MODIS - Terra

MODIS provides the unprecedented ability to measure chlorophyll fluorescence, which gives insight into the health of phytoplankton in the ocean. When phytoplankton are under stress, they no longer photosynthesize and begin to emit absorbed sunlight as fluorescence. This image taken over the Arabian Sea shows a ratio of chlorophyll to fluorescence which provides information on the degree of photosynthetic activity occurring (blue shows higher photosynthesis).

An immense mixture of sediment and phytoplankton, visible as blue-green and brown swirls, clouds the waters off China in this MODIS image captured on November 1, 2001.

This MODIS image shows the wide sediment plume of the Yangtze River as it empties into the East China Sea.

A MODIS view of sediment emerging from the mouth of the Yellow River in China.

Tan-colored sediment spills out into the Yellow Sea from rivers in eastern China. The nutrients in the sediment may be responsible for the bloom of phytoplankton seen as blue and green swirls farther away from shore.

On the western coastline of the Korean Peninsula, the waters of the Yellow Sea are murky with what is likely a mixture of sediment and phytoplankton.

A large amount of sediment is clearly visible in the Persian Gulf. Carried by the confluence of the Tigris and Euphrates Rivers (at center), the sediment-laden waters appear light brown where they enter the northern end of the Persian Gulf and then gradually dissipate into turquoise swirls as they drift southward. The nutrients these sediments carry are helping to support a phytoplankton bloom in the region, which adds some darker green hues in the rich kaleidoscope of colors on the surface (see the high resolution image).

The Palk Strait is filled with bright sediment, while off the northeast tip of Sri Lanka, a dark stain in the waters could be a phytoplankton bloom.