Winterfeld also found that simultaneous BT and bucket thermometer 

 sea surface temperatures generally were in agreement, and that no 

 large variations were evident. This implies that bucket temperatures 

 are more accurate than injection temperatures for use as BT reference 

 temperatures. 



Saur (reference 5)> after comparing 6,826 pairs of bucket and 

 injection temperatures, reported that injection temperature obser- 

 vations varied erratically among ships, cruises, and on individual 

 ships at different speeds. These results indicated that injection 

 temperatures average about 1°F higher theui actual surface tempera- 

 tures. Injection thermometers from five ships were in error as much 

 as 3.9°F. 



Undoubtedly, an injection temperature used as a reference to 

 correct BT bias introduces considerable error. The BT is subject 

 to additional errors: (l) delay in temperature response, (2) lim- 

 ited accuracy of temperature and pressure sensing elements, (3) tem- 

 perature errors introduced by the pressure element lag, (k) error 

 due to the field operator, ( 5) errors Imposed by the corrections 

 applied during processing of the slide, (6) Inaccurate grid calihra- 

 tion, and (7) reading, coding, and key-punching errors. 



The relationship between the overeuLl error and its various com- 

 ponents can be written as follows: 



E = ^{ AE-l)2 + ( AEg)^ + ( AEy)^ 



where AE represents various errors. 



This study is designed to determine the magnitude of these errors. 



OBSERVATIOML PROGRAM 



The data used in this report were obtained aboard U.S. Coast 

 Guard cutters during five cruises to OWS DELTA (UUN, UlW) and three 

 cruises to OWS ECHO (35N, U8w) . The dates for each patrol are indi- 

 cated in table 1. During each 3-week cruise, routine BT observations 

 were taken. In addition, oceanographic stations taken at OWS DELTA 

 provided useful comparative data for this analysis. Several types of 

 observations were taken specifically for this study. Paired BT ob- 

 servations were taken during ECHO cruises 1 euid II and DELTA cruises 

 I and II. 



During DELTA II and III injection temperatures were read by an 

 oceanographer. During all cruises injection temperatures were read 

 by the ship's engineer. 



