Section 1: Atmospheric Basics Energy is transferred throughout Earth’s atmosphere. K What I Know W What I Want to Find Out L What I Learned

Essential Questions What is the gas and particle composition of the atmosphere? What are the five layers of the atmosphere? How is energy transferred in the atmosphere? Atmospheric Basics Copyright © McGraw-Hill Education

Vocabulary Review New atmosphere troposphere stratosphere mesosphere thermosphere exosphere radiation conduction convection Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Composition Air is a combination of gases, such as nitrogen and oxygen, and particles, such as dust, water droplets, and ice crystals. Copyright © McGraw-Hill Education Atmospheric Basics

Atmospheric Composition Permanent atmospheric gases Earth’s atmosphere consists mainly of nitrogen (78 percent) and oxygen (21 percent). The amounts of nitrogen and oxygen in the atmosphere are fairly constant over time. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Composition Variable atmospheric gases The concentrations of some atmospheric gases are not as constant over time as the concentrations of nitrogen and oxygen. The concentration of water vapor in the atmosphere varies with the seasons, with the altitude of a particular mass of air, and with the properties of the surface beneath the air. During the past 150 years, the concentration of atmospheric carbon dioxide has increased, due primarily to the burning of fossil fuels. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Composition Variable atmospheric gases Molecules of ozone are formed by the addition of an oxygen atom to an oxygen molecule. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Composition Variable atmospheric gases The ozone layer blocks harmful ultraviolet rays from reaching Earth’s surface. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Composition Atmospheric particles Earth’s atmosphere contains variable amounts of solids in the form of tiny particles, such as dust, salt, and ice. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Layers The atmosphere is classified into five different layers: the troposphere, stratosphere, mesosphere, thermosphere, and exosphere. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Layers Troposphere The layer closest to Earth’s surface, the troposphere, contains most of the mass of the atmosphere and is where weather occurs. In the troposphere, air temperature decreases as altitude increases. The tropopause is the altitude at which the temperature stops decreasing. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Layers Stratosphere Above the tropopause is the stratosphere, a layer in which the air temperature mainly increases with altitude and which contains the ozone layer. At the stratopause, air temperature stops increasing with altitude. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Layers Mesosphere Above the stratopause is the mesosphere, in which air temperature decreases with altitude. Temperatures stop decreasing with altitude at the mesopause. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Layers Thermosphere The thermosphere is the layer above the mesopause and contains the ionosphere. Atmospheric Basics Copyright © McGraw-Hill Education

Atmospheric Layers Exosphere The exosphere is the outermost layer of Earth’s atmosphere and can be thought of as the transitional region between Earth’s atmosphere and outer space. Atmospheric Basics Copyright © McGraw-Hill Education

Add link to Interactive Table from p. 284 here. Components of the Atmosphere Concepts In Motion FPO Add link to Interactive Table from p. 284 here. Atmospheric Basics Copyright © McGraw-Hill Education

Visualizing the Layers of the Atmosphere Earth’s atmosphere is made up of five layers. Each layer is unique in composition and temperature. Atmospheric Basics Copyright © McGraw-Hill Education

Add link to Interactive Table from p. 285 here. Visualizing the Layers of the Atmosphere Concepts In Motion FPO Add link to Interactive Table from p. 285 here. Atmospheric Basics Copyright © McGraw-Hill Education

Energy Transfer in the Atmosphere The total energy of the particles in an object due to their random motion is called thermal energy. Atmospheric Basics Copyright © McGraw-Hill Education

Energy Transfer in the Atmosphere Radiation Radiation is the transfer of thermal energy by electromagnetic waves. Thermal energy is transferred from the Sun to Earth by radiation. Atmospheric Basics Copyright © McGraw-Hill Education

Energy Transfer in the Atmosphere Radiation Incoming solar radiation is either reflected back into space or absorbed by Earth’s atmosphere or its surface. Atmospheric Basics Copyright © McGraw-Hill Education

Energy Transfer in the Atmosphere Radiation The rate of absorption for any particular area varies depending on the physical characteristics of the area and the amount of solar radiation it receives. Atmospheric Basics Copyright © McGraw-Hill Education

Energy Transfer in the Atmosphere Conduction Conduction is the transfer of thermal energy between objects when their atoms or molecules collide. Atmospheric Basics Copyright © McGraw-Hill Education

Energy Transfer in the Atmosphere Convection Convection is the transfer of thermal energy by the movement of heated material from one place to another. Atmospheric Basics Copyright © McGraw-Hill Education

Add link to Animation from p. 288 here. Energy Transfer Concepts In Motion FPO Add link to Animation from p. 288 here. Atmospheric Basics Copyright © McGraw-Hill Education

Review Essential Questions Vocabulary What is the gas and particle composition of the atmosphere? What are the five layers of the atmosphere? How is energy transferred in the atmosphere? Vocabulary troposphere stratosphere mesosphere thermosphere exosphere radiation conduction convection Atmospheric Basics Copyright © McGraw-Hill Education