Week 10: Exploring Precipitation Patterns

Getting to Know Combining Data in Google Earth

Earth's unique weather and climate determine where life will flourish or perish. Too much rainfall leads to flooding; too little leads to drought and famine. Such extreme situations often result in devastation and loss of life. Throughout history, humans have strived to understand patterns in weather and climate. By developing an understanding of the patterns of precipitation, scientists are making possible increasingly accurate weather, flood and drought forecasts. In the case of drought, these forecasts allow water managers to decide how to allocate precious water resources. Conversely, in the case of flood events, careful precipitation monitoring and forecasting can improve strategies intended to prevent damage and suffering.

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Create a KML File Using Giovanni and Import it into Google Earth

Flooded street in Wayne, NJ on Tuesday, March 30, 2010. Image Source: AP Photo/Mel Evans.
Many places across the country experienced very wet weather during this year's winter and early spring. Record-setting rainfall in late March caused extensive flooding in the Northeast, from New York to Maine. These floods led to major road closures, evacuations, and property damage.

The NASA-JAXA Tropical Rainfall Measuring Mission (TRMM) provides near-real-time rainfall information around the world. In this section, we'll use the TRMM Online Visualization and Analysis System (TOVAS), one of Giovanni's hydrology instances, to obtain rainfall data for the Northeast during the 2010 flooding and bring it into Google Earth.

  1. Launch the Giovanni TRMM Online Visualization and Analysis System in a new window.
  2. When this page loads, you will see a map of the world. Select your area of interest, the Northeast United States, using the Click and Drag Selection tool.
    HINT: If you're feeling rusty with the Giovanni interface, go back to Week 4: Getting to Know Giovanni for a refresher lesson.

  3. Choose precipitation as the data Parameter.
  4. Set the Temporal parameters: Begin Date: March 29, 2010, Hour 00; End Date: March 31, 2010, Hour 21
  5. Leave the visualization type as Lat-Lon map, Time-averaged and click the Generate Visualization button.
  6. Click on the Download Data tab at the top of the page.
  7. Scroll down to the bottom of the page. Under the Output Files heading, check the box next to the KMZ icon. Then click on the KMZ icon. The file will download to your computer and, depending on your settings, launch Google Earth.
  8. Launch Google Earth by double-clicking its icon on your computer's desktop or by clicking its icon in the Start menu or launch bar (Win) or the dock (Mac).
  9. Click File > Open, navigate to your Week 10 folder, select the KMZ file you downloaded from Giovanni, and click Open. The file will be added to the Temporary Places section of your Places panel.

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Create a Placemark with Images and Links

Last week, you learned how to make a simple placemark in Google Earth. To add interest (and information) to placemarks, you can add links and imagesall you need are the urls and some simple HTML tags. All HTML tags are enclosed by brackets. A particular instruction can be turned off by placing a / within the brackets, before the command. Below you will find all the HTML tags you will need to add images and links to a placemark. The HTML tags are in capital letters and annotations are in italics.

  1. Fly To Littleton, MA.
  2. Click the Add Placemark button ge_add_placemark and a New Placemark window opens.
  3. In the New Placemark window, click the pushpin icon in the upper right corner. This opens an Icon window. Click on the rain cloud icon to choose it. Then click OK.
  4. In the New Placemark window, give the placemark the name Littleton, MA. In the placemark's Description box, type the following and click OK.

  5. Click on the placemark in the 3D Viewer to see your new and improved placemark.

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Use Giovanni to Explore Precipitation in a Region and Time of Interest to You

  1. Choose a precipitation event (i.e., a period of significant rainfall where you live, a major hurricane, etc.) of interest to you.
  2. Find an image that complements the precipitation event. The photo you choose must be hosted online and have a url that ends in .jpg. Here are some good places to look for images (an old fashioned Google search or a visit to your own online photo sharing site like Flickr or Picasa would work too). When you find your image, make sure you write down or copy the urlyou'll need it when you create your placemark.
  3. Follow the same procedures as above to generate a KMZ file in Giovanni and bring it into Google Earth.
  4. Follow the same procedures as above to create a placemark with an image.
  5. Once you have created the placemark and tested it, take a screen shot of the entire Google Earth window and save it. This is the screen shot you will post on your Review & Discussion page this week.
  6. This is the screenshot that is needed for your required weekly activity.

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