Water Cycle - Weather (4)
Post Lab 

   
OBJECTIVES:
  • Analyzing the average weather over a period of time.
  • Discovering weather and climate patterns using the Internet.
VOCABULARY:
  • snow
  • rain
  • mild climate
  • cold climate
  • warm climate
MATERIALS:

Students look for weather patterns to determine climate.

BACKGROUND:

Climate can be considered the average weather conditions over a long period of time. The climate is influenced by latitude, land and water distribution, altitude, land barrier, air movement, ocean currents, permanent storm areas, temperature, humidity, precipitation, cloud cover, high and low pressure centers, and other weather phenomena.

Overall the major control is governed by solar radiation. This was first recognized by Eratosthenes (276-192BC) who observed that the angle of the Sun’s rays had something to do with solar radiation. This in effect is due to the tilt of the Earth on its axis, which throughout the year causes the change of the seasons. However, do not confuse seasons with climate. climate has many other factors that have to be considered. For instance the climate in St. Louis, Missouri, Washington, D.C. and San Francisco, California are very different, but yet they receive the same solar radiation. Mountains, closeness to coastal area, and other parameters can cause very different climate.

Climates can be defined by temperature, rain, and humidity. We recognize the following: Tropical climates (rainforest, savanna and monsoon); dry climates (desert and grasslands); mid-latitude climate (humid subtropical, marine west coast, Mediterranean, and mid latitude monsoon); and polar including tundra areas which are frozen all year round.

PROCEDURE:
  1. The internet has a wealth of information for students to use to develop their own idea of climate. In this exercise the web sites provide long term information on temperature and precipitation. On the web site we highly suggest you access data from any year. There is many ways to have the students interpret this data.
      
    http://www.cdc.noaa.gov/USclimate/USclimdivs.html/
  1. Students could compare the temperature and/or precipitation the year they were born and last year.
      
  2. Students could look at every 10 years of temperature and see if the United States is actually "cooling" or "warming." Debate is sure to occur.
      
  3. Students can look at five years in a row, and see if they could predict the 6th year with that information.
  1. If you do not have internet access we suggest that you use the figures included in this lesson and have the students look at all the states to determine whether it has gotten cooler or warmer. Use a map of the United States to make sure that students know their states. You may want them record the information on a blank map or just to just to gather the data in a data chart.
      
  2. The worksheet has the students look at temperature in the United States in January, 1990 and January, 1996. You cannot make a "scientific conclusion" from only two data points. To interpret data you must have sufficient data to make a valid interpretation that is accurate. New data can sometimes change the interpretation.

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