The selection of resistance thermometers for temperature sensing 

 was largely a matter of convenience. Thermometers and recorders 

 were readily available and the normalized readout on a scaled strip 

 chart promised a reduction in data processing effort. The main 

 objection to the type of resistance thermometer used for this application 

 is its long time constant as compared to those of other temperature 

 sensors currently on the market. In the course of the TT4 field 

 program, a step change calibration of the temperature recording 

 system was accomplished by transferring the thermometers from a 

 water bath at 18.5°C to a bath at 1.5°C. The lack of experimental 

 control, normal to the laboratory, precluded exact determination of 

 the response deviation from the exponential relationship, 



T(t) = T 1 - (T 2 - TjJe-t/T, (1) 



where T(t) is indicated temperature at time t, Tj is the initial ambient 

 temperature, T^ is the secondary ambient temperature, and r is 

 the so-called "time constant." The results of field calibration indicated 

 that the actual response curve differed from Equation (1) with 

 t becoming larger with increased time after the step change. It 

 appeared that an equivalent time constant of about 60 seconds could 

 be realistically taken for the system used in these studies. 



In addition to fixed-level water temperature measurements, a 

 variety of supplementary observations was made. Bathythermograph 

 drops were made at the tower at intervals varying from hourly to 

 daily. Many 15- to 30-minute surface wave records were obtained 

 with a 15-foot resistance-wire wavestaff. Wind records were 

 continuously recorded from an anemometer mounted on a bracket 

 about 30 feet above the water surface on the hydrographic guide 

 cables. Attempts to measure ocean currents with Roberts current 

 meters were generally unsuccessful except for a 3-week period 

 in April I960 when a "Modified Roberts Current Meter II" furnished 

 by Marine Advisers and Pruitt Manufacturing was used. These 

 data are tabulated in Appendix I. Water samples at 3 to 6 levels were 

 taken periodically during the spring for salinity analysis. Routine 

 weather observations by Air Force weather observers rounded out 

 the field program. All of these data are on file in the Oceanographic 

 Prediction Division of the U. S. Navy Hydrographic Office. 



