94 



INTERACTIONS OF ICE AND BOUNDING MEDIA 



Ice reacts in various ways across its interfaces with sea, air and land. 

 The sea and air in particular affect the formation, movement and disintegration 

 of ice. Ice affects the temperature and salinity of the water, the temperature 

 of the air and the transport of energy and mass from sea to air. It gives an ef- 

 fective wintertime extension of continental limits with attendant effects on local 

 marine weather. It reduces wave motion in the sea on the one hand and, as it 

 retains fresh water in freezing, sets up convective currents within the sea, on 

 the other. Ice erodes beaches and shallow bottom areas and transports terri- 

 genous materials far seaward. Characteristic fauna and flora are associated 

 with sea ice areas. 



Numerous studies are being made of the interrelationships between ice 

 and its environment. Our knowledge, however, of properties and processes is 

 still too meager to make valid, long range predictions of ice conditions. These 

 have been tried for both icebergs and pack ice. Even short range predictions 

 must be, in general, qualified. Existing gaps can be narrowed by reconnais- 

 sance and climatic type studies, investigations in situ of the intimate proper- 

 ties and processes of ice itself, and laboratory experiments under controlled 

 conditions. With increased intensity of effort, the instrument ceiling may be 

 reached sooner than anticipated. Efforts should be made first to adapt the best 

 of appropriate present day instrumentation to sea ice studies, and next to devel- 

 op new instrumentation as needs are indicated. It is suggested that this be done 

 by increasing the over-all effort devoted to sea ice studies and not by shift of 

 emphasis within the present group of investigators. 



CONCLUSIONS # 



1. Conventional oceanographic and related instruments can, in general, 

 be used for sea ice studies with but little modification. Much new 

 information can be gained from their use. 



2. Instrument design should be keyed to the facility, ship, plane or sub- 

 marine affording contact with the ice, as well as to the problem 

 being studied. 



3. Studies of sea ice are not progressing at an optimum rate. Inade- 

 quate facilities for contact with ice, failure to use present facilities 

 to their fullest extent, an insufficient number of participating scien- 

 tific personnel, and lack of formal instruction and training in the 

 field are factors to be considered. 



DISCUSSION: Waldo K. Lyon 



My remarks are only an echo to those of Clifford Barnes. Sea ice is a 

 transient boundary state of the sea; a complex of discontinuities much in con- 

 trast to the normal continuum of the oceans. The meagerness of our knowledge 

 makes discussion difficult. We cannot write down an expression which will de- 

 scribe the chemical or physical structure of sea ice, though such structural 

 complexes as glasses, ceramics, rubbers, etc. can be described. 



Inspection Phase - As with every problem, the first approach is the descrip- 

 tive exploration stage -- the inspection phase. Historically, the seas having 

 perpetual sea ice were the last to be explored, and consumed the major explora- 

 tion effort done during the last century. The exploration phase has carried 

 well over into the first part of this century, but during the past thirty years 

 we have seen the transition to the second phase, that of quantitative measure- 

 ment. If a starting point be named, it is likely H. U. Sverdrup and the Maud 



