Weather and Climate 1-2 KEY CONCEPTS AND PROCESS SKILLS KEY VOCABULARY ACTIVITY OVERVIEW P R O B L E M S O LVI N G E-37

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1 Weather and Climate to minute sessions ACTIVITY OVERVIEW P R O B L E M S O LVI N G Students use a literacy strategy known as a DART (directed activity related to text) to organize the information about different climates (dry, tropical, etc.). They identify their local climate and compare their personal observations and seasonal weather averages to the climate description. Students then examine climate graphs for three different regions and use the graphs to identify each region s climate. The class discusses the relationship between climate and weather. KEY CONCEPTS AND PROCESS SKILLS (with correlation to NSE 5 8 Content Standards) 1. Weather is the outdoor conditions (such as temperature, precipitation, wind, etc.) at a particular time and place. (EarthSci: 2) 2. Climate is the average weather for a place over a long period of time (usually at least 30 years). (EarthSci: 2) 3. Graphs can reveal patterns that are not immediately apparent from data tables. (Inquiry: 1) 4. Meteorologists, atmospheric scientists, climatologists, and hydrologists study different aspects of earth s weather and atmosphere. Society relies on the information provided by such scientists. (History: 1) KEY VOCABULARY climate climatologist latitude weather E-37

2 Activity 53 Weather and Climate MATERIALS AND ADVANCE PREPARATION For the teacher 1 Transparency 53.1, Sample Climate Graph * 1 overhead projector For each student 1 Student Sheet 53.1, Directed Reading Table: Weather and Climate * data from Table 3 of Activity 51, Monthly Weather Averages *Not supplied in kit TEACHING SUMMARY Getting Started 1. Students use images to compare the concepts of weather and climate. 2. Review how to read a climate graph, using Transparency Doing the Activity 3. (LITERACY) Students identify and describe climate. 4. (MATHEMATICS) Students analyze graphs and identify the climates of three different places. Follow-Up 5. Students summarize the relationship between weather and climate. EXTENSION Students construct a climograph for their local area using data from Activity 51.if this E-38

3 Weather and Climate Activity 53 BACKGROUND INFORMATION Weather and Climate Weather is the condition of the atmosphere at a particular time and place. It is described and measured by such factors as temperature, precipitation, and wind speed. In most places, the weather can change quickly from one set of conditions to another. Climate is the long-term (usually at least 30 years) weather average for a particular area. Like weather, it is described by temperature, precipitation, humidity, wind and other conditions. The climate of the Arctic, for example, could be described as cold with little precipitation; the summer climate in Florida is very humid; and the northeastern United States often has heavy winter snowstorms. Just as a rainy day can include short periods of sunshine, a region may experience weather that does not reflect its long-term average. For example, an area with a rainy climate may experience a drought lasting several years; winter temperatures may be unusually high for higher latitudes; or a desert may receive lots of rain for a short period of time. Such changes do not mean that there has been a change in the climate for that region. A change in climate requires a long-term change in the average weather. A region can experience several years of unusual weather and then return to its average weather. Climate Classification There are several different systems for classifying climates. One of the more commonly used is the Koppen system, named after its original creator, Wladimir Koppen ( ). Since he developed his system in 1900, it has been modified several times and now includes six major climate categories based on average annual and monthly temperatures and precipitation. Each of these categories tropical, dry, mild, severe, polar, and highland is identified, respectively, by a capital letter from A to E and H. These categories are further subdivided and may be identified by variations in precipitation (with lowercase letters used to identify one of four precipitation variations) and temperature (with additional lowercase letters used to identify one of six temperature variations). According to this system, much of the southeastern United States, for example, is categorized as Cfa : C representing a mild, mid-latitude climate; f indicating that the climate is constantly moist, with rainfall throughout the year; and a indicating that the warmest month is above or equal to 22 C. REFERENCES National Drought Mitigation Center. What is Drought? Climographs of Selected U.S. Cities. Lincoln, Nebraska: University of Nebraska, Retrieved August 2005 from E-39

4 Activity 53 Weather and Climate TEACHING SUGGESTIONS GETTING STARTED 1. Students use images to compare the concepts of weather and climate. Have students turn to Activity 53, Weather and Climate, in the Student Book. Tell them that in this activity they will consider the difference between weather and climate, which are both described in the introductory text. Have students read the introduction. Then tell students to turn back to page E-4 of Activity 50 and look at the four images of weather. Ask them, How would you describe the weather in each picture? Possible descriptions include raining, sunny, windy, and snowing. Ask students to focus on one of the images and imagine what the weather in that image might be like the following day, week, or month. Ask them to consider how the weather might change over the course of many years and how they might describe the average weather that they are imagining. Explain that climate describes the average weather for a region for a long period of time (usually at least 30 years). In the case of a rainforest, the climate could be described as wet or moist, because of high levels of precipitation. 2. Review how to read a climate graph using Transparency During the activity, students compare climate descriptions to climate graphs. The climate graphs show both average monthly temperature (line graph) and precipitation (bar graph) on a single graph. Use Transparency 53.1, Sample Climate Graph, to review how to read both temperature and precipitation on a single graph, making sure to identify the relevant axis and its units of measurement. Note that the two graphs on Transparency 53.1 are identical, but one shows the data in metric units while the other shows it in English units. DOING THE ACTIVITY 3. (LITERACY) Students identify and describe climate. Directed Activities Related to Text (DART) is a literacy strategy that helps students process written information. Student Sheet 53.1, Directed Reading Table: Climate, is a DART that guides students to identify and summarize important points from the text. Hand out Student Sheet A sample response is shown below. Sample Response to Student Sheet 53.1, Directed Reading Table: Climate Climate Type Summer Temperatures Winter Temperatures Precipitation Other Information Polar < 10 C Mostly below freezing (0 C) Very little; usually falls as snow Long cold winters Severe > 10 C At least one month < -3 C Varies Mild > 10 C Between 18 C and -3 C Moist; more rain in winter or summer Highland Between -18 C and 10 C Between -18 C and 10 C Varies; usually falls as snow Very high mountains Dry Hot days, cool nights; can be > 31 C Hot days, cool nights Very little Tropical Above 18 C Above 18 C More than 150 cm rain in a year Hot year-round E-40

5 Weather and Climate Activity 53 In Procedure Step 3, students work in pairs to identify their local climate from information on the map in the Student Book. They record similarities and differences between their experiences and the description of the local climate type. They then compare the description of the climate type with their data from Activity 51, Investigating Local Weather. Assist students as needed. 4. (MATHEMATICS) Students analyze graphs and identify the climates of three different places. For Procedure Step 4, use Transparency 53.1, Sample Climate Graph, (based on data from Eugene, OR) as a model of how to identify the climate of an area. Students might begin by comparing the pattern of precipitation to that of the climate descriptions. Once they see that the sample graph appears to match the description of a mild climate, they can evaluate if the temperature criteria for this climate match the sample graph (they do). They can conclude that the sample graph represents one type of mild climate. each place; the goal is for them to determine the climate based on the data and not prior knowledge of a region s climate. FOLLOW-UP 5. Students summarize the relationship between weather and climate. You may wish to go back and discuss the climate type for your region. Ask students, In what ways did the climate description reflect your local seasonal weather data and your personal experiences? In what ways did it differ? What does this tell you about categorizing climates? Encourage students to describe and identify similarities and differences between the description and their data. Summarize these concepts as a class. EXTENSION Students construct a climograph for their local area using data from Activity 51. Answers to the climate types are shown below. Note that students are not given the actual location of Sample Response to Procedure Step 4 Climate Graph for Place Climate Reasoning Graph based on data from A Tropical Graph shows more than 150 cm rain in a year and temperatures above 18 C year-round Hilo, HI B Dry Very little precipitation; maximum temperature above 31 C Phoenix, AZ C Severe Precipitation varies; summer temperatures above 10 C; winter temperatures below 3 C Minneapolis - St. Paul, MN E-41

6 Activity 53 Weather and Climate SUGGESTED ANSWERS TO QUESTIONS 1. What are the most common climate types in the United States? Dry, mild, and severe. 2. Compare your responses to Student Sheet 53.1 to Figure 1, Map of Climates of North America. How do temperatures vary with latitude? Support your answer with evidence from this activity. Temperatures are colder in the northern latitudes and tend to become warmer approaching the equator. The northernmost areas of North America have a polar climate, which has temperatures below 0 C for 8 10 months of the year. The southernmost areas of North America have a tropical climate, with average temperatures above 18 C. 3. What is the relationship between weather and climate? Weather and climate both refer to outdoor conditions such as temperature and precipitation. Weather describes these conditions day to day, while climate describes them on average and over a much longer period of time. 4. Could areas with different climates have the same weather? Explain. Yes. Climates describe average long-term conditions, while weather describes daily conditions. It is possible for places in different climates to have similar weather. For example, both severe and mild climates have summer temperatures above 10 C. Mild climates are moist, while the amount of precipitation in a severe climate varies. There may be many days when both climates experience identical temperatures and precipitation. In addition, a particular climate can have a day of unusual weather. For example, a place in a dry climate might experience a thunderstorm that produces a lot of rain. Since climate is based on long-term averages, such weather would not affect the climate type. E-42

7 Sample Climate Graph Precipitation (cm) Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec -12 Month Temperature ( C) 2006 The Regents of the University of California Precipitation (in) Jan Feb Mar Apr May Temperature Precipitation Jun Jul Aug Sep Oct Nov Dec 10 Month Temperature ( F) Issues and Earth Science Transparency 53.1 E-43

8 Name Date Directed Reading Table: Weather and Climate Climate Type Summer Temperatures Winter Temperatures Precipitation Other Information 2006 The Regents of the University of California Issues and Earth Science Student Sheet 53.1 E-45