Five Spheres - Biosphere

Satellite data can be used to monitor the health of the biosphere from space. This animation of seasonal changes to the biosphere is match framed to animation entries 3707, 3708, 3710, and 3711. The SeaWiFS instrument is carried aboard the satellite OrbView-2, providing important information about the oceans, the land, and the life within them. On land, the dark greens show where there is abundant vegetation and tans show relatively sparse plant cover. In the oceans, red, yellow, and green pixels show dense phytoplankton blooms, those regions of the ocean that are the most productive over time, while blues and purples show where there is very little of the microscopic marine plants called phytoplankton. For most of the world's oceans, the most important things that influence its color are phytoplankton. Phytoplankton are very small, single-celled plants, generally smaller than the size of a pinhead that contain a green pigment called chlorophyll. All plants (on land and in the ocean) use chlorophyll to capture energy from the sun and through the process known as photosynthesis convert water and carbon dioxide into new plant material and oxygen. Although microscopic, phytoplankton can bloom in such large numbers that they can change the color of the ocean to such a degree that we can measure that change from space. The basic principle behind the remote sensing of ocean color from space is this: the more phytoplankton in the water, the greener it is...the less phytoplankton, the bluer it is. For more information, visit http://oceancolor.gsfc.nasa.gov/SeaWiFS/.