Lab 6: A Year in the Life of the Earth System
Part A: The Earth System in 2017
In this part of the investigation, you will work in small groups to examine 12 monthly images of the variable/dataset you explored in Lab 5, looking for any changes that occur over the course of the most recent year. NOTE:
If you are unable to download the most current data from NEO, scroll to the bottom of the page for alternate instructions, using example files for the year 2017.
- Create a new folder on your computer to hold the images you will download. Name your folder to match the dataset you will download (Insolation, Aerosols, SST, Land Temp, or Vegetation).
- Go to the NASA Earth Observations (NEO) website. The NEO Website will open in a new browser window.
- Select and display a monthly map for January of the last full year (e.g., if it is November 2018, you should select and display a map for January 2017) for your group's assigned dataset:
- Energy Group: Solar Insolation
- Atmosphere Group: Aerosol Optical Thickness
- Ocean Group: Sea Surface Temperature (SST)
- Land Group: Land Surface Temperature [Day]
- Life Group: Vegetation Index
- Create a new folder on your computer to hold the 12 images you will download. Give the folder a name that describes the images you will download (e.g., Solar Insolation 2017 or Sea Surface Temperature 2018).
- You should still have the January image for your group displayed in NEO. Download this image at a resolution of 0.5 degrees.
- Click on February above the slider to view the image for February. Use the same procedure as above to resize and generate an image with a fixed resolution of 0.5 degrees. Save the image as 02_name.jpg.
- Repeat this process for March through December so that you end up with a total of 12 images named from 01_name.jpg to 12_name.jpg.
- If your computer does not already have ImageJ, a free image processing software program developed at the National Institutes of Health, download and install it now.
- Go to the ImageJ Download page, and download and install the application for your operating system
- For more details, or if you have problems running the application, access ImageJ's Installation Instructions then select your operating system.
- NOTE: Instructions for this activity were written using ImageJ version 1.52c. Commands may vary slightly for different versions of the software.
- Launch ImageJ by double clicking on the application icon
or by selecting it from the Start menu.
- Choose File > Import > Image Sequence... and navigate to the folder where you stored your 12 monthly images.
- Select the folder containing the images and then click the Choose button. Specify the Sequence Options. Use all 12 images, beginning with image 1 and incrementing by one. Do not scale the images. Check Sort Names Numerically and click OK.
- All 12 images will be imported into a stack with the same name as the folder you stored them in. The individual images in a stack are called "slices" in ImageJ. The image below shows the first of the twelve total slices (1/12). The width and height of the stack in pixels, and the size of the stack, in this case 12 MB, are displayed at the top of the window just below the name of the stack.
- Choose File > Save As > Tiff... to save the stack as Folder_Name.tif. (Folder_name will be replaced with the actual name of your folder.)
- Choose Image > Stacks > Animation > Animation Options... to set the speed of the animation to one frame per second and animate your image stack.
- Use Image > Stacks > Animation > Start Animation and Image > Stacks > Animation > Stop Animation to start and stop the animation. You can also use the play/pause button at the bottom left of the stack window or use the slider bar at the bottom of the image to step through slices one at a time.
- Watch the animation several times through, looking for changes over time. Click on your group name below to view the scale bar for your image sequence.
- With your group, identify annual cycles for your variable by answering the following Stop and Think questions. Hint: if you are having trouble locating significant changes, try focusing your attention on one location on the image throughout the year.
Stop and Think
1: What changes do you see through the year? What explanations can you suggest for these patterns?
2: Choose a location or region. During which months do the extreme highs and lows occur? What explanations can you suggest for the timing of those extremes?
3: Which regions experience both the extreme highs and lows? Which regions don't experience the extremes? Why do you think this happens?
4: What differences, if any, do you find between the year's variations over the oceans versus the year's variations over the continents?
5: Are there regions that remain relatively unchanged over the year? Why do you think this happens?
- Designate a spokesperson to report your group's observations.
- Share your discoveries of patterns and your interpretation of those patterns with the rest of the class.