8 



MANUAL OF MARINE METEOROLOGICAL OBSERVATIONS 



1254. When sea waves and swell waves are distinguished simultaneously 

 at the time of observation, both systems should be reported. At least two 

 (Id-^d^P^vHw) groups should be included in the coded message; the first group 

 containing data for sea waves and the second group swell waves. When more 

 than two wave systems are present, data for each system of waves should be 

 included in the coded report. Code each system separately and enter each 

 code group in the column headed "waves" on Form 615-5. In cases when more 

 than two wave systems are observed, enter the additional wave groups to right 

 under REMARKS. 



Table 1-1. --Elements of the Code 



Symbols 



Definitions of symbols 



Observing 

 Instructions 

 (Par? No.) 



Coding In 

 structions 

 (Par. No.) 



Code 



Table 



No. 



Y 



Q 



L'o^o^o" 

 GG 



N 



dd 



ff 



VV 



WW 



W 



PPP --- 



TT 



Nh 



Cl 



h 



Cm 



Ch 



Ds 



Vs 



a 



pp 







TsTs--- 

 TdTd— 



1 



dw^w"-" 



Pw 



Hw 



ICE 



C2 



K 



D. 



r 



e 



Day of week 



Octant of globe 



Latitude In degrees and tenths- 



Longitude in degrees and tenths 



Greenwich civil time of observation, to nearest hour 



Fraction of celestial dome covered by clouds 



Direction from which the wind is blowing (tens of degrees) 

 Wind speed in knots 



Visibility (in code) 



Present weather (in code)- 

 Past weather (in code) 



Sea-level pressure (tens, units, tenths) mb . 



Temperature of the air (whole degrees Celsius) - 



Fraction of celestial dome covered Cl or C]^ cloud 



Clouds of types stratocumulus, stratus, cumulus, 



cumulonimbus (in code) 



Height of base of lowest Cl or C^ cloud above sea 



Clouds of types altocumulus, altostratus, nlmbostratus 



(in code) 



Clouds of types cirrus, clrrostratus, cirrocumulus (in 



code) 



Ship's course (In code) 



Speed of ship in knots (in code) 



Characteristic of barometric tendency (in code) 



Amount of barometric change (units and tenths) mb . 



Group designator 



Difference between air and sea temperature ( half degrees 

 Celsius) -- 



Temperature of dew point (whole degrees Celsius) 



Group designator 



Direction from which waves are coming (tens of degrees) 



Period of waves (in code) 



Mean height of waves (in code) 



Group designator for ice group 



Description of kind of ice (in code)-- 

 Effect of Ice on navigation (In code)- 



Bearing of ice limit (in code) 



Distance of Ice from ship (in code)-- 

 Orlentation of ice field (in code) 



8110-30 

 3110 

 3210 



4101-3 

 5710 

 5810 



6120' 

 7110-20 



8110-30 



8201 



6310-30 

 6310-30 



7133-44 



9101-2 



9210-20 



9310-22 



10120 



10130 

 10130 

 10130 



2201 

 2301 

 2401 



2501 

 2601 



8310 

 3120 

 3220 



4201 



5720-32 



5820 



6410-11 

 7310 



8320 



8340 

 8330 



8350 



8360 



2701 



2801 

 6420-22 

 642 0-22 



7330 

 7310-12 



9420 

 9430 

 9440 



10280 

 10220 

 10230 

 10240 

 10250 

 10260 



9 

 10 



11 



12 



13 

 14 

 15 

 16 



4 

 17 

 18 



19 

 20 

 21 

 22 

 23 



