ENVIRONMENTAL 

 FORECASTING PROGRAM 



An important part of the International Decade of Ocean Exploration, 

 and one upon which environmental quality bears, is the Environmental 

 Forecasting program. Oceanographers are well aware that the ocean 

 surface layers are the part of the ocean of immediate human concern. 

 But the remarkable role of the oceans in controlling global weather 

 and climate is not generally understood. 



Uniformly mild surface temperatures do not occur everywhere on 

 earth because of the interference of land masses and of bottom topography 

 upon the circulation of the oceans and the interference of mountain 

 ranges and of continental local heating and cooling upon the circulation 

 of the atmosphere. Extreme effects tend to be smoothed over by the 

 heat-storage capacity of the deep seas. But during much of the last 

 500,000 years the oceans had lost their warm surface layers and the 

 continents had trapped that water on land in enormous ice sheets. Short- 

 term continental interferences upon oceanic regulation of atmospheric 

 circulation are known as weather; long-term changes of oceanic regula- 

 tion of the surface temperature of the planet are known as climate. 



Until recently, the oceanographer has not been faced with the same 

 demands for forecasting that the meteorologist encounters. Formulation 

 of predictive models has to be based on a sound theoretical understanding 

 of the processes at work in the ocean. Because a sound understanding 

 is lacking, it is appropriate to place major emphasis on studies of the 

 surface layers of the ocean and their interaction with the lower atmos- 

 phere, and to determine what dynamic processes are at work in the deep 

 ocean that influence that interaction. 



In the ten years or more since its appearance in oceanography, the 

 digital computer has made it possible to operate detailed descriptive 

 models of oceanic phenomena. On the basis of synthetic data and assump- 

 tions — some to augment the data and others to simplify natural phenomena 

 to make them more tractable or economical in the computer — hypothetical 

 pictures of the oceans now being drawn by the machines closely resemble 

 our present concepts of the oceans. For example, in one analytical model 

 the western boundary currents are properly placed in an idealized ocean 

 basin; in another hypothesis, cold water sinks at the poles and warmed 

 water moves away from the equator. Based on these models, remarkable 

 three-dimensional animated representations of the simulations have been 

 produced by frame-by-frame exposure of motion picture film. Still, many 

 essential details are necessarily lacking; and it must be kept constantly in 

 mind that, although the results agree with our present concepts, it is not 

 certain that the models describe the actual behavior of the oceans. 



