Name: Date: LAB: Climate Adapted from Exploration in Earth Science, The Physical Setting, United Publishing Company, Inc

Transcription

1 Name: Date: LAB: Climate Adapted from Exploration in Earth Science, The Physical Setting, United Publishing Company, Inc Introduction: Climatology is concerned with long-term patterns of weather. Climate is a composite of weather factors that affect an area over many years. While an area s climate can be a product of several factors, usually only one or two exert a major influence. In this activity, you will identify factors, from those listed below, that are primarily responsible for producing the climate for selected locations. Objective: You will learn to identify different climate zones using the climate ratio and the effects of latitude, planetary winds, elevation, mountain ranges, and large bodies of water on climate and determine the climate patterns of a region. Factors that Influence Climate Temperature Precipitation (Moisture) 1. Latitude - As latitude increases, the average yearly temperature decreases 2. Nearness to Centers of Large Landmasses - Locations in temperatures, both between day and night and seasonally. 3. Nearness to Large Bodies of Water - Large bodies of water have a moderating effect on the temperatures of coastal areas, producing low temperature ranges, both between day and night and seasonally. 4. Location Relative to Large Mountain Ranges - Windward sides of mountain ranges are cooled, while leeward sides are warmed. 5. Elevation - As elevation increases, the average yearly temperature decreases. 6. Ocean Currents - Ocean currents tend to warm temperatures of eastern coastal areas and cool temperatures of western coastal areas. 1. Latitude - Belts of low pressure centered at latitudes of 0º and 60º N and S produce generally heavy precipitation. Belts of high pressure centered at 30º N and S produce dry climates; sometimes even deserts. 2. Nearness to Centers of Large Landmasses - Locations near the center of a large landmass tend to have dry climates. 3. Nearness to Large Bodies of Water - Areas near large bodies of water tend to have higher than average precipitation, especially areas on the leeward side of the water. 4. Location Relative to Large Mountain Ranges - Windward sides of mountains tend to receive higher than average precipitation, while leeward sides receive lower than average precipitation. 5. Prevailing Wind Direction - Wind direction determines the windward and leeward sides of both mountain ranges and bodies of water. Part A Using the table of factors that influence climate, answer the following questions which refer to the diagram on page 3. The diagram represents an imaginary continent on the Earth that is surrounded by water. The arrows indicate the direction of the prevailing winds. Two large mountain ranges are also indicated. Points A, B, and E are located at sea level; C and D are in the foothills of the mountains; F is high in the mountains.

2 1. What factor would cause location F to have a colder yearly climate than any other location? 2. What three factors would cause location E to have the greatest annual rainfall? 3. Which location, C or D, would you expect to have the greater rainfall? Explain your answer. 4. Which location, A or B, would you expect to have the greater temperature range? Explain your answer. 5. Location A is in the center of a large desert. What factor could account for its low annual precipitation? 6. What three factors would cause the climate of location D to be cooler than at location B?

3 Imaginary Continent on Earth

4 Part B Climate zones are based on the ratio between precipitation (P) and potential evapotranspiration (E p ), and the effect of latitude, planetary winds, elevation, mountain ranges, and large bodies of water on climate. Potential evapotranspiration (E p ) is how much water evaporates in an area. This ratio between precipitation (P) and potential evapotranspiration (E p ) is called the climate ratio: CLIMATE RATIO = P/E P 1. Using the 6 climographs provided, calculate the P/E p ration for each location in the space provided below. Calculations: Find one area on the map on the previous page that best fits each climographs and write in the number of the climograph at the location. Refer to the diagrams on Global Winds and Pressure Belts, and Ocean Currents on the next page and the Factors that Influence Climate on the first page to help you.

5

6 Part C The climate is the average conditions of temperature and moisture (rainfall and humidity) over a long period of time. Not only are the average temperature and rainfall figures significant, but so are seasonal variations in the two factors. Reading Comprehension: Read the article below on Koppen Climate Classification System and answer the questions that follow (in complete sentences) to better understand the map you will be using later in this lab. Koppen Climate Classification System By Matt Rosenberg, About.com Guide Various attempts have been made to classify the climates of the earth into climatic regions. One notable, yet ancient and misguided example is that of Aristotle's Temperate, Torrid, and Frigid Zones. However, the 20th century classification developed by German climatologist and amateur botanist Wladimir Koppen ( ) continues to be the authoritative map of the world climates in use today. Introduced in 1928 as a wall map co-authored with student Rudolph Geiger, the Koppen system of classification (overview map) was updated and modified by Koppen until his death. Since that time, it has been modified by several geographers. The most common modification of the Köppen system today is that of the late University of Wisconsin geographer Glen Trewartha. The modified Koppen classification uses six letters to divide the world into six major climate regions, based on average annual precipitation, average monthly precipitation, and average monthly temperature... (click the links for a map of each classification) A for Tropical Humid B for Dry C for Mild Mid-Latitude D for Severe Mid-Latitude E for Polar H for Highland (this classification was added after Köppen created his system) Each category is further divided into sub-categories based on temperature and precipitation. For instance, the U.S. states located along the Gulf of Mexico are designated as "Cfa." The "C" represents the "mild midlatitude" category, the second letter "f" stands for the German word feucht or "moist," and the third letter "a" indicates that the average temperature of the warmest month is above 72 F (22 C). Thus, "Cfa" gives us a good indication of the climate of this region, a mild mid-latitude climate with no dry season and a hot summer. While the Koppen system doesn't take such things as temperature extremes, average cloud cover, number of days with sunshine, or wind into account, it's a good representation of our earth's climate. With only 24 different subclassifications, grouped into the six categories, the system is easy to comprehend. Koppen's system is simply a guide to the general climate of the regions of the planet, the borders do not represent instantaneous shifts in climate but are merely transition zones where climate, and especially weather, can fluctuate. 1. What the three basic criteria are used to determine climate zones? 2. How many sub-classifications are there?

7 3. Explain what this statement means: The borders do not represent instantaneous shifts in climate but are merely transition zones where climate, and especially weather, can fluctuate. 4. What climate zone is the majority of the US classified as? The map below shows climate areas of North America based upon how the factors of temperature and rainfall determine the vegetation of an area. Vegetation types are an important indication of the local climate. How does this system characterize the climate of Boonville? (look to find where Boonville is on the map and use the key to determine what each letter stands for) The next page of this activity shows a map of an imaginary continent. Letters A through H show locations of eight geographic locations. Each location matches one of the graphs below the map and one of the paragraphs that start on page 8. To complete this activity, carefully tread each of the eight paragraphs on page 8. Pick the letter from the map on the next page that best shows the location that matches the paragraph. Label the paragraph with the correct letter and also label the graph on the next page that best matches the paragraph and the map location. The first paragraph will show you how it works.

8 C

9 C Although this is a mid latitude climate, the prevailing winds have crossed a major mountain range. There is little rainfall here because the air has dropped its moisture on the windward side of the mountains. Because it is far inland, there are large seasonal variations in temperature. (Note how this description matches the map and the graph on the previous page) Due to its high latitude, This location receives weak insolation. The sun is never high in the sky. Winters are bitter cold while summers are very cool. In a zone of prevailing high pressure, the air is often descending and is consequently low in humidity. Although the ground is usually snow covered, there is very little precipitation here. The highest temperatures occur in this location in January and February. Winters are coolest in July and August. The climate is temperate. But it is rarely dry because it is located in a zone of prevailing high pressure and descending air. This station is influenced by a nearby warm ocean current. The climate is temperate and seasonal variations are moderated by the nearby ocean. The coastal location also insures that there is sufficient humidity to provide good precipitation throughout the year. The next location has an average temperature about the same as the previous location. But the seasonal variations are much greater. Winters are often bitter cold and the summers tend to be very hot. The precipitation, mostly from thunderstorms and blizzards, is not very plentiful. Warm temperatures and daily rainfall make this climate truly tropical. This location has never had either a frost or a drought. Rising air in this zone of low pressure causes the release of precipitation from the atmosphere. The latitude of this location might lead you to think that it would be hot at this station. But it isn t. Air blowing into this place is cooled by adiabatic expansion as it gains altitude. The climate is constantly cool and comfortable with modest rainfall. There is lots of rainfall here because the winds blowing up the windward side of the mountains quickly cool below the dewpoint. The ocean winds, that provide moisture, also moderate the temperatures. The climate is temperate with comfortable summers and moderately cold winters. Answer the following questions: Increases, Decreases, or Remains the Same 1. As the altitude increases, the temperature usually 2. As you move inland, the yearly temperature variations 3. As the latitude increases, the average yearly temperature 4. As you move inland, the humidity usually

10 Discussion Questions 1. How can you use the calculation of the climate ratio (P/E p ) to determine a climate type? 2. As latitude increases, what general changes occur in climate patterns? 3. As elevation increases, what general changes occur in climate patterns? 4. What effect does a large body of water have on the climate of a nearby landmass? 5. How does a range of mountains affect the climate of a region? 6. How do planetary wind belts affect the climate of a landmass in the mid latitudes? 7. How do the monthly temperatures on a climographs allow you to determine whether an area is in the northern or southern hemisphere? 8. What difference would you expect to find in two climographs representing coastal and inland locations at the same latitude?