D. USE OF ICE POTENTIAL CLIMATOLOGY IN FCHECASTING 



The above discussion of figures 1 through 5 has Implied the use of 

 the techniques of ice potential climatology in ice forecasting. The 

 major point is that siorface ice conditions are related to the physical 

 properties of the surface layer involved in the ice potential calcula- 

 tions. An illustration has been given in the discussion of figure 5 with 

 respect to area H in southern Amundsen Gulf. As long as average ice 

 thickness is the criterion and not the transitory conditions induced 

 by wind movements, the ice potential climatology provides an accurate guide 

 to mean ice conditions. Hovever, the ice potential climatology must be 

 used with the knowledge that the observed ice conditions depend on actual 

 heat loss and not on the postulated constant heat loss. More information 

 needs to be collected as to the heat budget over ice and water in the 

 Arctic. 



While all of the figures are of use in forecasting, the most im- 

 mediate use is seen in figure 5* By subdividing the Beaufort Sea into 

 areas, it is possible to utilize each area as a forecasting indicator. 

 The forecaoter should be aware that conditions in each area ere dif- 

 ferent, and that data from each area are necessary for making a com- 

 plete analysis. As for oceanographic data necessary for calculating 

 the ice potential each year, the delineation into areas as in figure 5 

 makes an effective collection of data much easier, since the number of 

 hjxirogrnj hie stations to be studied can be kept to a minimum. Aerial 

 reconn-iisjance data can be used in conjunction with the ice potential 

 climatology by using areas as indicators . Within such areas as A and F, 

 formation of leads should be common throughout the winter season, while 

 within i5.i-eas B and H, few leads should be noted, and so on for the other 

 areas according to their ice potential and stability. Thus, planning 

 for .rout/3::; to be covered by aerial reconnaissance should include con- 

 sider,? ta on of the areas involved. Similai'ly, the results of aerial 

 reconnoiasancs can be used as verification of the ice potential pat- 

 terns observed in previous oceanographic datas 



It is not the purpose of this report to give detailed rules for 

 ice forecasting by means of ice potential climatology. The aim is to 

 point out some broad categories, of information which are of use in ice 

 forecasting, either on a short-or long-range basis. An example of the 

 former is the use of figure 2 to deduce the relative proportions of 

 winter and polar ice in the various parts of the Beaufort Sea. Figure 2 

 indicates that there may be great differences from place to place in 

 the average age of the ice and the percentages of winter and polar ice. 

 Since flees made up of winter and polar ice have different physical 

 characteristics, they respond differently to environmental factors and 

 hence affect the application of techniques of ice forecasting. 



E. SUMMARY 



Ice potential calculation, which has hitherto been discussed on 

 the basis of individual hydrographic stations, is placed on an areal basis 



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