Mini Lesson

Chlorophyll & Sea Surface Temperature

Chlorophyll & Sea Surface Temperature

Analyze these satellite images comparing Ocean Chlorophyll Concentrations with Sea Surface Temperatures beginning with the North Atlantic region, then expanding global patterns of these phenomena. Consider using the Map Cube to help students with deeper-dives into data analysis. Credit: NASA Earth Observatory

chlorophyll
Chlorophyll Concentrations (Credit: NASA Earth Observatory)
SST
Sea Surface Temperatures (Credit: NASA Earth Observatory)

 

Mini Lesson

  1. Direct students to analyze the Chlorophyll Concentrations mapped image, paying specific attention to the color bar provided. Ask students what does this mean? [When phytoplankton populations are large, the color of the water appears greener because of high concentrations of chlorophyll.] 
  2. Ask students to brainstorm what living organisms may be observed using chlorophyll data. [phytoplankton]
  3. Recall with students that phytoplankton are microscopic, floating, plant-like organisms that live in oceans, lakes, and rivers. They use photosynthetic pigments (like chlorophyll) to convert energy from the Sun into organic matter. For this reason, NASA satellites can observe the amount of phytoplankton present in the ocean by measuring chlorophyll concentrations.
  4. Direct students to make observations about these data:
    1. Where do you observe the highest concentrations? [higher latitudes and coastal waters] Lowest? [lower latitudes]
    2. What factors do you think control where phytoplankton are distributed?
  5. Now, have students analyze the Sea Surface Temperature mapped image, paying specific attention to the color bar provided. 
    1. Where do you observe the highest concentrations? [higher latitudes and coastal waters] Lowest? [lower latitudes]
    2. What do we call the waters that are found here?  [Gulf Stream, warm current, Labrador Current, cold current, coastal regions are where rivers discharge into the ocean]
  6. Facilitate a discussion with the class about where these concentrations are found:

    • Two mighty ocean currents meet at these crossroads: the Gulf Stream and the Labrador Current. The region is also influenced by variable river discharge in the spring; cold, nutrient-rich waters welling up from the deep in the summer; warm water masses spinning off of the Gulf Stream all year; and intense seasonal stratification, or layering, between warmer and cooler waters.

  7. Now show the following video visualizing Chlorophyll & Sea Surface Temperature from 2002 to 2019.
  8. Students should observe the video and analyze the following:
    1. Where are the highest concentrations of chlorophyll generally located? Do the trends that you observed in the Northern Atlantic also occur in the Southern Hemisphere? [Cold, polar waters in both hemispheres (and places where ocean currents bring cold water to the surface, such as around the equator and along the continents) experience high levels of chlorophyll.]
    2. How do the values of chlorophyll change over the seasons? In the hemisphere experiencing summer, we can see the biggest differences between the equatorial regions and polar regions.
    3. Why do you think that the polar regions experience these changes during the spring/summer seasons?  [Day length increases so phytoplankton flourish with more sunlight.]