follows the choice of the appropriate upwell- 

 ing site. Contour maps are produced from 

 the data which describe the field of the vari- 

 ables measured. Multivariant analyses are 

 also possible from these data, but up until now 

 a severe limitation to understanding the total 

 field was imposed because the data were only 

 two-dimensional. 



The Underway Pumping System — The proj- 

 ect now has an improved pumping system 

 which enables continuous sampling in the 

 vertical dimension as well as from the surface 

 water (Figure 25). The pumping system con- 

 sists of a towed body (fish) complete with 

 pump and sensors, jacketed conducting cable 

 and hose, and a launch and retrieval reel. 

 The sensors read salinity, temperature and 

 depth. The pump provides water for ship- 

 board analysis of nutrients and fluorescence. 



The fish can operate at any depth down to 

 100 meters (the bottom of the euphotic zone 

 in the eutrophic regions) and is controlled 

 from the ship by manual or automated sig- 

 nals. The maximum towing speed is 14 knots, 

 and the normal speed is 10 knots. Data from 

 the towed fish make it possible to describe the 

 vertical, as well as the horizontal, fields of 

 measured variables. The vertical field descrip- 

 tion would otherwise have to be interpreted 

 from bottle casts, which supply fewer data. 



CUEA Computing System — The study of 

 ecosystem dynamics requires a highly respon- 

 sive technological capability. Typical of the 

 commitment of the CUEA program to respon- 

 sive and flexible technology is the shipboard 

 computing system (Figure 26), the Interactive 

 Real-Time Information System (IRIS), which 

 represents an innovative advance in oceano- 

 graphic research. 



TOWED UNDERWAY 

 PUMPING SYSTEM (TUPS) 



Figure 25 The Towed Underway Pumping System (TUPS) will provide continuous data in 

 real time from any depth up to 100 meters with the ship underway at up to 12 knots. 

 Together with the continuous surface sampling system, TUPS will allow CUEA scientists to 

 define the three-dimensional fields of important variables such as temperatures, chlorophyll 

 and the nutrients. 



42 



