ABSTRACT 



The authority for, mission, forces assigned and method of 

 operation of the International Ice Patrol during the 1956 ice 

 season are described. 



Aerial ice observation and communications statistics are 

 presented. 



All ice reports made to the International Ice Patrol in 1956 

 are tabulated. A general month-by-month description of ice con- 

 ditions in the Newfoundland area is given. Only 80 bergs drifted 

 south of latitude 48°N during the year, a low figure in comparison 

 with the 1900-1956 average, 391 bergs. The most southerly berg 

 of the season was reported 28 May in 44°58'N., 49°22'W. The 

 duration and maximum extension of the pack ice to the south and 

 east of the Newfoundland coast were subnormal. 



The three dynamic topographic charts resulting from the 

 season's current surveys have been discussed. 



A more detailed analysis of the Labrador Current has been 

 made based on the velocity profiles at 18 selected sections occu- 

 pied during the 1956 season and post season cruises. 



Mean curves representing the T-S relationship for Labrador 

 Current water, mixed water and Atlantic Current water have 

 been derived for the period 1948-56 and compared with similar 

 curves for the period 1934-41 and the conditions found during 

 1956 have been compared with the means. 



Tentative normal seasonal variation relationships have been 

 presented for the volume transport, mean temperature and mini- 

 mum observed temperature of the Labrador Current at sections 

 F and G, located near the northeastern shoulder of the Grand 

 Banks. 



The temperature and salinity of the intermediate water of the 

 Labrador Sea have been examined for each of the 16 occupations 

 of the South Wolf Island-Cape Farewell section since 1934. While 

 year to year variations have been large the average temperature 

 for the period 1948-56 was the same as for the period 1934-41 

 but the salinity has been lower in the later period. 



Examination of the deep water of the Labrador Sea for the 

 same periods showed a slight warming and freshening at 2000 

 meters, an isothermal freshening at 2500 meters and a freshen- 

 ing accompanied by a cooling at 3000 meters. The combined 

 effects result in about the same decrease in density at each level. 



(v) 



