- Slides: 50
Chapter 17 Climate
What is Climate? Climate is the pattern of weather that occurs in an area over many years. It determines the types of plants or animals that can survive, and it influences how people live. Climate is determined by averaging the weather of a region for at least 30 years. Rain forests have a hot, wet climate. (Here you would find beautiful flowers, and plants beneath a canopy of towering trees, variety of exotic birds and frogs. These things all thrive in hot temperature and abundant rainfall. )
Scientist average five things to determine an area’s climate: › temperature › precipitation › air pressure › humidity › number of days of sunshine
Factors that affect the climate of a region: › latitude › landforms › location of lakes › ocean currents
Latitude and Climate (fig 1 p. 484) Regions closer to the equator are the hottest because they receive the most solar radiation (the sun shines almost directly over these areas. This area is called the tropics – the region between latitudes 23. 5 N and 23. 5 S. Next are the temperate zones (23. 5 – 66. 5 N and S). These zones are just above the tropics and just below the topics. Temperatures here are moderate. Most of the U. S is here. Then you have the polar zones (extend from 66. 5 N and 66. 5 S latitude to the poles). Solar radiation hits these zones at a low angle, spreading energy over a large area. Polar Regions are never warm.
Large Bodies of Water (fig 2 p. 485) Large bodies of water can affect the climate of coastal areas by absorbing or giving off heat This causes many coastal regions to be warmer in the winter and cooler in the summer compared to inland areas at similar latitudes. Remember, water heats up and cools down more slowly than land does. (day – cool sea breezes: night – land breezes)
Ocean Currents Warm currents begin near the equator and flow toward higher latitudes, warming the land regions they pass. When the currents cool off and flow back toward the equator, they cool the air and climates of nearby land (coastal lands). Winds blowing from the sea are often moister than those blowing from land causing coastal areas to have wetter climates than places further inland.
Mountains At the same latitude, the climate is colder in the mountains than at sea level. Remember: the sun heats the earth’s surface, the heat then goes back up through the Earth’s atmosphere. Because Earth’s atmosphere gets thinner at high altitudes, the air in the mountains has fewer molecules to absorb heat.
Mountains also affect regional climates. Windward: on the windward side of a mountain range, air rises, cools, and drops its moisture. (green, vegetation) Leeward: on the leeward side of a mountain range, air descends heats up, and dries the land. (desserts are found here)
Cities Large cities affect local climates. Streets, parking lots, and buildings heat up, in turn heating the air. Air pollution traps this heat, creating what is known as the heat- island effect. Temperatures in a city can be 5 degrees C higher than in surrounding rural areas.
Turn to page 487 Section 1 Review Questions (#1 -4) Write the answer in a complete sentence! Keep in your notebook = )
STUDY FOR YOUR QUIZ
Quiz #1 1. 2. 3. 4. 5. 6. _____ is the average weather over a long time. Earth has been _____ in times past. What has a major influence on climate? The ________ is based on studies of temperature and precipitation. The _______ have moderate temperatures. With regard to the Ice Age, what are we in now?
Section 2: Climate Types
Section 2 Vocabulary Turn to page 488 and define new words in your notebook • When you finish read pages 488 -491
Writing your Essay Must be 150 words or more Must contain all 6 facts from your sheet Written or typed(double spaced) 3 paragraphs: › First paragraph – location, average rainfall and temperature › Second paragraph – Vegetation and landscape › Third paragraph – Animals and humans
Oral Presentation No more than a minute You must use all your information you gathered You must be knowledgeable of your biome’s facts You may use note cards (do not read them)
Shoe Box Model Be creative!!!!!! Must contain vegetation, animals, and landforms The more you have…. . THE BETTER = )
Section 2: Climate Types
Classifying Climates Climatologists are people who study climates. They usually use a system developed in 1918 by Wladimir Koppen to classify climates. Climates are classified into six groups: › › › tropical mild dry (semiarid and arid) continental polar high elevation
Adaptations Koppen observed that the type of climate in a region determines the vegetation found there. Ex. ) cacti are found in desserts not rain forests. An adaptation is any structure or behavior that helps an organism survive in its environment. Once adapted to a particular climate, organisms may not be able to survive in other climates. Organisms have structural and behavioral adaptations that help them survive in particular climates.
- Structural adaptations Some organisms have body structures that help them survive in certain climates. Fur on mammals insulates them from cold temperatures.
Cacti have a thick, fleshy stem that holds water. The waxy stem covering prevents water inside the cactus from evaporating. They also have spiny leaves, called needles that further reduce water loss.
- Behavioral Adaptations Hibernation – behavioral adaptation for winter survival in which an animal’s activity is greatly reduced, its body temperature drops, and body processes slow down. Factors that trigger hibernation: cooler temperature, shorter days, and lack of adequate food.
Bees cluster together in a tight ball to conserve heat in cold weather Desert snakes hide under rocks during hot sunny days. At night when its cooler, they slither out and search for food. Desert turtles and lizards obtain the moisture they need from their food. A lungfish will survive periods of intense heat by entering an inactive state called estivation. When the weather gets hot, the water evaporates and he burrows into mud and covers itself in a leathery mixture of mud and mucus.
How climate changes affects you……. . In hot weather you have adaptations that help you adjust to climate: › hot weather you sweat cooling you down › cold weather you shiver to help your body stay warm
Put a star by these numbers: #5 #10 #11 #18 #19 #23 ***Quiz tomorrow: October 6 th ***Copy the questions and answers in your notes!
STUDY FOR YOUR QUIZ!!!!!!!
1. 2. 3. 4. 5. 6. Quiz #2 Deforestation is not a ______ adaptation. The ________ in the polar regions is hard to adapt to. ____ have opposite extremes of day and night temperatures. Changes in the Earth’s orbit may have caused what? How is the angle of sunlight a factor in climate? An animal that hibernates does what?
Turn to page 492 in your science book Define Section 3 terms in your notebook Read Section 3 quietly at your desk ***I will be checking notebooks!!!!!!
Section 3: Climatic Changes
Seasons are short periods of climatic change caused by changes in the amount of solar radiation an area receives. Because the Earth is tilted; different areas of Earth receive changing amounts of solar radiation throughout the year.
The tropics receive fairly constant solar radiation near the equator; therefore the tropics do not have much seasonal temperature change. (dry and rainy weather) The middle latitudes, or temperate zones, have warm summers and cool winters. Spring and Fall are usually mild. The high latitudes, polar zones, have great differences in temperature and number of daylight hours. During the summer the sun doesn’t set for nearly six months in the North Pole. During that same time, the sun never rises in the South Pole.
El Nino – a climatic event that involves the tropical Pacific Ocean and the atmosphere. El Nino can affect weather patterns. It can alter position and strength of one of the jet streams.
This changes atmospheric pressure off California and wind precipitation patterns around the world. Causing: droughts in Australia and Africa, monsoons in Indonesia and storms in California. The opposite of El Nino is La Nina. During La Nina, the winds blowing across the Pacific are stronger than normal, causing warm water to accumulate in the western Pacific. May cause droughts in southern U. S. and excess rainfall in Northern U. S. (p. 494 & 495)
Read pages 494 and 495 in your Science book! Study El Nino & La Nina
What causes Climatic Change? Catastrophic events, including meteorite collisions and large volcanic eruptions, can affect climate over short periods of time, such as a year or several years. › These events add solid particles and liquid droplets to the upper atmosphere, which can change climate. Short- or Long – term changes in solar output, which is the amount of energy given off by the Sun › Changes in Earth’s movements in space affect climate over many thousand of years.
Climate Changes Atmospheric solids and liquids: solid/liquid particles are put in the atmosphere naturally by volcanic eruptions, soot from fires, and wind erosion; and by humans through automobile exhaust and smokestack emissions. (these effect our climate) › These small particles block so much radiation they can cool the planet. › In cities, particles put into the atmosphere as pollution can change the local climate.
Sunspots can also affect climate: the more sunspots the hotter the climate. Earth’s tilt changes about every 41, 000 years. Some scientist hypothesize that the change in tilt affects climate.
Crustal Plate Movement The movement of Earth’s crustal plates, continents and oceans, affects the transfer of heat on Earth, which in turn affects wind and precipitation patterns.
Climate Changes Today Greenhouse Effect – natural heating process that occurs when certain gases in Earth’s atmosphere trap heat and then radiates the heat back toward Earth. This keeps the Earth warmer than it would be otherwise. Natural Greenhouse gases in Earth’s atmosphere: water vapor, methane, and carbon dioxide. (without these gases, life would not be possible) Like Mars, Earth would be too cold
High level of carbon dioxide could cause Earth to be too warm, like Venus. Over the past 100 years, the average global surface temperature on Earth had increased by about. 6 degrees C. this increase in temperature in known as Global Warming. (Carbon dioxide has increased by 20%)
Human Activities Burning fossil fuels and removing vegetation increase the amount of carbon dioxide in the atmosphere. Because carbon dioxide is a greenhouse gas, it might contribute to global warming. Each year the amount of carbon dioxide in the atmosphere increases. Deforestation – destroying and cutting down trees As trees grow they take in carbon dioxide
New page: Label: Chapter 17 Section 3 Review Page 502 #1 -5 Write the answer only, in complete sentences!
STUDY FOR YOUR QUIZ!!!!
Quiz #3 1. 2. 3. 4. 5. 6. 7. 8. 9. The tilt of the Earth’s axis causes _______. A _____ climate may have year round changes in seasons. What helps keep the Earth warm for living things? _____ may be caused by deforestation. Planting trees can help reduce ______ in the atmosphere. ____ causes ocean temperatures near Peru to increase. ______ is released when fossil fuels are burned. ________ might cause planetary cooling. In winter at the North Pole there is what?