46 THE NAVY OCEANOGRAPHIC OPERATIONS PROGRAM 



significantly by dynamic changes in location and characteristics 

 of oceanic water masses — changes that could be traced better with 

 adequate data on currents. At present, however, obtaining 

 accurate current information in deep water is so expensive in 

 time and resources that relatively few measurements are made. In 

 one instance, the Oceanographic Office is installing a complex, 

 moored current meter array in the Bahama Atlantic Undersea 

 Test and Evaluation Center range to help define the dynamic 

 situation there. In another, the Office installed five deep-moored 

 current arrays in "Navy Acre", a one-degree rectangle between 

 Bermuda and Cape Hatteras. Current observations were taken 

 for more than a month for comparison with currents computed 

 from temperature and salinity data. Additional comparisons in 

 the forthcoming interagency cooperative Barbados project in the 

 West Indies will help establish the operational need for deep ocean 

 current observations. 



WAVES 



Wave observations in the past have consisted of random ship 

 reports of visually observed sea conditions. These wave data 

 are not only inaccurate but provide little knowledge of more 

 sophisticated wave characteristics such as spectral components, 

 period of maximum energy, or directional behavior. Wave instru- 

 mentation has now been developed which provides continuous 

 measurement of the sea surface from both ship and aircraft. This 

 wave information is more accurate and infinitely more complete 

 than visual observations. 



The airborne wave meter utilizes a radar altimeter device to 

 acquire an actual profile of the ocean's wave structure. Flying 

 at 500 feet the Anti- Submarine Warfare Environmental Prediction 

 Service aircraft can obtain 1200 NM of wave data, or the equiv- 

 alent of 120 ship reports in 8 hours. Surveys of wave conditions 

 generated by a unidirectional steady wind have produced excellent 

 wave spectra at varying fetch distances and duration times. 



Additional wave data are obtained from a wave sensor installed 

 on ARGUS Island near Bermuda. This installation has permitted 

 the study of storm waves of a height not normally measured by 

 ships at sea. 



