PART I: Collecting data from National Earth Observatory

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Elfreda Oliver
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1 Investigation: Sea Surface Temperature We ve seen how temperature varies with depth, but how does it vary with latitude and season? In this investigation, you are going to explore sea surface temperatures for an entire calendar year. We will be using three tools, the National Earth Observatory (NEO) Database, ImageJ, and Google Earth to aide in our studies. PART I: Collecting data from National Earth Observatory 1. Launch the following website: 2. Cick on the Oceans tab under the blue marble image of the Earth. 3. Choose one of the following Datasets: Sea Surface Temperature (AMSR-E) or Sea Surface Temperature (MODIS). These datasets both contain data from different satellites. The data in both of these datasets goes back to Pick a year, and then choose a month to View. In the end you will have one twelve month time period. 5. Create a folder for you lab group in our share folder called SSTyear (example: SST2010) then download the image to your share folder on the T drive. You will want to rename the file ##MonthYear.jpg (example: 03March10.jpg) 6. Repeat for eleven other months. 7. What color represents the warmest temperatures? What color represents the coldest temperatures? 8. Once you have these four images, launch ImageJ.

PART II: Introduction to ImageJ ImageJ can display two or more images in a single window, as a stack. The images or layers that make up a stack are called slices.

To stack a set of images, they must all be the same width, height, and bit depth. The number and size of the images you can stack depend on the amount of memory in your computer.

2 PART II: Introduction to ImageJ ImageJ can display two or more images in a single window, as a stack. The images or layers that make up a stack are called slices. Stack windows have a scroll bar across the bottom to cycle through the slices, and you can animate the images at speeds from one frame every 10 seconds to over 1000 frames per second. To stack a set of images, they must all be the same width, height, and bit depth. The number and size of the images you can stack depend on the amount of memory in your computer. What are stacks used for? Stacks are used to display and analyze images that relate to each other in some way, such as by time (temporal), space (spatial), or color (spectral). Stacking temporal images allows you to animate them to rapidly display them in sequence making changes over time easier to see and understand, and allowing you to precisely measure the same regions of the image over time. Creating a Time-Series Stack with ImageJ 1. Choose File > Import > Image Sequence and navigate to the SSTyear folder where you stored the monthly images. 2. Select the first image in the sequence and then click the Open button.

The individual images in a stack are called slices in ImageJ.

3 3. Specify the Sequence Options. Use all twelve slices, beginning with the first slice and incrementing by one. Do not scale the images. Check the Sort Names Numerically option and click OK 4. All twelve images will be imported into a stack named SSTyear. The individual images in a stack are called slices in ImageJ. The window s status bar shows the number of the current slice and total slices (in this case 1/12 or 1 of 12), the width and height of the image in pixels, and the memory occupied by the stack, in this case 12 MB. 5. Choose File > Save to save the stack as SSTyear.tif The SST images are now assembled into a stack.

4 Animate the Stack You can step through a stack one slice at a time, or you can animate it like a repeating movie look. ImageJ lets you control the speed to the animation, so you can show it at a speed that is best suited for viewing. 1. Click and drag the scroll bar at the bottom of the stack widow to move forward and backward through the stack. As you scroll through the stack, notice the changing slice counter and image label at the top of the stack window. Slice 1 is labeled 1/12, slice 2 2/12, and so on. 2. You can also use Next Slice (>) and Previous Slice (<) keyboard shortcuts to move forward and backward through the stack. Try each method of scrolling before moving on. 3. Choose Image > Stacks > Start Animation to animate the stack.

Experiment with changing the speed of the animation, carefully observing the Sea Surface Temperature changes that occur during the year.

5 4. The animation is probably going too fast to see what s going on. To slow it down, choose Image > Stacks > Animation Options 5. Set the Speed to 5 frames per second, and click OK. 6. Experiment with changing the speed of the animation, carefully observing the Sea Surface Temperature changes that occur during the year. What do you observe happen to the temperature of the surface water as the seasons change? Which seasons have the warmest sea surface temperatures off the coast of New Jersey? Does this make sense to you? Record your observations.

The solution is to create a montage rows and columns of thumbnail images on a single page to save and import into your report. 1.

6 7. When you are satisfied with your animation, go File > Save to save the images as SSTyear.gif in your share folder. Create a Montage from a Stack Stacks are great on your computer screen, but how do you represent the image series in a printed report? The solution is to create a montage rows and columns of thumbnail images on a single page to save and import into your report. 1. Choose Image > Stacks > Make Montage 2. Experiment with the various options in the Make Montage window to discover how each option affects the montage image. Make sure you scale to at least 0.50 and label the slices.

3. Here is what the montage should look like. 4. When you have a montage you are satisfied with, go File > Save to save the Montage as SSTyearMontage.tif in your share folder.

7 3. Here is what the montage should look like. 4. When you have a montage you are satisfied with, go File > Save to save the Montage as SSTyearMontage.tif in your share folder. PART III: Analyzing the results using Google Earth 1. Once you have recorded some observations, you are ready to try seeing these images in three dimensions. Return to one of the months in NEO and click on the Open in Google Earth link. 2. This will download a file with a.kmz at the end. When this file has been downloaded, double click on it, and look at what happens to the traditional globe in Google Earth. 3. Repeat this process for three other months, one for each season. 4. Record your observations. Are they consistent with the data in your stack? 5. Which seasons have the warmest sea surface temperatures off the coast of New Jersey? Which seasons have the coolest temperatures? Does this make sense? Explain.

PART I: Collecting data from National Earth Observations

PART I: Collecting data from National Earth Observations Investigation: Air Pollution In this investigation, you are going to explore air pollution around the world for an entire calendar year. We will be using three tools, the National Earth Observations (NEO)