doubt, feeling that they may result more from lack of adequate data and the conse- 

 quent necessity of using primarily climatological techniques, rather than any real 

 knowledge, for many areas, of the typical day-to-day and year-to-year variability. 

 Many meteorologists can remember when conditions in both the tropics and the 

 stratosphere were considered to be highly persistent, with little or no departure 

 from climatology to be expected; adequate subsequent observations have since 

 rudely dispelled these illustions. The extent of coverage and the frequency of 

 observations of SST, which only satellites can make practically possible, probably 

 represents our best and perhaps our only chance for determining the real degree 



of variability of SST. 



20 

 Some work has been done using airborne IR measurements of SST. Errors 



at present are of the order of whole degrees. In a study undertaken by the Sandy 

 Hook Marine Laboratory of the U. S. Fish and Wildlife Service, repeated IR measure- 

 ments of the SST patterns of the middle Atlantic continental shelf were made from 



heights of 200 to 500 feet at approximate two week intervals. Figure 5-10 shovifs a 



21 

 successive pair of these measurements for the nnonth of May, 1964. The data 



are plotted in degrees Farenheit at 1 intervals. It should be noted that here also 



large scale patterns persist, while the smaller scale patterns have changes in the 



two week interval. The absolute temperature in some areas of the maps have also 



changed by as much as 10 F. Of course, this is an area near the western edge of 



the Gulf Stream where significant SST changes are not unlikely. 



Our tests indicate that where there is no general change in the sea surface 



temperature as averaged over an area of reasonable size, the observed IR patterns 



within this area also remain relatively constant; this result seems reasonable in 



terms of scale considerations. This is particularly true of large scale current 



features such as were seen in the Sea of Okhotsk, and in the Western Atlantic 



in Section 5. 1. Only in the coastal waters of Australia was there a complete change 



in pattern, and here there were other influences or possible problems such as a 



generally isothermal sea, a long 2-1/2 day interval, and the use of a nighttime 



case in which the presence of scattered or low cloudiness will always remain a 



possibility. The persistence of the small cold and warm spots off the eastern coast 



of Sakhalin in the Sea of Okhotsk indicated that even small scale features may at 



times change only insignificantly. The only really negative result of these tests was 



the disappearance of the large warm area in the northeastern portion of the Sea of 



Okhotsk. The high level of consistency in the other portions of this same case 



suggests that there may have been either an actual change in SST, or, more likely, 



undetected change in cloudiness or atmospheric absorption. In view of the general 



35 



