129 



rain in such a region in 1 day would represent a release of about 3OOO cal 

 cm'^day"-'-. While the greater fraction of water vapor represented in such 

 an energy conversion must be due to horizontal advection, a significant 

 amount could be accounted for by the transfer processes taking place within 

 such a region. The distribution of sensible heat transport is eimilar to 

 that of the latent heat transjKJrt, with the exception that strong gradients 

 coincide with the boundary between disturbed and undisturbed states . Since 

 this is the boundary between the regions of maximum and minimum cloudiness 

 and weather, maximum values of Qs are found within the disturbed region. 

 Values of Qs in excess of 36 cal cm"^day'^ are observed over a wide crescent 

 around the center of the disturbance. This means that maximum convective 

 instability should be concentrated within this region. Total energy Q is, 

 therefore, at a maximum within this region, exceeding 650 cal cm'^dayl in 

 the northern quadrant of the storm. The distributions of Qe and Qs for the 

 second example are shown in Figures 11 and 12. The main features are un- 

 changed, but there is considerable increase in the size of 1;he transports. 

 Latent heat transport reaches a majcimum of ikkS cal cm'^day"^, and sensible 

 heat transport, fQ cal cm'^day"-'-. These values can be compared with the 

 maximum values computed by Petterssen, et al., (1962) from typical winter 

 cases of cyclones in the western North Atlantic. Maximum values of l^i-ii-O cal 

 cm"2day"l for latent heat flvtx and 720 cal cm~2day~l for sensible heat flux 

 were obtained. Pyke (196^) computed values for a cyclone in the Gulf of 

 Alaska and obtained values of 350 cal cm" day"-*- for Qg and 2l6 cal cm'^day"-^ 

 for Qs* Malkus and Riehl (1959) > assuming equations essentially the same 

 as (1) euad (2), computed latent and sensible heat fluxes for a moderate 

 hurricane within 90 km of the center of 2*4-20 cal cm'^day"-*- and 720 cal 

 cm'^day''^. Consistent with the above, they assumed small changes in qs - qg,, 

 a decrease of 5-2 g kg"^ in the region 90 to 70 km to 3.5 g kg-1 50 to 30 km 

 from the center. Thus the increase in latent heat from the values observed 

 in the above disturbances and in the trade wind regions is due to an increase 

 in wind speed. They assumed a constant sea-air temperature difference of 

 2.0c. This they ascribe to adiabatic expansion during horizontal motion 

 toward lower pressure rather than the cooling mechanisms called upon in the 

 above disturbances. This large aT , together with high wind speeds, gives 

 a large sensible heat transfer. In comparison with this value, the highest 

 hourly mean value of Qs observed on the CRAWFORD was 201 cal cm~^ day"-''-. 

 The values utilized by Malkus and Riehl for the moderate hurricane are, 

 therefore, quite consistent with those values computed from the composite 

 storm data. In turn, these are consistent with values of latent heat trans- 

 fer computed for higher latitudes. The values of sensible heat transfer 

 appear, at the most, to be UO percent of the values observed at higher 

 latitudes where pronounced sea-air temperature differences are observed. 



Figure 13 shows the observed values of latent and sensible heat transfer 

 every 2 hours through a composite streamline field of an equatorial vortex 

 encountered during the I963 cruise. Latent heat flux ranges from 252 to 938 

 cal cm'^day"-'-, while sensible heat flux ranges from -2 to 201 cal cm"^ day"-^. 

 Regions of maximum and minimum transfer coincide with the distribution noted 

 in the composite models presented in Figures 5 through 12. 



