Warm Up 3/7/08 Earth receives energy from the sun through what method of heat transfer? a. radiation c. convection b. conduction d. none of the above Which process involves mass movement within a substance? a. radiation c. conduction b. convection d. reflection All matter is composed of atoms or molecules that have energy of motion, also known as ____. a. solar energy c. potential energy b. radiation d. kinetic energy Answers: 1) a. 2) b. 3) d.

Temperature Controls Chapter 17, Section 3

Why Temperatures Vary A temperature control is any factor that causes temperature to vary from place to place and from time to time Because variations in the angle of the sun’s rays and length of daylight depend on latitude, they are responsible for warmer temperatures in the tropics and colder temperatures toward the poles Factors other than latitude that exert a strong influence on temperature include heating of land and water, altitude, geographic position, cloud cover, and ocean currents

Concept Check List three factors that influence temperature. Latitude, differential heating of land and water, altitude, geographic position, cloud cover, ocean currents

Land and Water Land heats more rapidly and to higher temperatures than water Land also cools more rapidly and to lower temperatures than water Temperature variations, therefore, are considerably greater over land than over water The Southern Hemisphere shows smaller annual temperature variations, due to it having more water than the Northern Hemisphere

Mean Monthly Temperatures for Vancouver and Winnipeg

Variation in Annual Mean Temperature Range with Latitude

Geographic Position A coastal location where prevailing winds blow from the ocean onto the shore (a windward coast) experiences considerably different temperatures than does a coastal location where the prevailing winds blow from the land to the ocean (a leeward coast) The windward coast will experience all of the moderating effects of the ocean, cool summers and mild winters The leeward coast will have a more continental pattern because winds do not carry the ocean’s influence to shore Mountains may act as a barrier for a windward coast, and the opposite side will not receive the moderating effect of the ocean

Monthly Temperatures for Eureka, CA and New York City

Monthly Temperatures for Seattle and Spokane, WA

Altitude, Cloud Cover and Albedo Two cities at the same latitude may have much different temperatures due to altitude, with the higher city’s temperature being colder Albedo – the fraction of total radiation that is reflected by any surface Many clouds have a high albedo, and therefore reflect a significant portion of the sunlight that strikes them back to space During the day, clouds will keep the temperatures cooler by not allowing as much solar energy to get through During the night, clouds act as a blanket by absorbing outgoing radiation and reradiating it back to the surface The effect of cloud cover is to reduce the daily temperature range

Monthly Temperatures for Quito and Guayaquil, Ecuador

Clouds Reduce Daily Temperature Range

Concept Check Why do many clouds reflect a significant amount of sunlight back to space? Clouds reflect a significant amount of sunlight back to space because of their high albedos.

World Distribution of Temperature Isotherms – lines that connect points that have the same temperature The isotherms on a world isothermal map generally trend east and west and show a decrease in temperatures from the tropics toward the poles

World Distribution of Mean Temperature for January

World Distribution of Mean Temperature for July

Assignment Read Chapter 17 (pg. 476-493) Do Chapter 17 Assessment #1-30 (pg. 499-500) STUDY for Chapter 17 Quiz!

Cool Down How do the heating of land and water differ? Land heats and cools more rapidly and to greater temperature extremes than water does. Why do some coastal cities experience a moderation of temperature from water, while other do not? Some coastal cities are influenced more strongly from prevailing ocean winds than others are. What is one new thing you learned today? Explain.