NASA has collected the first continuous global observations of the biological engine that drives life on Earth. Researchers expect this new detailed record of the countless forms of plant life that cover land and oceans may reveal as much about how our living planet functions today as fossil and geologic records reveal about Earth's past.
"This is a period of exploration for us," said lead author Michael Behrenfeld, an oceanographer at NASA's Goddard Space Flight Center, Greenbelt, MD. "We've never been able to see the Earth this way before."
The study, which appears this week in the journal Science, is based on the first three years of daily observations of ocean algae and land plants from the Sea-viewing Wide Field-of-View Sensor (SeaWiFS) mission, creating the most comprehensive global biological record ever assembled. Scientists will use the new record of the Earth's surface to study the fate of carbon in the atmosphere, the length of terrestrial growing seasons and the vitality of the ocean's food web.
"With this record we have more biological data today than has been collected by all previous field surveys and ship cruises," added Gene Carl Feldman, SeaWiFS project manager at Goddard. "It would take a ship steaming at 6 knots over 4,000 years to provide the same coverage as a single global SeaWiFS image."
The new study presents a global assessment of the fundamental work that plants perform to make life possible producing food, fiber, and oxygen and how their productivity changes from season to season and year to year in response to our changing environment.
The biological record from SeaWiFS indicates that global plant photosynthesis increased between September 1997 and August 2000. Photosynthesis by land plants and algae absorbs carbon dioxide from the atmosphere and ocean, which plays a critical role in regulating atmospheric carbon levels. The initial increase in carbon fixation was largely due to the response of marine plants to
Contact: Cynthia M. O'Carroll
NASA/Goddard Space Flight Center