time as much as one second or more. In example 1 of figure 7, this time interval corresponds 

 to about 500 feet along the flight path at a time when the recorded temperature was changing 

 about 1.5° F. As with the test measurements made at ARGUS ISLAND, these results are at 

 best only approximations. More exact comparisons are possible only if much faster chart 

 speeds are used and if thermal signatures from the ship or tower are recorded. 



Examples of gradients observed by the ART are shown in figure 8 through 12. Figure 

 8 shows synoptic data collected during an 8 -hour survey over the Tongue of the Ocean and 

 Exuma Sound on 9 February 1963. Temperatures were averaged over 1 -minute intervals 

 corresponding to distances of about 3.5 miles. Figure 9 shows a proposed analysis of the 

 data indicating generally strongest sea surface temperature gradients along the edges of the 

 Tongue and the Sound. 



A further example of temperature gradients observed by the ART is shown in figures 

 10 and 11. Figure 10 shows the flight tracks in an area southeast of the Gulf Stream covered 

 by four flights between 8 and 11 April 1963. The proposed analysis of the data collected dur- 

 ing these flights is shown in figure 11. Sea surface temperature gradients along the track 

 exceeded 0.3 °F per mile at several locations. 



The last example of gradient detection by ART is shown in figure 12. The gradient at 

 the edge of the Gulf Stream was about 10 °F per mile. 



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