Use of either system for collecting oceanographic data from a 

 satellite presents the problem of extensive atmospheric interference. 

 In the case of the radiation thermometer, the data from higher alti- 

 tudes indicate a formidable problem. Corrections -would change with 

 daytime and nighttime observations and with meteorological conditions. 

 Observations could not be made during rain, fog, or cloudy skies. 



The altitude effect is not as important for the infrared scan- 

 ner. The NIMBUS II infrared scanner, for example, could detect the 

 Gulf Stream when skies were clear (wilkerson, 19^1)* The Reconofax 

 IV infrared scanner was used in this experiment. Similar experiments 

 should be performed with later model scanners. Data should be ac- 

 quired at various altitudes over other strong currents, such as the 

 Kuroshio and Agulhas Currents, to determine if these currents can 

 be defined as easily as the Gulf Stream. 



Radiation thermometer data should also be acquired from high 

 altitudes over a surface vessel equipped with a radiation thermometer 

 in order to determine water vapor corrections for high-altitudes. 



Dye Tests 



Description 



The primary objective of the dye experiment was simultaneous 

 sampling and photographing a Rhodamine-B dye patch with different 

 filters and films to determine the optimum combination for maximum 

 contrast between dyed and undyed water. 



A secondary objective was determination of which characteristics 

 of a water mass can be measured from a time series of aerial photo- 

 graphs of dye. During the photography, changes in dye concentrations 

 were monitored with a fluorometer from a small boat so that the re- 

 lationship between area and concentration could be calculated. Water 

 samples collected hourly after the dye release were analyzed for dye 

 content. By tracing the movement and concentration of the dye patch 

 with the boat and by continuously recording wind and currents at ARGUS 

 ISLAND, the measured characteristics of the surface circulation were 

 related to the time series of photographs. 



Results 



Figure Ik shows dye patch photographs in the nine frequency bands 

 of the Itek camera. The greatest contrast occurred in band h. This 

 band has maximum sensitivity at O.560 micron and extends from 0.550 to 

 0.620 micron (cutoff based on 1-percent transmittance levels). Thus, 

 the maximum separation of the reflectance spectra of sea water and sea 

 water containing Rhodamine-B dye occurs near O.560 micron (the yellow- 

 green region ) • 



Examples of photographs from the RC-8 camera are shown in figure 

 15* These photographs were taken at intervals of 0.2, U.3, 32. 9 > and 

 259.9 minutes after dye release. The irregular nature of the flow is 

 evident . 



23 



