195 



The general positions of the oceans' major 

 current systems liave been fairly well estab- 

 lished for more than 50 years'. As more de- 

 tailed observations are made of the current 

 systems, however, scientists are increasingly 

 impressed by their ditferences. Recent obser- 

 vations have shown, for example, that the 

 pattern of pennanent ocean currents near the 

 equator in all the oceans is highly complex. 

 The broad equatorial currents flow westward 



Wave Analysis Diagrams 



SouBcE : Wlllard J. Pierson. Jr., et al., Practical Methods 

 for Observing and Forecasting Ocean Waves, U.S. Navy 

 Oceanographlc Office Pub. No. 603, 1955, p. 24. 



in a manner that would be expected as a re- 

 sponse to the westward component of the 

 trade winds on both sides of the equator. But, 

 in addition, an intricate system of powerful 

 countercurrents exists at the surface and at 

 relatively shallow depths below the surface. 

 Although various mathematical models have 

 been proposed to account for these current 

 systems, they are at best only approximate 

 steady state models. An attack on the prob- 

 lem of predicting the fluctuations of major 

 ocean currents will require more detailed 

 data, improved understanding of the air-sea 

 energy exchange, and insight into the effects 

 of bottom topography on ocean movements 

 and of the interrelationships among the cur- 

 rents themselves. 



The Commission recommends that the 

 National Oceanic and Atmospheric 

 Agency take the lead in organizing a series 

 of systematic studies of the ocean's cur- 

 rent systems through cooperative field 

 investigations, employing ship, buoy, and 

 aircraft arrays. 



Sea-Air Interaction 



Research on the interactions between the 

 atmosphere and the oceans is necessary for 

 progress in weather forecasting and in pre- 

 dicting conditions in the upper layers of the 

 ocean. 



A theoretical upper limit for predicting the 

 behavior of individual midlatitude weather 

 details is estimated to be about two weeks in 

 winter and somewhat longer in summer. A 

 rough estimate for the practical limit in the 

 foreseeable future seems to be about one week 

 with an indication that trends could be ex- 

 tended for longer periods. The fluxes of en- 

 ergy, momentum, and water vapor to and 

 from the atmosphere for these time inter\'als 

 (normally neglected for short-range fore- 

 casting) become important. Many aspects of 



