factors, qualitative relationships should be sought in this area for the 

 present. As northern ice survey data are accumulated and correlated 

 with weather and other factors, quantitative relationships may even- 

 tually be developed. Daily forecasting of ice conditions during the 

 period between observed ice conditions depends on the accuracy of 

 the observed ice conditions and the forces acting on the ice between 

 observations. One of the main forces affecting the drift and deteriora- 

 tion of ice is the wind. A quantitative relationship must be developed 

 for the drift of icebergs of various sizes and shapes due to wind. 

 Naturally, oceanographic factors must be taken into account. While 

 the weather is most important in determining the amount of bergs 

 that reach the Tail of the Banks, once in the swift moving Gulf 

 Current, oceanographic factors are by far the predominant force 

 acting on the bergs. 



Long range forecasting may not be as urgently required as the twice 

 daily forecasting of bergs in or near the shipping lanes, but it must 

 be pursued if real meaningful progress is to be made on the latter. 

 Simply stated, the more we can learn about icebergs and all the factors 

 that influence them, the greater our capability to accurately forecast 

 what will happen to them. We can develop long range forecasting 

 ability by correlating observed ice conditions with known factors and 

 hindcasting. True, the unavailability of reliable weather forecasts 

 1 month or even 1 week in advance is a serious handicap. The fore- 

 casts can be made assuming normal weather and both extremes. All 

 the factors that cause and influence the Grand Banks iceberg problem 

 can be classified into two basic groups, meteorological and ocean- 

 ographic, both groups being highly interrelated. The basic meteoro- 

 logical factors are surface winds, air temperature and precipitation. 

 The basic oceanographic factors are current, water temperature, sea 

 ice, and bottom topography. The plan of approach is to make use 

 of pertinent measurable factors and correlate with resulting ice con- 

 ditions, while accounting for all other factors as practicable. 



Hopefully a capability will be developed to forecast the severity of 

 the ice season before it begins, and to make fairly accurate weekly and 

 monthly forecasts of ice conditions on the Grand Banks. Forecasts 

 made during the ice season can take into account a relatively abundant 

 store of oceanographic data available. Preseason forecasts must de- 

 pend mainly on meteorological elements, as oceanographic factors are 

 for the most part, unobtainable during winter months in northern 

 areas. There is consolation in the fact that, except for bottom topog- 

 raphy, the oceanographic factors and changes therein will be largely 

 accounted for by the meteorological elements to be considered and can 

 reasonably be assumed. While tlie interactions between the atmos- 

 phere and the oceans are quite complex and not well understood, it is 

 known that abnormal atmospheric pressure patterns will effect changes 



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