Mini Lesson

Historical Ocean Salinity Data: Annual Mean Data

Mini Lesson

Ocean Salinity:

1.  Open this link to show the interactive map of surface salinity used to create in-water profiles of how the salinity changes with depth (NOTE: Profiles of temperature and density may also be created using this tool). 

  • How do we know that map shows only surface conditions?  

mapped locations
Credit: NASA Aquarius Annual Mean Salinity Map

2. Observe the color bar. What colors represent the high salinity values? 

    3. Locate the blue, green, and red dots in the image above showing key locations for maps and in-water salinity profiles.  What colors are represented by the coordinates below?

    • 5N, 24W
    • 18S, 20W 
    • 62S, 34W 

    4. Click the "Plot" button, located below the "Selected Location List" box. In-water profiles from these locations will appear at right. 

    Aquarius; In-Water Profiles for Salinity
    Credit: Aquarius; In-Water Profiles for Salinity

    5. Review the features of the graph above or their graphs. 

    6. How does salinity vary with depth? Describe by using evidence for the three sites.

    Teacher Note

    Teachers who are interested in receiving the answer key, please contact MND from your school email address at