Oceanography of the Grand Banks of Newfoundland in 1965 



by 

 Ronald C. Kollmeyer, U.S. Coast Guard 



Introduction 



The Ice Patrol surveys during 1965 were con- 

 ducted in a son^e^^■hat different manner from the 

 standard sampHng routine of the past. A new 

 oceanographic station array was established 

 paralleling the old standard surveys in some areas 

 and diifering considerably in others. Figure lA 

 shows the old trackline of the southern survey and 

 the new trackline used in 1965. The purpose of 

 revisuig the trackline was to reach a compromise 

 between adequate sampling of the area while 

 keeping the survey as synoptic as possible. The 

 new station array included 62 stations compared 

 to 97 stations of the previous method and allowed 

 completion in 7 days in lieu of 14 days. 



The standard sections of previt)us years have 

 retained their designations in the new station array 

 despite their relocation. Their new positions are 

 not significantly different and allow comparison 

 with historical Ice Patrol data. Figure lA shows 

 the section designations under the new and the 

 old station arrays. 



The standard treatment has been given the 

 data as in past years with the exception of the 

 volume and heat flow comparison for the standard 

 sections. Annual volume and heat flow com- 

 parisons lose their significance imless adjusted 

 for time. They are virtually meaningless unless 

 compared to flow buildups and declines irrespective 

 of the specific calendar survey dates. Past data 

 indicates the major buildup and decline in the 

 \-ohune flow of the Labrador Current can occur 

 anytime during the spring. This requires that 

 the data must be adjusted in time by volume 

 flow maximums in order to make comparisons on 

 an annual basis. It will be shown hi the following 

 sections that monthly surveys will not provide the 

 information required to define the accelerations of 

 this system. Past data analysis techniques have 

 not even shown the volume flow trends which 

 would allow an annual time matching of the flow 

 peak or peaks. 



The sampling of the water mass was accom- 

 plished by first conducting an electronic bathy- 

 thermograph lowering to 410 meters at each 

 station. Nansen bottles were then hung at levels 

 that would obtain temperature and salinity data 

 wliich would best describe the water column. The 

 merits, results, and comparisons of this technique 

 are examined in a following paper. 



Some methods of presentation, new to Ice 

 Patrol, have been attempted in an effort to analyze 

 the data more effectively. Ultimately, they may 

 lead to an understandmg of the cuTulation m the 

 area which will allow formulation of better 

 samplmg techniques and possible prediction of 

 current changes necessary for the solution of the 

 berg tracking problem . 



NARRATIVE 



General 



Three oceanographic cruises were conducted by 

 USCG cutter Even/reen, a 180-foot tender class 

 oceanographic vessel, in support of the Interna- 

 tional Ice Patrol during the spring and summer 

 of 1965. A summary of the location and extent 

 of each cruise follows. 



The first cruise began on 30 March 1965, with 

 the occupation of Evergreen Station 9235 on the 

 southwestern slope of the Tail-of-the-Banks and 

 proceeded northward with serial stations ter- 

 minating at station 9296 on the Grand Banks 

 west of Flemish Cap on 7 April 1965. This cruise 

 was designed to delineate the three principle water 

 types in the area, namely, the Labrador Current 

 Water, Mixed Water, and Atlantic Current Water, 

 and to provide, within 12 hours of observation, 

 vertical temperature distribution and dynamic 

 heiglit at each station to commander, Interna- 

 tional Ice Patrol. Serial stations 9253 through 

 9260 were reoccupied as stations 929S through 



