100 



The interaction between exchange and air circulation has been re- 

 emphasized in this last discussion. The patterns of exchange are intently 

 somewhat different in the equatorial trough zone from what they are in the 

 trades - their relations to convective clouds and cloud distributions are 

 also strikingly different. 



The fluxes themselves are more variable in the trough zone than in 

 the steadier trades. Frequent disturbances dominate the scene here, 

 particularly in summer. By producing large clouds, these disturbances 

 provide the mechanism which make the main product of sea-air exchange 

 (moisture) usable in the atmosphere. 



In the trough zone, another imprint of the disturbances is the much 

 increased Qg/Og ratio. The important documentation of why and how this 

 ratio is higher in disturbed zones is taken up by Garstang in the following 

 contribution to these Proceedings . We merely conclude here with two 

 important questions which bridge the two topices; these are: 



1. How do disturbances affect sea-air interaction in the tropics? 



2. What role does sea-air interaction play in the life and growth 

 of disturbances? 



Concerning the first question, the foregoing has already given a clear 

 indication that tropical disturbances are critical in regulating sea-air 

 exchange. Garstang 's work illustrates this in a rather disturbing way, in 

 that the results suggest that we may have to make drastic changes in the 

 accepted climatological exchange picture. This could upset the global 

 budgets and part of oceanography as well. 



In respect to the second question, we have firm evidence that in the 

 hurricane stage, local sea-air fluxes play a large and crucial role in the 

 machinery of the storm's heat engine (Malkus and Riehl, I960). In sub- 

 hurricane disturbances, we do not know what the role of local exchange is, 

 nor do we yet have adequate models to form a framework for such a study. 

 Quantitative observational studies of the sort described in the following 

 paper by Garstang -ftius constitute the essential next step. 



