EarthLabs > Earth System Science > Lab 3: Discovering Local Data > 3B: Graphing GLOBE Data

Lab 3: Discovering Local Data

Part B: Graphing GLOBE Data

Step 1. Filter the Data to Select Reynolds Jr Sr High School

As you saw in Part 1, many schools contribute to the GLOBE database, making it a powerful Earth Science tool. In this lesson, you are going to use the data from one school, Reynolds Jr. Sr. High School in Greenville PA.
  1. In the Filters panel, located on the right side of the screen, change the Map Date to January 1, 1998. (1998-01-01)
  2. Then click the Location / Site toggle and select the school and site.
    • Select by: Schools
      School Name: Reynolds Jr Sr High School (Hint: type in the first word and use the list to find the school)
    • Sites: Weather Station ATM-02
      Note: there are several sites listed here, choose the Weather Station ATM-02.
  3. A new pop-up window will appear on the map, set the Obtain Data pull down menu to Time Series Plot and choose the Maximum Daily Temperature from the list of choices. Then click the Plot data icon located to the right of the choices.
    Hint: it looks like a mini graph plot data icon
  4. In the image below, the settings for data from Reynolds Jr Sr High School have been selected.

Step 2. Select the Date Range

Now that you have selected the school, site, and protocol, you will use the filter to set the date range.
  1. Under the Selected Data Graphs & Tables, set the plot date range to the following: 1996-01-01 to 2003-01-01
  2. Check the Use Auto Y-axis checkbox.
  3. Then click the Plot All button.
  4. You will receive a message about the size of the data set; ignore it and click OK to continue.
  5. The settings have been set for the 5-year graph in the image below.


    The error message is displayed below. Ignore it and click OK to continue.
    When you choose Time Series Plot and click the Plot All button, you launch the GLOBE Graphing Tool. The default graph always shows the Maximum Air Temperature data for the entire period of time that a school has been participating in the GLOBE program, but as you'll see later, there are many options for customizing your view of any data that the school has collected. In this case, you are looking at the daily maximum temperature reading at Reynolds Jr. Sr. High School across an eleven-year time period. Focus on the years where the data collection was most frequent and consistent: 19962003.


    Checking In

    • The Maximum Air Temperature is showing somewhat of a repeating pattern here. What do you think the reason for this is?
    • Is the pattern similar to one you might expect to see for maximum air temperature in your own city or town? If not, what are the differences?


Step 3. Change the Time Frame of the Graph to Two Years

  1. Under the Selected Data Graphs & Tables Filter, set the plot date range to the following:
    1998-01-01 to 1999-12-31
  2. Check the Auto Y-axis checkbox and then, click the Plot All button to plot two years of temperature data.
    You now have just two years of maximum temperatures on the screen—all of 1998 and 1999—and you may see that each day is represented by a small dot.
  3. Look carefully at the two-year graph. Then answer the Checking In questions.




    Checking In

    • Look at the temperature scale, which runs along each edge of the graph. On approximately what date does the highest maximum daily temperature occur in 1998? When does it occur in 1999?
    • Compare the two years and describe the differences and similarities you see.

Step 4. Add Data for Soil Moisture (10 cm) to the Graph

Repeat steps 1-3, above, to add soil moisture data to your map and to the Selected Data Graphs & Tables list.

  1. First, select the school, then the soil moisture (SMS) site.
    In the Filters list, select the following:
    School Name: Reynolds Jr Sr High
    School Sites: School Location: SMS-01
    Note: there are several sites listed here, you must use the pull-down menu and switch the filter to choose the Soil Moisture site (SMS-01).
    Keep the date range the same as the temperature data. (1998-01-01 to 1999-12-31)
  2. Next, in the Layers list, click the Add + data link. Choose the Soil > Soil Moisture (Sensors) from the Protocol drop-down menu. Select the 10 cm soil Sensors Moisture radio button and then click the Plot data button. You should now see a second data layer in the list of data to graph as well as a new icon and legend on the map.

    You should now have two data sets that appear in the graph. Soil moisture content is defined in terms of weight. It is a measure of the weight of water that exists in a gram of soil. Notice that the scale along the right side of the graph has changed. The unit of measurement for soil moisture is gram/gram, or g/g.

  3. Look carefully at the graph of Maximum Temperature and Soil Moisture (10 cm). Then answer the Checking In and Stop and Think questions.

    Checking In

    • During which months does soil moisture at 10 cm remain basically steady?
    • During which months does soil moisture at 10 cm change quite frequently?
    • What change do you notice as you compare soil moisture for 1998 with 1999?


    Stop and Think

    1: Do air temperature and soil moisture at 10 cm follow the same pattern? Why or why not?
    2: What does this graph show about the interconnection between air temperature and soil moisture at 10 cm?


Step 5. Add Data for Soil Moisture (90 cm) to the Graph

  1. In the Selected Data Graphs & Tables list, you should now see two data sets:
    • SMS-01 Soil Moisture Sensors 10 cm Depth
    • Weather Station ATM-02- Air Temperature Dailies
  2. Repeat the steps from above to add a second soil moisture dataset to your graph.
    1. Be sure that you have chosen the soil moisture site (SMS) from the list of school sites given in the Filters list.
    2. Choose the Soil Moisture (sensors) from the drop-down menu.
    3. Select the 90 cm soil moisture sensors radio button, and then click the Plot data icon.
  3. In the Filters list, under Selected Data Graphs & Tables, you should now see three data sets in the list.
  4. Click the Plot All button again. A new graph will be generated with all three data sets.

  5. Look carefully at the new graph. Then answer the Checking In questions.




    Checking In

    • In what ways is the graph of Soil Moisture (90 cm) similar to the graph of Soil Moisture (10 cm)?
    • In what ways are the two Soil Moisture graphs different?
    • How does the 1998 graph compare with the 1999 graph for soil moisture at each depth?

Step 6. Add Data for Rainfall to the Graph

  1. Return to the Filters panel and select the following:
    • School Name: Reynolds Jr Sr High School
    • Sites: Weather Station ATM-02
  2. In the pop-up window, under protocols, select Atmosphere > Precipitation > Rain Depth from the protocols drop-down menu, and then click the Plot data icon. In the Filters list, under Selected Data Graphs & Tables, you should now see four data sets in the list.

  3. Keeping the date range set to the same 2-year period, click the Plot All button. A Time Series plot of all four variables will be generated.
  4. Notice that a new scale has been added to the right of the graph, and that the unit of measurement is mm for millimeters of rain. There is now a lot of data crowded into a small space. In Lab C, you will be getting a closer look at the details. However, you should be able to see enough detail to answer this one last question about the data.



    Checking In

    • Look at the rainfall data for both years. Do you think that Greenville, PA has a rainy season?
    • Is there a rainy season where you live?

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