Depths of sigma-t, salinity, and phosphate phosphorous at the desired isopleth 

 values were taken from each station graph by referring to the common temperature scale and 

 the temperature-depth curve, and each of these properties was plotted on a meridional section. 

 Temperature sections to the same scales of latitude and depth were drawn for each station 

 line of the cruise from the complete BT data (these were used in the analysis but are omitted 

 here in favor of temperature sections with greater vertical exaggeration). The plots of sigma-t 

 were then placed over the temperature sections on a light table and the isopleths were drawn, 

 allowing the grosser detail of the temperature sections to influence the signna-t sections between 

 stations. The salinity and phosphate phosphorous plots were next drawn over the sigma-t 

 sections in a similar fashion, with their isopleths made as nearly as possible parallel to the 

 isopleths of sigma-t. In view of the extensive adjusting of the characteristic curves to obtain 

 continuity between stations, the interpolated values of signna-t, salinity, and phosphate phos- 

 phorous plotted on the sections were followed exactly during the drawing. 



Values of temperature and salinity at standard depths were taken from the station 

 graphs for use in the computation of geostrophic currents. The values of sigma-t tabulated at 

 standard depths were computed from these temperature and salinity values, rather than read 

 directly from the station graphs. 



The most evident new procedure, that of allowing the BT temperature sections to 

 influence construction of the sigma-t (and thus salinity and phosphate) sections, has been 

 instituted to achieve consistency between the distributions of temperature and density, and 

 internal consistency in the method of analysis. It is certainly not argued that all the detail 

 thus introduced into the density distribution is meaningful from every point of view, but a more 

 accurate presentation of the observed field of density is obtained than by merely drawing smooth 

 curves through the station points. As a practical consideration, it is a great deal easier to in- 

 clude all the larger detail than to set up any arbitrary criterion for smoothing which would then 

 have to be invoked continuously during the drawing of a section. 



The method of mutual adjustment of the station characteristic curves is based on 

 the fact that the ocean is continuous; with the present sampling methods this assistance between 

 stations probably gives a closer representation of actuality than methods treating each station 

 individually. The location of the maxinna and minima of these curves on continuous values of 

 sigma-t from station to station, and the subsequent drawing of the isopleths of the salinity and 

 phosphate sections parallel to the isopleths of sigma-t, are based on the consideration that flow 

 in the ocean normally takes place along surfaces of constant potential density, which are closely 

 approximated by surfaces of constant sigma-t, and that mixing of by far the greatest nnagnitude 

 takes place along these same surfaces. 



Some Results of Hugh M. Smith Cruise 14 



The station pattern for Smith cruise 14 appears in figure 2. The stations along 

 155° W. longitude consisted of casts to at least 1, 000 meters; to permit greater definition of 

 detail in the region of interest the other two lines of stations were mostly limited to the upper 

 700 meters. Figures 3 to 7, describing the section at 155° W. longitude are in the sequence: 

 dynamic topography, geostrophic currents, tennperature, sigma-t, salinity. The second series 

 of figures (8 to 11), describing the section at 180° longitude and the third (12 to 15), describing 

 the section at 169° W. longitude are in the sequence: temperature, sigma-t, salinity, phosphate. 

 Figure 16 presents temperature sections on 155° W. , 169 W. and 180° longitudes, taken on the 

 fishing station lines of John R. Manning cruise 11. 



The numbers and positions of the stations are indicated on each section. For each 

 variable except temperature, the location of every observation carried in the tabulated data is 

 indicated by a spot on the vertical section in question. When there was serious doubt regarding 

 the accuracy of an observation, it was not used in constructing the vertical section, and a foot- 

 note to this effect was entered in the tabulated data. Observations unquestionably in error were 

 dropped from the tabulations. 



