This week’s guided exercise will introduce you to the World View tool from NASA, which enables you to freely explore data in a wide range of areas. We will use three types of data relating to this week’s topics to explore seasonal changes around the world.

Follow the steps below and then join the discussion to compare results and discuss ideas with other learners. Once you feel confident with the tool you can explore other data sets of your choice.

You may find it helpful to open the exercise in a separate window.

1. Go to the World View tool. (When you first visit World View you will be offered a tour of its features. You can take this tour if you wish to, but it is not necessary for this exercise).

2. On the left hand side of the screen, make sure that under ‘Base Layers’, the ‘Corrected Reflectance (True Colour) Terra/MODIS’ and ‘Corrected Reflectance (True Colour) Aqua/MODIS’ layers are selected. Under ‘Overlays’, make sure that one of the Coastline layers is selected. (You can hide or show a layer by clicking on the eye symbol next to its name, or remove it completely by clicking on the X).

3. Now click on the ‘Add Layers’ button. A pop-up menu box will appear. Under the Air Quality menu, click on ‘Aerosol Optical Depth’. On the next menu that appears, click the first square next to ‘Aerosol Optical Depth’. You can read more about this data in the text box below the list, entitled ‘MODIS (Terra/Aqua) Aerosol Optical Depth’. Once you have done this, close the pop-up box by clicking the X in the top right corner.

4. On the time slider at the bottom of the screen, select 1st January 2017. You should now be able to see the Aerosol layer displayed on the map for this date. Now select other evenly spaced dates in the same year (e.g. 1st April, 1st June and 1st September). Try to identify whether you can see any patterns of change in any parts of the world over the course of the year. You can also compare with other years.

5. You can take a snapshot of any region of the map using the camera symbol in the top right-hand corner. This could be useful to compare data on different dates, but is not essential. To do this, click on the camera icon and an area selection tool will appear on the map. Adjust the area and change the resolution in the drop down menu (selecting ‘5 km’ or ‘10km’ will help to keep the file size down (shown under ‘Raw Size’). Click Download. The image will appear in a new tab. (You can then save this image to your desktop or pictures folder).

6. Now repeat the steps above for two other types of data, which are both available under the ‘All’ menu in the pop-up menu box: 1) ‘Ozone’ ; 2) ‘Chlorophyll a’. (You can hide the previous layers for a clearer view of the new data layer, or even the base layers too at any time if you prefer).

Once you’ve tried out this exercise, share your thoughts and findings in the discussion below and read the findings of others. Were you surprised by any of the seasonal variations you did or didn’t see?

Take the end of week test

You can take the end of week test by clicking on the test button located on the top-right.