Question 6. In view of the answers to the above questions, what specifically are we 

 measuring- when we use the IRT over water? 



It was concluded that what is being measured is the temperature of the upper 0.1 

 mm. of the body of water as modified by attenuation, sky reflection, water vapor, and dis- 

 persed liquid water. (This excludes sources of variation introduced by the instrument it- 

 self, such as cavity or lens temperature, or that of the atmosphere itself between air- 

 craft and water, which becomes important if the lens system does not have appropriate 

 spectral selectivity). 



Question 7. What are the limits of accuracy of data collected with presently avail- 

 able infrared equipment in predicting microsurface temperatures, bucket temperatures, 

 and mixed layer temperatures ? 



It was concluded that the microsurface temperature can be estimated within ±0.5°C. 

 with proper use of the IRT equipment. It was also concluded that with adequate supple- 

 mentary data bucket temperatures could be estimated within 1.0°C. from IRT microsurface 

 temperatures. This requires that corrections or adjustments be made which require 

 specific knowledge of the effect of meteorological conditions on the difference between 

 microsurface and immediate subsurface temperatures. Data are now coming to hand from 

 which predictions of the heat budgets and transfers can be made but a considerable ex- 

 pansion of effort in collecting these data is required. Some differences as large as 3.0°C. 

 remain unrationalized, but it is thought these could have been caused by operational error 

 or extreme microsurface gradient for which no correction data are available. 



It was concluded that mixed layer temperatures could be predicted to some useful 

 extent, nominally ±3.0°C. Useful estimates of the temperatures of the mixed layer from 

 IRT records can be obtained if knowledge is at hand on prevailing gradients from surface 

 to the thermocline for the specific locality and season involved. This information is a 

 matter of record for many areas from existing bathythermograph data. 



Question 8. What can be done to standardize the collection, reporting, processing , 

 and storage of IRT data and expedite its retrieval and dissemination ? 



The National Oceanographic Data Center agreed to take this question under advise- 

 ment and to prepare a proposal. 



Question 9 . What are the best uses to which the presently available IRT data can 

 be put ? 



For deep sea oceanography, IRT data are useful in detecting horizontal gradients; 

 the value of absolute temperature readings is doubtful, since accuracy of ±0.1°C. or 

 better is often required. There may be more useful applications for physical studies in 

 the shallow areas where hydrographic features can be more readily interpreted from sur- 

 face thermal patterns. 



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