The four days shown in enhanced true color below account for most of the anomalous signal in the 2005 composite. The appearance of these blooms and their location in waters that are usually low in reduced or oxidized nitrogen suggests that they could be composed of the nitrogen-fixing cyanobacterium, Trichodesmium. Trichodesmium is likely an important driver of biological productivity in such nutrient-limited tropical waters.
To grow and fix atmospheric nitrogen, Trichodesmium is itself limited by the availability of other nutrients such as iron. If these blooms are indeed Trichodesmium, one wonders where they get their iron from in such a remote location.
Click on the different days for larger views. The circles below are roughly 200 kilometers in diameter.
