PROCESSING PROCEDURES 



In the upper right corner (key) is the position 

 file number, "29118," denoting the quadrangle 

 29° to 30° North and 118° to 119° West. 

 Transcribed from the log sheet are the date, 

 time (G. c. t.), name of vessel, speed, latitude, 

 longitude, sounding depth, sea surface tem- 

 perature taken by bucket, wet-bulb tempera- 

 ture, dry-bulb temperature, present weather, 

 state of sea, wind direction, wind force, and 

 type and amount of clouds. Any discrepancy 

 between temperature at the "set-up level" as 

 read from the print and the "set-up tempera- 

 ture" listed in figure 2 is entered as a tempera- 

 ture correction (TC) to the print. Instru- 

 mental corrections which were applied in 

 printing for temperature (TCS) and depth 

 (DCS) are shown. Vapor pressure difference 

 (V. P. Diff.) is calculated from wet- and dry- 

 bulb temperatures, and entere<:l. Additional 

 cpace is provided for any other information 

 which may be usefid in analysis. 



Of the three copies of each bathythermogram 

 print usually made, one is filed by position, one 

 by ship or cruise, and the third is filed in a 

 central agency by position. When large quan- 

 tities of data are available, punch-card systcm.s 

 may be used to advantage. The items to be 

 punched will depend upon the use to be made 

 of the bathythermograph data. 



OTHER CONTINUOUS RECORDS 



In addition to the bathythermograph, several 

 other recordmg instruments are being used for 

 the continuous measurement of temperature 

 and salinity with time or depth. The Mosby 

 "thermo sound" (Mosby, 1943) (2) records of 

 temperature and depth are on round glass slides 

 2K inches in diameter. The temperature-depth 

 trace on the smoked side is read by means of a 

 microscope. Readings are scaled off at standard 

 depths and at inflection points in the tempera- 

 ture-depth curve. Usually 50 to 100 readings 

 are necessary for a detailed tabular record. 

 Both temperature and depth calibration cor- 

 rections must be determined and applied to 

 the readings of individual instruments. The 

 glass slide may be lacquered and filed for a 

 permanent record, or cleaned and resmoked for 

 use again. 



The records of a Salinity-Temperature-Depth 

 (STD) recorder (Jacobson, A. W., 1948) (S), 



or the similar Conductivity-Temperature-Depth 

 (CTD) recorder, are in the form of paper tapes 

 G inches and 12 inches wide, respectively. The 

 three similarly recorded traces (salinity or con- 

 ductivity, temperature, and depth) have indi- 

 vidual scales on the tapes. Salinity and tem- 

 perature are read at selected depths and at in- 

 flection points in the continuous traces, the 

 number of readings varying with the detail 

 required. Corrections for instrumental error 

 must be ai)plied to the readings of all three 

 variables. Values of conductivity and tem- 

 perature may be converted to salinity by means 

 of table XV, page 103. The tape records are 

 filed "accordion fashion" to permit easy access 

 to any observation on the tape. 



D.2.— DETERMINATION OF FINAL VAL- 

 UES OF SERIAL TEMPERATURE AND 

 SALINITY DATA 



INTRODUCTION 



Serial temperature and salinity data are those 

 obtained from a subsurface cast of water bottles 

 arranged in series on a wire, to each of which is 

 attached from one to tlu"ee deep-sea reversing 

 thermometers. The object of processing these 

 data is to obtain temperature, salinity, and 

 depth at the individual points of revei-sal of the 

 bottles, and thence by interpolation to find 

 temperature and salinity at standard depths. 

 Because the slightest variations in properties are 

 significant in the sea, great accuracy is required, 

 both in the instruments and m the methods 

 of processing. 



Temperature in situ is obtained from the 

 reading of a protected reversing thermometer 

 by applying corrections for instrumental error 

 and for thermal expansion subsequent to rever- 

 sal. Depth of reversal is found by comparing 

 the corrected reading of a protected thermom- 

 eter with the corrected reading of an unprotec- 

 ted thermometer (unprotected against pres- 

 sure), which is always paired with a protected 

 thermometer. The depths computed from the 

 difference of the protected and unprotected 

 thermometers are subject to instrumental error 

 and must be adjusted by making use of the wire 

 length and wire angle. Salinity is directly pro- 

 portional to chlorinity, which is determined by 

 titration of the water sample with silver nitrate 



