INTRODUCTION 



The observations are usually made once each weekday at whatever 

 time the observer attends the tide gage. At some stations situated 

 within or near the entrance of an estuary, the temperature or density 

 varies with the stage of tide or with the direction of the tidal current. 

 It may be assixmed that in the course of a month or more the distribu- 

 tion of observations is fairly uniform over all phases of the tide. 



The monthly temperatiore summaries given in Table 2 are from records 

 of recording thermometers. The thermometer bulb at each station was at 

 a fixed position just below lowest observed low water, so that during 

 a day it was covered by varying amounts of tidal water. The instrument 

 record is in the form of a continuous trace; the mean values are from 

 hourly readings. When it could be done with reasonable certainty, 

 warmest and coldest values are shown for months for which the record 

 was only partially complete. 



The mean temperature and density curves are derived from the 

 monthly means given in Table 1 and show graphically the seasonal varia- 

 tion for many places. The unusual shape of the temperature curve for 

 Daytona Beach and Canova Beach reflects the upwelling that occurs along 

 this section of the coast during the summer months. 



For some practical uses of density data, it is more important to 

 know the density at the temperature apt to be encountered than at the 

 standard temperat\ire. The graph. Sea Water Density at Various Tempera- 

 tures, provides means for converting density at 59°P (l5°C) to density 

 at other temperatures. 



The following National Ocean Sxorvey publications on sea water 

 temperatures, salinities, and densities are also available: 



NOS Publication 31-3, Surface Water Temperature and Density, 



Pacific Coast, North and South America & Pacific Ocean Islands 

 (Third Edition) 1970, $1.00. 



C&GS Special Publication No, 298, Sea Water Temperature and Density 

 Reduction Tables, 19^3 > 2^ cents. 



