No upper -air data were available for this area, and of course there were no 

 ship reports. Assuming a large atmospheric attenuation correction of 8 K, and a 

 sensor degradation correction of 2 K, the approximate average temperature of the 



Pass 706 analysis, Z82 K, becomes 292 K. The average August temperature for 



o 15 

 these waters is 298 K. Part of the discrepancy may be due to the relatively large 



minimum nadir angle of 30 found in both cases, and part to the presence of invisible 



ice crystal clouds or atmospheric particulates. 



5. 3. 4 Results of SST Consistency As Compared to Other Studies 



As has been the case in all phases of this feasibility investigation, lack of 

 conventional shipboard SST measurements was a major stumbling block. In this 

 particular series of tests, we have taken repeated looks at a given area at intervals 

 of a day or two, and then checked the resultant IR analyses for consistency. Inherent 

 in the procedure is the assumption that there is consistency to be found. Without 

 simultaneous intensive shipboard measurements, the validity of this assumption 

 is always somewhat subject to question. 



Numerous investigators have studied both the short and long term fluctuations 

 in SST, and their possible causes. Wolff et al indicate that 48 hour changes in 

 temperature, averaged over relatively large areas, may reach — 4 K in areas of 

 sharp temperature gradients. On the average, however, these changes are of the 

 order of — 0. 3 K. It is suggested that these changes in SST are caused predominantly 

 by advection patterns which are large in scale, corresponding in area and time scale 



to atnnospheric disturbances at the surface. These findings are substantiated by 



1 8 

 Chase , who found that warming generally occurred in southwest winds prior to 



the passage of a cold front, while cooling occurred in northerly winds after the 



frontal passage. 



During the discussions which led to the "Recomnnendations of the Panel on 



19 

 Sea Surface Temperature" of the Conference on the Feasibility of Conducting 



Oceanographic Explorations from Aircraft, Manned Orbital, and Lunar Laboratories, 



several of the oceanographers present stated that, over large areas of the oceans, 



day-to-day changes in SST, and also year-to-year changes for the same calendar 



month, are considered to be so small that they place greater credence in a climato- 



logical value than they do in direct observations from any single ship. It was these 



opinions that led to the stringent requirements for accuracy of satellite-observed SST, 



19 

 to fractions of a degree C, which are stated in the Recommendations. Our meteor- 



ological experience, however, leads us to presently view these opinions with some 



34 



