MEAN CLOUDIKKS 

 (Code 3-5) 



CLEAR KK ]i« 

 (Code 0-2) 



CUXDI SKIES 

 (Code 6-8) 



TABLE 2 



MEAK RADIATION FOR VARIOUS CLOUD COVERAGE 

 (gra cal/cin2/hr) 



HOUR (Z) 



08-09 09-10 10-U 11-12 12-13 13-1'* 1^-15 15-16 16-1? 17-18 18-19 

 0.31 5.U0 18.63 34.05 50.97 61.84 61.26 65.52 60.46 56.47 42.38 

 0.10 1.11 1.80 2.19 1.92 1.71 2.11 2.44 2.06 2.18 2.4o 



19-20 20-21 21-22 TOTALS 



23.51 8.71 0.5T 490.08 



2.U 1.22 0.16 23.51 



I-R 00.21 4.29 16.83 31.86 I19.05 60.13 59.15 63.08 58,40 54.29 39.98 21.40 7.49 0.41 466.57 



I 0.48 9.64 29.41 48.93 75.82 78.II 87.12 8o.64 

 R 0.11 1.18 2.66 2.63 2.99 1.77 2.47 2.20 



60,53 71.37 ?r.66 



1.64 1.91 3.20 



34.56 15.24 1.24 670.75 

 2.50 2,64 0,08 28.00 



I-R 0.37 8.46 26.73 46.33 72.83 76,34 84.65 78.H 78.89 69,46 54.46 32.06 12.60 I.16 642.75 



I 0.14 1.61 4.89 9.98 12.84 31.67 36.56 28.07 27.55 31.40 28.87 

 R 0.05 0.08 0.22 0.4o 0.49 0.82 1.57 0.85 0.69 1.18 0.73 



0.09 1.53 4.67 9.56 12.35 30.05 35.00 27.22 26.86 30.22 28.14 8.04 3.80 O.U 218.66 



8.39 3.89 0.11 226.16 

 0.35 0.09 0.00 7.52 



I • Incident radiation 

 R • Reflected radiation 

 Cloud Codes are WMO Code 60 



A supplemental table (table 2) constructed from these data contains 

 mean radiation values for varying cloud coverage. The average radiation 

 received each hour (incident minus reflected) is considered to represent 

 average cloud conditions ("WMO Code 6o, Codes 3-5) • The three highest 

 radiation values and the three lowest radiation values can be considered 

 approximations for clear or nearly clear skies (Codes 0-2) and for cloudy 

 or nearly cloudy skies (Codes 6-8), respectively. The mean temperatures 

 of the vater column are calculated by sorting and averaging the obser- 

 vations. Actual heat changes in the vater column csui then be compared 

 vith available radiative energy, and the other terms in the heat budget 

 equation can then be calculated. 



Table 2 shows that the mean daily total energy available for absorp- 

 tion in the water amounted to h66.^'J gm cal/cm^/day. If no heat gain or 

 loss is assumed to occur in the upper 100 feet of the ocean at this time 

 of the year, then the outgoing radiation averages 466.57/2^ hours or 

 19.44 gm cal/cm2/hour. The assumption of zero local heat change at ECHO 

 is based on data for a 5-year period (I950-I954 and i960) (reference 6). 



Figure 2 shows the approximate hourly heat exchange as deduced from 

 the mean hourly values in table 2, assuming a constant heat loss of 19.44 

 gm cal/cm^/hour from the sea surface. Qg is positive for 10 hours on 

 essentially clear days (represented by the average of the three highest 

 hourly readings) for 9 hours on partly cloudy (average) days and for 6 

 hours on cloudy days (average of the three lowest hourly readings). 

 Figiire 2 assiimes that the sea emits long-wave radiation with 100-per- 

 cent efficiency as a black body. 



