260 



[chap. 4 



direct absorjDtion of insolation was obtained from a nomogram of Yamamoto 

 and Onishi (1952). As cloud albedos, 78% was adopted for cumuliform and 

 65% for the stratus type. The work of Hewson (1943) was used to estimate 

 transmission inside clouds. As it turns out in this case, the radiation term is a 

 very small one in the final balance compared to the advective and Qs terms 



mb 

 500 



600 



700 



800 



Surf, 



I 



-0.1 



mb 

 500 



800 



900 



Solar 

 Radiation 



Long-Wove 

 Radiation 



Cooling or Heating 



due to 



Long -Wove Rodiotion 



over the Sea near Wajima 



Cloud layer 



-"^^T^- 



-0.5 



0.5 

 col /g day 



ID 

 °C/doy 



(a) 



Fig. 77. Results of radiation computations for mean air structure prevailing during the 

 cold air outbreak. Vertical co-ordinate pressure in mb. (After Manabe, 1957, Figs. 13 

 and 14.) 



(a) Left : Mean vertical distribution of heating due to absorption of incoming solar 

 radiation. Right : Mean vertical distribution of heating and cooling due to long-wave 

 radiation. Unit : cal per gram per day. 



(b) Long-wave radiation computation repeated using thinner air layers. Unit: 

 cooling or heating of the air in °C per day. 



which dominate. The figure for average net radiational cooling for the layer of 

 93 cal/cm2 per day, or about 0.8°C per day, is in good agreement with the results 

 of other studies. 



Likewise the precipitation term, although uncertain, is very small. During 

 such outbreaks of cold continental air, commonly only showers or snow flurries 

 occur. Here the precipitation was estimated from the coastal stations and many 

 islands to be about 1.3 mm per day, corresponding to an LP warming of 

 77 cal/cm2 per day for the layer. The final results of the budget study are 

 summarized in Fig. 78 and Table XXII ; in the latter, they are compared with 



