of the Gulf Stream. This process was unknown 
until CZCS imagery was available. Statistical 
techniques are currently under development 
that can be applied to satellite thermal and color 
data to better quantify ocean flow fields. Con- 
current and coregistered AVHRR and CZCS im- 
agery can also be used to study and statistically 
describe mixing between two different water 
masses. 
Studies of Global-Scale 
Processes 
The recent widespread distribution of CZCS 
imagery in the oceanographic community has 
stimulated ambitious plans for oceanographic 
Figure 17. A composite 
CZCS image showing the 
distribution of chlorophyll 
in the global oceans dur- 
ing December, 1981. 
High concentrations (over 
4 ug/l) of chlorophyll 
(phytoplankton) are indi- 
cated by orange and red, 
whereas low concentra- 
tions (less than 0.5 ug/l) 
are indicated by blue. 
(Courtesy of GSFC and the 
Univ. of Miami) 
studies in the 1990s. For example, scientists in 
the United States and abroad are planning the 
Global Ocean Flux Study (GOFS) to better quanti- 
fy the ocean's role in the global carbon cycle and 
other major biogeochemical cycles. Ocean-color 
measurements are required to implement the 
scientific strategy of GOFS and other programs 
whose goals include the study of primary produc- 
tion on a global scale. Acquisition of data on 
ocean color is the key to the success of these 
studies, because these data are the only global 
measure of ocean biota that can be obtained 
within a relatively short period of time (days). Fig- 
ure 17 is an example of the global images that 
can be obtained from satellite ocean-color meas- 
urements. 
27 
