Energy Transfer in the Atmosphere Lesson 2.1 Energy Transfer in the Atmosphere

Vocabulary radiation stability conduction temperature inversion convection

Essential Questions How does energy transfer from the Sun to Earth and the atmosphere? 1 How are air circulation patterns within the atmosphere created? 2

Sunny Destinations Explore Activity The Sun sends out enormous amounts of energy. Solar energy is produced through nuclear reactions in the Sun’s core. Once this energy reaches the solar surface, it takes only 8 minutes, traveling at a speed of 300,000 km/s, to reach Earth. What evidence can you provide that energy from the Sun actually reaches Earth’s surface? Write or illustrate your ideas in the space below.

Energy from the Sun Earth through the process of radiation. Radiation is the transfer of thermal energy by electromagnetic waves. Ninety-nine percent of the radiant energy from the Sun consists of visible light, ultraviolet light, and infrared radiation. NASA/JPL

Energy on Earth As the Sun’s energy passes through the atmosphere, some of it is absorbed by gases and particles, and some of it is reflected back into space. As a result, not all the energy coming from the Sun reaches Earth’s surface.

Radiation Balance The Sun’s radiation heats Earth. So, why doesn’t Earth get hotter and hotter as it continues to receive radiation from the Sun? There is a balance between the amount of incoming radiation from the Sun and the amount of outgoing radiation from Earth.

The Greenhouse Effect Earth’s atmosphere acts like a blanket that protects our planet from extreme temperature and radiation. Some gases that make up the atmosphere influence how much radiation escapes and is absorbed by the atmosphere. These gases, called greenhouse gases, act like the glass of a greenhouse.

The Greenhouse Effect

Thermal Energy Transfer There are three types of thermal energy transfer — radiation, conduction, and convection. All three occur in the atmosphere. Recall that radiation is the process that transfers energy from the Sun to Earth’s systems.

Circulating Air Heat is the transfer of thermal energy from a region of higher temperature to a region of lower temperature. In the atmosphere, thermal energy can be transferred by radiation, conduction, and convection. James Brunker/Alamy

Mini-Assessment 1. How does thermal energy move between objects? It moves from objects of lower mass to objects with higher mass. A It moves from objects of lower temperature to objects with higher temperature. C It moves from objects of higher mass to objects with lower mass. B It moves from objects of higher temperature to objects with lower temperature. D CORRECT

Mini-Assessment 2. Which gas is NOT an efficient greenhouse gas? helium A carbon dioxide C CORRECT methane B water vapor D

Mini-Assessment 3. How is energy transferred when objects are in contact? conduction A latent heat C CORRECT convection B radiation D

Mini-Assessment 4. In the image below, which type of heat transfer is represented by the number 3? conduction A convection B latent heat C radiation D CORRECT

Mini-Assessment 5. In what form does most solar radiation reach Earth? infrared light A ultraviolet light C microwaves B visible light D CORRECT