was -0.07 and o was 0.007 . Corrections were made for the mean 

 errors; accuracies for the unshunted STD comparable to -2CT]yj therefore 

 may be expected in those parts of the water column in which the tempera- 

 ture gradients were small. 



This instrument had pressure-sensitive recording paper which 

 traces a record which is difficult to read and makes it impossible to 

 differentiate the salinity and temperature traces by means of ink color. 

 The depth scale was approximately 30 m/in, which results in too con- 

 densed a record for shallow water, especially in the Arctic. These 

 factors and the requirement to derive sound velocity led to the decision 

 to trace the STD records with a Calma digitizer and carry out conversions 

 and plotting with a computer. 



C . REDUCTION OF DATA 



A relatively complicated computer program, MIZl, was used 

 to convert Calma digitizer tapes to corrected salinities and temperatures. 

 The program also computed sound velocity and sigma-t, patched in RS5 

 data at the surface, filled small gaps between curve segments (where 

 scale changes occurred) and classified the results on 0.3-meter depth 

 increments for output in a continuous sequence. Wilson's equation was 

 used for sound velocity and Knudsen's for sigma-t. Missing data were 

 replaced with zeros, except for the temperatures, which were set to 

 -3°. The outputs were printed and punched on cards. 



After editing the cards for minor errors and arranging the stations 

 in sequence, the cards were used as inputs to programs which produced 

 various plots and finished output on the printer and on magnetic tape. 

 Heading data were introduced on cards before the finished outputs were 

 produced. Missing data were excluded from the plots and were replaced 

 by blanks in the printed data; however, they still appear as zeros and 

 -3's on the tape. 



Approximately ten other computer programs were written to do 

 various housekeeping jobs, produce T-S plots and nested temperature 

 plots , convert conductivities to salinities and produce compatible out- 

 put cards from Beckman conductivity-meter data. 



The plots originally were produced in approximately 10 by 12- 

 inch size except for some nested temperature plots which were longer. 

 There was at first no capability for putting the shallow and deep portions 

 of a multiple lowering on the same plot except for the output of the 

 Beckman meter which routinely was inserted by MIZl. However, there 

 were some Beckman lowerings which had large overlaps and were treated 

 separately. Therefore, 183 station plots were produced from the 163 



10 



