5 6 STATION NO 



43 STATION NO 

 I I o 



4 5 6 STATION NO, 



apoo 



Figure 15. — Vertical sections of temperature ("O, to 200 m. and to 2,.500 ni., along Cape 

 Cook and Willapa Bay lines, spring 1963. 



other at depth between 20 and 50 m. near 

 shore. Apparently both maxima resulted from 

 surface cooling and vertical mixing which had 

 affected only the dilute water in the upper 20 

 m. Seaward of the .salinity front, the upper 

 50 m. of the water column wa.s isothermal off 

 Cape Cook during both seasons. Southward of 

 Cape Cook the magnitude of the thermocline 

 again increased but by fall had deepened from 

 the range to 30 m. to between 50 and 70 m. 

 in the top of the halocline. Temperature in- 

 versions were more frequent in the fall within 

 the halocline, and the near-shore isotherms 



showed a slight depression or convergence. 

 Vertical sections normal to .shore during fall 

 as in the spring showed the logarithmic de- 

 crease of temperature with depth and the level 

 isotherms in the lower zone extending seaward 

 from the Continental Slope. 



Despite this general uniformity in tempera- 

 ture structure, minor changes did occur in the 

 temperature distribution at 200 m. (fig. 18). 

 The tongue of warmer water (> 7.2° C.) noted 

 during spring changed: it became continuous 

 along the coast, occupied a much larger area, 

 and had a greater maximum temperature dur- 



238 



U.S. FISH AND WILDLIFE SERVICE 



