–80 km above Earth’s surface. Temperatures approach –90°C. The layer of the atmosphere that protects Earth’s surface from being hit by most meteoroids. The Thermosphere The outermost layer of Earth’s atmosphere. extends from 80 km above Earth’s surface outward into space with no definite outer limit. It has two layers The lower layer, the ionosphere, extends from about 80–400 km above Earth’s surface. The outer layer, the exosphere, extends from about 400 km outward for thousands of km.

Mesosphere & Thermosphere

Aurora Borealis pg. 266 Particles from the sun strike atoms in the ionosphere near the poles. This causes brilliant light displays called auroras.

Composition & Structure of the Atmosphere Mesosphere and Thermosphere The mesosphere protects Earth’s surface from being hit by most meteoroids. In the thermosphere, the air is thin and you cannot feel heat.