Where is the ocean chlorophyll in January?

Chlorophyll levels in the world's oceans in January

In the image above, reds and yellows signify large amounts of chlorophyll in the water, while lower levels are shown as blue and purple. Just like on land, chlorophyll is found in sea plant life. As you can see above, during January there is more red in the southern hemisphere, where it is summer. This means that there are greater amounts of the phytoplankton plant life in these areas. Contrast this with the northern hemisphere, where it is winter. Just like on land, plants in the ocean grow more during the (local) spring and summer. Note how productive the polar oceans are... and that most of the bioactivity in the oceans is found near the coasts. This is why pollution from rivers can cause a major problem - although the oceans are huge, most of the plankton at the bottom of the food chain grow near the shores.

Credit: NASA/GSFC

For more info: http://daac.gsfc.nasa.gov/CAMPAIGN_DOCS/OCDST/OB_Education.html