1. Journal #27 What were your results from yesterday? Why did you get the results you did?

3. Variations in Temperature Radiation from the sun does not heat Earth equally at all places at all times. A slight delay occurs between the absorption of energy and an increase in temperature. To change the temperature of the atmosphere, Earth’s surface must absorb energy for a length of time. For a similar reason, the warmest hours of the day are mid-late afternoon even though solar radiation is most intense at noon.

4. Factors that Influence Atmospheric Temperature Latitude Surface features Time of year Time of day

5. Latitude Latitude is the primary factor that affects the amount of solar energy that reaches any point on Earth’s surface. Because Earth is a sphere, the sun’s rays do not strike all areas at the same angle

6. Latitude Where sunlight hits the Earth’s surface over a larger area and is spread out, the suns rays are less intense. Therefore, the energy that reaches the equator is more intense than the energy that strikes the poles. So, the average temperatures are higher near the equator than near the poles.

7. Seasons Temperature varies seasonally because of the tilt of Earth’s axis. As Earth revolves around the sun once each year, the position of the Earths surface that receives the most intense sunlight changes. For part of the year, the Northern hemisphere is tilted toward the sun and receives more direct sunlight. During this time, the temperatures are their highest What do you think happens for the Southern hemisphere?

9. Light and Latitude Demonstration Hold a flashlight so that the beam shines directly on a piece of white paper Outline the beam of light Move the flashlight at an angle and redraw the beam. 1. How does the area of the direct beam differ from the area of the angled beam? 2. How does this exercise illustrate how latitude affects incoming solar radiation?

10. Water in the Air Because water vapor stores heat, the amount of water in the air affects the temperature of an area. Areas of higher elevation contain less water vapor and carbon dioxide to absorb heat. These areas will be warm during the day and cooler at night. What about desert areas?

11. Water on the Surface Land areas close to large bodies of water have more moderate temperatures. These areas are cooler during the day and warmer at night than inland regions. The reason is that water heats up and cools down slower than land does, so the temperature of water changes less than the temperature of land.

13. Wind The wind patterns also affect temperature. A region that receives winds off the ocean waters has more moderate temperatures than does a similar region in which the winds blow from the land.

14. Conduction The molecules in a substance move faster as they become heated. The fast moving molecules cause other molecules to move faster: Collisions between the particles result in the transfer of energy, which warms the substance. The transfer of energy as heat from one substance to another by direct contact is called conduction. Solid substances that are close together make good conductors.

15. Conduction Conduction heats only the lowest few centimeters of the atmosphere, where air comes into direct contact with the warmed surface of the Earth. Can you think of other examples of Conduction

16. Convection The heating of the lower atmosphere is primarily the result of convection. Convection is the process by which air, or other matter, rises or sinks because of differences in temperature. Convection occurs when gases or liquids are heated unevenly.

17. Convection The continuous cycle in which cold air sinks and warm air rises warms Earth’s atmosphere evenly. Because warm air is less dense than cooler air, warmer air exerts less pressure than the same volume of cooler air. Recall the pressure lab we did with the coke can? So the atmospheric pressure is lower beneath a mass of warmer air. As cool air moves in, the warmer air gets pushed upward. These pressure differences create winds