Decadal Comparison of Plankton Levels

The global ocean chlorophyll archive produced by the CZCS was revised using compatible algorithms with SeaWiFS. Both archives were then blended with in situ data to reduce residual errors. This methodology permitted a quantitative comparison of decadal changes in global ocean chlorophyll from the CZCS (1979 - 1986) and SeaWiFS (1997 - 2000) records. Global spatial distributions and seasonal variablility of ocean chlorophyll were similar, but global means decreased over the two observational segments. Major changes were observed regionally: chlorophyll concentrations decreased in the northern high latitudes while chlorophyll in the low latitudes increased. Mid-ocean gyres exhibited limited changes. The overall spatial and seasonal similarity of the two data records suggests that the changes are due to natural variability. These results provide evidence of how the Earth's climate may be changing and how ocean biota respond.

Visualization Credits

Joycelyn Thomson (NASA/GSFC): Lead Animator
Watson Gregg (NASA/GSFC): Scientist
Please give credit for this item to:
NASA/Goddard Space Flight Center, The SeaWiFS Project and GeoEye, Scientific Visualization Studio. NOTE: All SeaWiFS images and data presented on this web site are for research and educational use only. All commercial use of SeaWiFS data must be coordinated with GeoEye (

Short URL to share this page:

Data Used:
SeaStar/SeaWiFS 1997-2000
Nimbus-7/CZCS 1979-1986

DLESE >> Biological oceanography
DLESE >> Chemical oceanography
SVS >> Chlorophyll
DLESE >> Ecology
DLESE >> Hydrology
SVS >> Plankton
GCMD >> Location >> Atlantic Ocean
GCMD >> Location >> Pacific Ocean
NASA Science >> Earth

GCMD keywords can be found on the Internet with the following citation: Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version

Places you might have seen this:
Aviation Week and Space Technology, Aug. 19, 2002 issue, p. 17