Mini Lesson

Tracking Monthly Salinity Changes in Our Ocean

Mini Lesson

Create a time-series graph to explore the salinity values of our ocean changes over time and depth.

  1. Visit the Historical Changes in Monthly Mean Data tool to access salinity time series for the two pre-selected profiles in the polar regions.  Blue for the Arctic, Red for the Antarctic.
  2. Review the color bar. 
    • Answer the following questions: What color and value is represented by high salinity values? low?
  3. Locate the blue and red dots showing key locations for map and time-series plots in the image below.

4. Click on the "Plot" button beneath the "Selected Location List" to see the time series. Display the graph.

polar monthly changes
Salinity Changes in the polar regions.  Credit: NASA Aquarius

5. Observe the salinity values for the polar regions and answer the following questions. 

  1. What changes do you observe and when do these changes occur?  
  2. Analyze to see if a relationship exists between these variables and explain your findings.
  3. What may explain this pattern? 

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