66 MANUAL OF MARINE METEOROLOGICAL OBSERVATIONS 



7200. SEA-WATER TEMPERATURE MEASUREMENTS 



7210. GENERAL. The condenser (or comparable) intake thermometer 

 will be read to the nearest 0.1°C. (0.2°F.) at each observation to secure 

 the sea-water temperature. Intake thermometer readings previously entered 

 in the engine room log book will not be used for the weather observation. 



7300. CODING AND ENTRIES OF TEMPERATURE DATA ON FORM 615-5 



7310. AIR TEMPERATURE. Enter the dry-bulb temperatures to degrees 

 and tenths of column 17. Prefix a minus sign (-) when the temperature is 

 below 0°C. Enter the dry- bulb temperature to the nearest whole degree 

 (two digits) in column 16 (TT). If the dry-bulb temperature is exactly between 

 two values, 10.5° for example, increase the values entered in column 16 to 

 the next higher value (11 in this case). 



7311. When the air temperature is below 0°C, the minus sign will be 

 disre^^arded and 50 added to the temperature before entry in column 16. 

 For example, -4.6°C would be entered in column 17 and 55 in column 16. 



7312. When the air temperature is between +0.4°C and -0.4°C the actual 

 value will be entered in column 17 and 00 entered in column 16. 



7320. WET- BULB TEMPERATURE. The actual value of the wet-bulb 

 temperature will be entered in column 18 to degrees and tenths. Prefix a 

 minus sign (-) when the temperature is below 0°C. 



7330. DEW-POINT TEMPERATURE. The value of the dew-point tempera- 

 ture in whole degrees as determined from Table 25 will be entered in 

 columns 30 and 33. When the dew-point temperature is below 0°C a minus 

 sign (-) will precede the actual value in column 30. 



7331. When the dew-point temperature is below 0°C, the minus sign will 

 be neglected and 50 added to the dew- point temperature value for entry 

 in column 33. 



7340. SEA-WATER TEMPERATURE. Enter the temperature of the sea 

 water in degrees and tenths Celsius in column 28. 



7350. AIR- SEA TEMPERATURE DIFFERENCE. The actual difference 

 between the air temperature and the sea temperature will be entered in 

 column 29 to the nearest tenth of a degree Celsius. For example, if the 

 air temperature is 10.7°C and the sea temperature is 8.1°C, (10.7 - 8.1) 

 or 2.6° will be entered in column 29. When the air temperature is less 

 than the sea temperature a minus sign (-) will be entered before the actual 

 value. If the air temperature is 5.5°C and the sea temperature is 6.2°C, 

 (5.5 - 6.2) or -0.7 will be entered in column 29. 



