4. LARGE-SCALE INTERACTIONS 



JOANNK S. Ma I. K US 



Dedication and Acknowledgements 



This effort is dedicated to Columbus O'D. Iselin to whom the writer owes 

 her interest in the sea, and her opportunity to pursue it without restriction. 

 His efforts have provided a stimulating atmosphere of broad inquiry into the 

 earth sciences and a group of lively and productive interacting individual 

 colleagues without whose experience and participation such an ambitious 

 endeavor could not have been undertaken. His glorious confidence in us all 

 has given each of us the necessary self-confidence to tackle difficult problems 

 while at the same time his own humility in the face of the sea's complexity 

 has imbued us with the necessity of continuous self-criticism in our attempts to 

 understand its behavior. 



Among those colleagues who have been particularly helpful in the prepara- 

 tion of this review are Henry Stommel, Andrew Bunker, Kirk Bryan, Jr., 

 Herbert Riehl and Jose Colon. 



Miss Margaret Chaffee made a large number of the calculations and ably 

 undertook the drafting, while the manuscript was typed by Mrs. Mary C. 

 Thayer, who went far beyond the call of duty in its execution. 



1. Introduction 



The links connecting the atmosphere and oceans are intimate, multifarious 

 and vital to the operation and the understanding of each. Most obvious is the 

 physical proximity, contact and mutual exchange of motion, heat, water, salt, 

 gases, pollutants and biological organisms. The wind systems of the atmosphere 

 are solar-powered mainly through the intermediary of the sea ; the water-vapor 

 fuel, picked up by the trade winds over the sun-warmed tropical oceans, is itself 

 converted from latent to usable form by another intervention of marine in- 

 fluence — giant salt particles which collect the tiny cloud drops in the towering 

 equatorial clouds and allow them to fall out as rain, leaving the released heat 

 air-borne and available for transport. The rough waves of a choppy sea act to 

 brake the winds which build them and remove their momentum, but this same 

 drag is recognized by the oceanographer as the main transporter of water 

 masses, driving the huge ocean-current systems of the globe. The oceans thus 

 regain through wind stress a small fraction of the energy they supplied in 

 evaporated water to the air, and one large circuit in the complex coupling of 

 the two systems is complete. The tiny ratio of energy fed back from air to sea 

 might suggest a stable and uninteresting interaction, except for the enormous 

 heat storage capacity of hydrosphere compared to land or air. Small changes in 

 ocean circulation may significantly alter the atmospheric energy sources, 

 permitting internal instabihties and possibly amplifying fluctuations, as will 

 be suggested later. 



Another link is that both media are turbulent, differentially heated fluids in 



[MS received September, I960] 88 



