SKCT. 2] 



LARGE-SCALE INTERACTIONS 



257 



low-lying coastal stations. The author estimated that isobaric curvature should 

 cause the geostrophic approximation to overestimate advection by about 13%, 

 which leads roughly to a 20% overestimate in the net source. The time integra- 

 tion was made in this term by computing it at twice daily intervals and 

 averaging. 



(iv) The region was subdivided vertically, using Fig. 74 as a guide, into 

 three layers : surface to 900 mb, 900-700 mb and 700-500 mb. 



mb 

 850 



Vladivostok 



FukuokQ Yonogo Wajimo Akita Sapporo Wakkanoi 



(a) 



Fukuoka Yonago Wajimo 

 (b) 



Akita 



Sapporo 



Fig. 74. Some vertical properties of the atmosphere during the cold air outbreak over the 

 Japan Sea. (After Manabe, 1957, Fig. 5.) 



(a) Distribution of the height of the inversion base over both sides of the Japan 

 Sea (see Fig. 72). 



(b) Cloud distribution along the west coast of the Japanese islands. Cu stands for 

 cumulus, Ac for altocumulus and Ci for cirrus. Approximate coverage indicated by 

 the fractions where obtainable. 



The basic steps in both budgets were to determine the total source term as 

 the difference between horizontal and vertical advection, then to evaluate 

 radiation and precipitation independently, finding the ocean fluxes as residuals. 



The vertical advection term was obtained by integrating the actual wind 

 vectors at the surrounding observation stations throughout the period and 

 computing the average divergence at the various levels ; thus, from continuity, 

 the vertical profile of the mean vertical velocity over the Japan Sea during 

 the period was obtained. The results are shown in Fig. 76. Since the wind data 

 began to give out above 700 mb, it is not clear how the average advective 

 transport through the 500-mb surface was obtained, although Fig. 76 and 

 common meteorological experience in similar situations suggest subsidence of 



