Ocean Biology

Basic idea used by satellites

When sunlight hits the ocean, some of the light is reflected back directly, but most of it penetrates the ocean surface and interacts with the water molecules that it encounters.

Almost all sunlight that enters the ocean is absorbed, including red, orange, yellow, and green wavelengths. The remaining light (blue and violet) is what we see.

Any particles suspended in the water will increase the scattering of the incoming sunlight. In coastal regions, sand and silt suspended in the water absorb blue light and scatter more red and green giving the water a brown colour.

Microscopic marine algae, phytoplankton, absorb blue and red light because they possess specific pigments such as chlorophyll and scatter green light. Consequently, increasing amounts of phytoplankton makes the water appear greener.

Satellite collect data across the globe, allowing us to observe the waxing and waning of algal blooms.

Movie of ocean color

Here is a link to a couple of movies derived from data collected by the NASA MODIS instrument. What they show is the seasonal cycle of ocean color over the entire globe.

Teaching materials

This document is a teacher guidance pack for ocean color. It includes:

• Work outline and how individual topics fit into the GSCE Physics AQA
• Teaching topics that link with a range of activities, including Jupyter notebooks (below)
• Guidance on delivering material and a learning pack, including necessary equipment
• Useful links for further development.

A zip file that contain Jupyter notebooks [166 MB] that support teaching of ocean color .

Please consult the accompanying README file.