FfB MAR APR MAY JUNE JULY AUG SEPT 



500 

 550 



FIGURE 17 MEAN MONTHLY MIXED LAYER DEPTHS FOR PACIFIC WEATHER SHIP PARA, 50°N.,I45»W, 



cline is sometimes still in evidence and at the same time the 

 new, shallow thermocline is forming, A mean beti^reen the two 

 would not only be unrepresentative of actual conditions, but 

 would give the impression that there is continuity to the curve 

 of mean monthly layer depths. Naturally this is not the case; 

 one thermocline is distinctly different from the other, 



b. Monthly or lunar variations - In working with time- 

 series BT data, it was noted that long period fluctuations seem- 

 ed to exist with periods suggestive of monthly oscillations, and 

 superimposed on the seasonal variations, as illustrated in figure 

 18, It was considered that, if such fluctuations actually exist, 

 they cannot be attributed to turbulent mixinf, caused by winds or 

 sea. Although turbulence will cause an Increase in the depth 

 of the thermocline, there is no reason to expect the therriocline 

 to rise gradually when the wind or sea subsides. Instead, the 

 original thermocline should reii:ain deep after the turbulence 

 ceases, and v/ith renewed m.ixing by vjind and sea, a new mixed 



40 



