3 
RESEARCH 
USERS' PANEL 
REPORT 
Panel Chairman: 
Dr. Otis B. Brown 
Contributors: 
Mark Abbott 
Robert Arnone 
Stephen Colgan 
Peter Cornillon 
Curtiss Davis 
Frank Eden 
Richard Eppley 
Catherine Gautier 
Mary Hughes 
John Kermond 
Charles McClain 
Erik Mollo-Christensen 
Eni Njoku 
Mary Jane Perry 
Mike Reeve 
William Sackett 
Raymond Sambrotto 
Raymond Smith 
John Steele 
Fran Stetina 
Phillip Taylor 
Ron Tipper 
Paul Uhlir 
John Walsh 
Stan Wilson 
Joe Wroblewski 
Charles Yentsch 
James Yoder 
Background 
Photosynthesis by land and ocean plants converts 
carbon dioxide into plant tissue and is one of the most 
important natural processes that removes carbon diox- 
ide from the atmosphere and oceans. Marine phyto- 
plankton are responsible for at least 30% of the total 
global photosynthesis, and recent studies suggest that 
phytoplankton photosynthesis may be underestimated 
by a factor of two. Phytoplankton photosynthesis is a 
key process in controlling the biogeochemical cycles of 
carbon, nitrogen, phosphorus, sulfur, and oxygen. 
These elements play major roles in controlling the glo- 
bal environment, and understanding their cycles is a 
major goal of the emerging field of Earth System 
Science. 
Phytoplankton contain chlorophyll and other pig- 
ments that capture sunlight, which provides the energy 
required for the photosynthetic process. Chlorophyll is 
a green pigment, and the color of water changes from 
blue to green as the concentration of phytoplankton 
and, hence, chlorophyll increases. As a result, phyto- 
plankton concentration and, thus, the photosynthetic 
potential of ocean waters can be estimated in most of 
the global ocean by measuring ocean color. As dis- 
cussed in Section 1, the possibility of measuring the 
photosynthetic potential of the sea from a satellite- 
borne sensor led to a ‘proof-of-concept’ mission, the 
Coastal Zone Color Scanner (CZCS) on the Nimbus-7 
satellite. 
Once oceanographers verified the chlorophyll dis- 
tribution patterns revealed by CZCS imagery, the use of 
the imagery revolutionized biological oceanography. 
For the first time, oceanographers could obtain meas- 
urements of a biological property over large areas of 
the ocean. The concentration of phytoplankton varies 
greatly in space and time because the growth medium, 
water, is in constant, three-dimensional motion. Until 
CZCS imagery was available, biological oceanogra- 
phers were generally restricted to studying relatively 
small-scale phenomena, since ships cannot cover 
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