estuaries, and barrier islands), and to support limited research on 

 boundary-layer physics and oceanography directly related to 

 tropical-storm surge prediction. 



Major Research Projects 



The past year has seen considerable progress in a number of 

 interdisciplinary projects involving numerous Federal agencies, 

 and, in some instances, multinational planning and coordination. For 

 example, detailed understanding of the kinetic and potential energy 

 and the movement of large bodies of w^ater in the oceans is critical to 

 the development of ocean-circulation models, which are fundamen- 

 tal to improved environmental prediction. The Mid-Ocean Dynamics 

 Experiment (MODE), a joint project of NSF and the Naval Research 

 Laboratory (NRL), has sought to describe one important feature of 

 ocean circulation, medium-scale eddies. Participants from 18 

 academic institutions completed a 4-month field experiment in July 

 1973, using six ships and extensive instrumentation at a site 400 

 miles southwest of Bermuda. Data obtained during the 4-month field 

 experiment have made it possible to describe and map one of these 

 eddies. 



The POLYMODE^ experiment, which is being planned, organized, 

 and conducted jointly by U.S. and Soviet scientists, will seek to 

 understand the energy source and number of medium-scale eddies. A 

 comparison of the MODE-1 area and the proposed POLYMODE site 

 began in mid-1974 and will continue until the start of an intensive 

 field program scheduled for 1977. Understanding these eddies is 

 fundamental to the development of a physically correct ocean- 

 circulation model. Such a model will provide a basis for both short- 

 range and long-range ocean forecasting and will fit into general 

 models linking the behavior of the atmosphere and oceans. 



The main scientific objectives of POLYMODE are 



(1) To conduct a kinematic and descriptive study of the midocean 

 eddy field, including eddy-eddy interactions, on significantly longer 

 time and larger space scales than previously studied 



(2) To determine local dynamic balances in a typical midocean 

 region 



(3) To determine the contributions to eddy transport of momen- 

 tum, heat, and energy, and their meridional distributions, as well as 

 the interaction of eddies with the mean circulation 



' POLYMODE is the shortened foriri'of the combined Soviet POLYGON experiment 

 and U.S. MODE-I effort, both of which seek to identify the features of medium-scale 

 eddies. 



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