This week’s guided exercise will use EO data to look at sea ice cover and will enable you to view changes over the annual cycle as well as over a number of years.

For this exercise we will use the World View tool from NASA.

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 locations and 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’, only the ‘Corrected Reflectance (True Colour) Terra/MODIS’ and ‘Corrected Reflectance (True Colour) Aqua/MODIS’ layers are selected.

3. Next you will need to add another layer to the ‘Overlays’ menu. Click on the ‘Add Layers’ plus symbol and then click on ‘All’. Scroll down until you find the layer called ‘Sea Ice’ and select ‘Terra/MODIS Sea Ice’. You can now see that the layer that have now been added to ‘Overlays’.

4. On the time slider at the bottom of the screen, select 1st January 2013. You should now be able to see the Sea Ice data displayed for this date.

5. Take a snapshot of a region of this data set using the camera symbol in the top right-hand corner. 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 to ‘5 km’ to keep the file size (shown under ‘Raw Size’) down to a manageable level. Click Download. The image will appear in a new tab. (You can then save this image to your desktop or pictures folder).

6. Now move the time slider to 1st July 2013. You should now be able to see the data displayed for this date. Take another snapshot of this data set. Now use both of your images to compare summer and winter sea ice concentration in 2013.

7. Now repeat this comparison for 1st January 2016 and 1st July 2016, taking a snapshot of both data sets. Compare the seasonal changes and see if you can see any change over time from 2013 to 2016.