102 OCEAN CURRENTS RELATED TO THE DISTRIBUTION OF MASS 



numerical value of the depth expressed in meters, as is evident from the 

 following corresponding values : 



Standard sea pressure (decibars) 1000 2000 3000 4000 5000 6000 



Approximate geometric depth (meters) 990 1975 2956 3933 4906 5875 



Thus, the numerical values of geometric depth deviate only 1 or 2 per cent 



from the numerical values of the standard pressure at that depth. This 



agreement is not accidental but has been brought about by the selection 



of the practical unit of pressure, the decibar. 



Table 13 



EXAMPLE OF COMPUTATION OF ANOMALIES OF DYNAMIC DEPTH 

 (Station E. W. Scripps 1-8. Lat. 32°57'N, Long. 122°07'W. February 17, 1938) 



Meters or 

 decibars 







10 



25 



50 



75 



100 



150 



200 



250 



300 



400 



500 



600 



800 



1000 



1200 



1400 



1600 



1800 



2000 



3000 



4000 



Temp. 



(°C) 



14.22 



13.72 



.71 



.35 



9.96 

 .38 



8.82 

 .48 

 .30 



7.87 

 .07 



6.14 



5.51 



Salin- 

 ity 



(7oo) 



33.25 



.24 

 .24 

 .30 

 .57 

 .84 

 .98 

 34.09 

 .16 

 .20 

 .20 

 .26 

 .35 

 .42 

 .44 

 .52 

 .54 

 .56 

 .59 

 .64 

 .68 

 .70 



<^t 



24.81 

 .91 

 .91 



25.03 

 .86 



26.17 

 .37 

 .51 

 .59 

 .69 

 .80 

 .97 



27.12 

 .28 

 .36 

 .48 

 .54 

 .59 

 .64 

 .69 

 .76 

 .81 



IO6A3 



315.0 

 305.5 

 305.5 

 294.2 

 215.2 

 185.7 

 166.5 

 153.5 

 145.9 

 136.4 

 125.9 

 109.8 

 95.6 



80, 

 72, 

 61 



55.8 



51.1 

 46.3 

 41.6 

 35.0 

 30.2 



10^5, 



0.1 

 0.2 

 ■0.3 



0.8 

 1.0 

 1.2 

 1.4 

 1.0 

 1.0 

 1.0 

 1.1 

 1.4 

 1.7 



10^5^, 



0.3 

 0.7 

 1.3 

 1.6 

 2.0 

 2.9 

 3.7 



8.9 

 9.8 

 10.3 

 10.8 

 10.9 

 10.8 

 10.8 

 11.7 

 14.1 



10^5 



315 



306 



306 



296 



217 



187 



169 



157 



150 



141 



132 



116 



103 



88 



82 



70 



66 



61 



56 



51 



45 



43 



AD 



.0310 

 .0459 

 .0752 

 .0641 

 .0505 

 .0890 

 .0815 

 .0768 

 .0728 

 .1365 

 .1240 

 .1095 

 .1910 

 .1700 

 .1520 

 .1360 

 .1270 

 .1170 

 .1070 

 .4800 

 .4400 



AD 



(dynamic 

 meter) 



.0310 

 .0769 

 .1521 

 .2162 

 .2667 

 .3557 

 .4372 

 .5140 

 .5868 

 .7233 

 .8473 

 .9568 

 1 . 1478 

 1.3178 

 1.470 

 1.606 

 1.733 

 1.850 

 1.957 

 2.437 

 2.877 



It follows that the temperature at a pressure of 1000 decibars is 

 nearly equal to the temperature at a geometric depth of 990 m, or the 

 temperature at the pressure of 6000 decibars is nearly equal to the tem- 

 perature at a depth of 5875 m. The vertical temperature gradients 

 in the ocean are small, especially at great depths, and therefore no serious 

 error is introduced if, instead of using the temperature at 990 m when 

 computing 8, one makes use of the temperature at 1000 m, and so on. 

 The difference between anomalies for neighboring stations will be even 

 less aiTected by this procedure, because within a Hmited area the vertical 

 temperature gradients will be similar. The introduced error will be 



