DATE: Tuesday, May 1, 2012 SWBAT: explain how the Sun heats the Earth HOMEWORK: none CATALYST: April 30 - May 4 1. What is the temperature of the atmosphere at an altitude of 70 miles? a. -80  C c. 27  C b. -15  C d. 50  C 2. Which of the four atmospheric zones has the smallest range of temperatures? a. the mesosphere c. the thermosphere b. the stratosphere d. the troposphere 3. Which two atmospheric zones show decreasing temperature with increasing altitude? a.the mesosphere and troposphere b.the stratosphere and thermosphere c.the thermosphere and mesosphere d.the troposphere and stratosphere b. -15  C b. the stratosphere a. the mesosphere and troposphere

How does the Sun heat Earth? Tuesday, May 1, 2012

How does the Sun heat Earth? 1. The sun gives off radiation, which travels through space as waves. through space as waves.  This radiant energy provides all of the energy that heats the atmosphere of our energy that heats the atmosphere of our planet. planet. Flashback: What process is occurring in the Sun to release this energy? Nuclear Fusion

How does the Sun heat Earth? 2. This radiant energy reaches Earth. 50% absorbed by the ground 50% absorbed by the ground 20% absorbed by atmosphere 20% absorbed by atmosphere 30% reflected back into space 30% reflected back into space

How does the Sun heat Earth? 3. When the Earth absorbs this energy, it releases it back toward space Sun’s energy Energy emitted by surface

How does the Sun heat Earth? 3.1 Some of energy that is absorbed at the surface is reemitted into space as infrared (IR) waves. What form of heat transfer? RADIATION Sun’s energy IR Waves

How does the Sun heat Earth? FLASHBACK!!! What gases absorb some of this IR radiation as it escapes toward space? GREENHOUSE GASES Infrared Radiation Sun’s energy

How does the Sun heat Earth? 3.2 Some of the absorbed energy is transferred to the air molecules that are directly touching the surface. What form of heat transfer is being used? It’s tricky! CONDUCTION Sun’s energy Conduction & Rising Air Infrared Waves

How does the Sun heat Earth? 4. The hot air molecules at Earth’s surface are then transferred it up to heat the rest of the atmosphere! What form of heat transfer is being used? CONVECTION

How does the Sun heat Earth?  As dense, cool air moves into an area with warm, less dense air, the warmer air is pushed upward.  This movement creates winds.

1. Takeout a new sheet of paper. 2. Draw the following image on the paper. 3. Identify the mode of heat transfer occurring in each of the following sections. IR Rays Continue completing your homework on this page. Read pages & 560 and answer questions 1, 3, & 4 on page 560.