dynamics of wind-wave growth. During Hurricane Ava in June 1973 

 the first aircraft measurements of wave conditions in a hurricane 

 were made to determine the role wind waves play in the behavior of 

 these storms. These data are being correlated with Skylab 

 measurements taken at the same time. 



Acoustic echo sounders are being used by the Atlantic Laboratory 

 to measure the amplitude, speed, and direction of internal waves to 

 determine the role internal waves play in the overall dynamics of the 

 sea. NOAA's Pacific Marine Environmental Laboratory is 

 investigating the generation of internal waves by surface tides as 

 they impinge on a continental shelf. Experiments have shown that 

 semidiurnal internal waves are propagated seaward from the 

 continental terrace as the tide moves across it. Successive studies 

 are attempting to quantify the energy content and distribution of 

 these internal waves. 



NOAA and the University of Hawaii have developed a cooperative 

 research program to increase our understanding of the generation, 

 propagation, and onshore runup mechanisms of tsunamis. The first 

 station of a 10-station network of open ocean tsunami measuring 

 instruments has been deployed on the sea bottom under a North 

 Pacific weather ship. This device will, for the first time, measure 

 tsunamis in the open ocean and provide earlier and more accurate 

 tsunami forecasts. 



The transient and rapidly changing features of ocean circulation 

 are proving amenable to study with airborne and satellite remote 

 sensing techniques. For example, the Navy uses its oceanographic 

 aircraft to investigate characteristics and life cycles of eddies 

 spawned by the Gulf Stream and frontal systems in the western 

 North Atlantic. It also uses a Data Acquisition and Processing 

 satellite to determine the thermal resolution of the Gulf Stream and 

 to identify water mass boundaries. Moreover, software has been 

 developed to produce charts of surface thermal patterns in real time 

 from satellite infrared imagery. 



The Mid-Ocean Dynamics Experiment (MODE), a coordinated 

 oceanographic project supported jointly by the NSF/IDOE andONR 

 is designed to establish a dynamically correct model of oceanic 

 circulation. A major field experiment took place from March to July 

 1973 involving 30 scientists from 18 institutions in an area midway 

 between Bermuda and the Bahamas. Investigators identified eddies 

 with a 100-kilometer diameter that extend from the bottom of the 

 ocean up to the lower boundary of the mixed layer, typically at a 

 depth of 100 meters. They even observed the growth, dispersion, and 

 decay of an eddy. 



In another cooperative project, NSF joined with AEG to support a 

 1972 study of a deep ocean boundary current in the Atlantic, off the 



98 



