86 

 OCEANOGRAPHY 



Edward H. Smith 



It ought to be emphasized that the London convention which gave 

 genesis to the idea of an ice patrol also laid particular stress upon the 

 importance of collecting scientific data. It was believed that the 

 patrol could give the most efficient economic service to shipping only 

 when scientific methods were employed to support the practical 

 work. Oceanographical investigations of the waters of the ice 

 regions have, during the past 13 years of the service, gradually come 

 to be recognized as contributing a clear and accurate insight into the 

 behavior of floating ice. Such information is not only important 

 for the patrol, but it likewise means greater safety for lives and ships 

 on the North Atlantic. It is obvious that observations restricted 

 solely to the surface do not furnish a true and complete picture of 

 the circulation which is in process, and it is only by including the 

 subsurface that we can hope to obtain a correct view of the inter- 

 action between the water masses as a whole. 



The oceanographic information of which the patrol makes a com- 

 plete analysis in arriving at conclusions regarding the behavior of 

 ice, consists of the following: 



(a) Vertical distribution of salinity, temperature, and 

 density. 



(6) Horizontal distribution of salinity, temperature, and 

 density. 



(c) Horizontal distribution of potential (current maps). 



Ice scouting is the primary work of the patrol, and this means 

 limiting the number of stations to the minimum and confining the 

 observations to depths no greater than are essential for obtaining 

 the true picture of the circulation. It is also necessary to remember 

 that the more nearly simultaneous the observations can be, the 

 more accurate picture is for the area covered. An ideal program, of 

 course, includes a maximum number of stations distributed netlike 

 over the area investigated and along lines running at right angles to 

 the currents. Therefore, before commencing the observational work 

 all available data as to the hydrographical nature of the ice regions 

 should be carefully studied. This matter received the attention of 

 the Interdepartmental Board on Ice Patrol as early as 1921, when 

 a tentative program was formulated, which has been carried out 

 more or less intensively ever since. The program was revised slightly 

 in 1926 and is described here in some detail, because observations 

 ought to be patterned along the same general lines for several years 

 to come. A standardized program permits ready comparisons 

 between a series of vears. 



