PREFACE 



This study concerns the distribution of spa ice and ice of land 

 origin in the Baffin Bay-Davis Strait region. Consideration is given 

 to ice as it normally appears in these areas in terms of space and time. 

 It should be emphasized, however, that the presentation of sea ice condi- 

 tions for any given period of the year, although substantially useful as 

 a guide, may have restricted value when applied to a specific field oper- 

 ation. 



In order for a study of this nature to be applicable to a specific 

 operation, a broad scale investigation of the dynamic as well as th» kine- 

 matic forces involved in the processes of sea ice formation, growth, de- 

 velopment, and distribution would be required. A well integrated approach 

 to the problem would include the determination of the thermohaline structure 

 of the waters (on a much larger seal" than heretofore employed by this 

 Office), and a continuous study of air temperatures, wind, and precipitation. 

 This would establish not only the date of initial ice formation, but also 

 its rate of growth. The second step in the field investigation of ice 

 would include long-range aerial surveys of the ice throughout the area 

 of distribution for visual evaluations of the many topographic features 

 of the ice, significant ice forms, extent and concentration of the ice, 

 the location of certain types of sea and land ice, and its designation 

 in terms of textual and graphic presentation. This type of study of sea 

 ice conditions would furnish reliable data. It wotild provide the location 

 of sea ice suitable for forced or deliberate landing of aircraft and infor- 

 mation consonant with the requirements of any specific operation. 



The formation and growth of sea ice is a function of oceanographic and 

 meteorological variables. These vary from year to year, so we may expect 

 different ice years. The distribution of ice over a given water area, with 

 respect to variance in topographical features, is also a function of the 

 meteorological parameters. Thus, th > magnitude and frequency distribution 

 of pressure ridges, the number and quality of refrozen leads, and the pres- 

 ence or absence of open water areas are related and are subjected to the 

 impact of the pressures and stresses exerted on the ice by the passage of 

 many storms and pressure patterns of varying intensities. If the early 

 history of development and growth of winter ice is associated with rela- 

 tively long periods of calms, light winds, and few storms, the topography 

 of the ice wiU feature few pressure ridges. Conversely, if the early- 

 history is associated with intense storm activity, the topography of the 

 ice will present a wild array of pressure ridges, compressed and irregular 

 ice, and a high degree of rafting. V.'ith respect to the latter, however, 

 there are greater number 9 of frozen leads in varying stages of growth, size, 

 and orientation. 



The presentation of normal sea ice conditions, in the Baffin Bay-Davis 

 Strait region, is based largely upon the observations of personnel of the 

 U. S. Navy Hydrographic Office. Over the past years, they have flown several 

 hundred aerial ice reconnaissance surveys, either preliminary to, or in 



