in 7 instead of 14 days, assuming no delay due 

 to the weather. This was a compromise be- 

 tween adequate sampling of the area and keep- 

 ing the survey as synoptic as possible. He 

 further stated that the temperature and salin- 

 ity changes did not occur gradually but rather 

 abruptly and that the time rate of change was 

 on the order of one to two weeks and perhaps 

 even less. 



Although the Standard Section program 

 was initiated on 14 February 1966 by the CGC 

 DUANE occupation of Standard Section 3 and 

 the CGC HUMBOLDT occupation of both 

 Standard Section 2 and Standard Section 3 

 from 9 to 12 March 1966, Commander, Inter- 

 national Ice Patrol did not start using oceano- 

 graphic information until the first occupations 

 of Standard Sections 4, 3 and 2 by the CGC 

 EVERGREEN in early April, 1966. Because 

 the CGC DUANE and CGC HUMBOLDT oc- 

 cupations provided the only oceanographic data 

 about the Labrador Current ever collected in 

 February and early March, and since the 

 Labrador Current in 1966 was anomalously 

 warm, these two occupations will be discussed 

 here. Vertical sections of temperature and 

 salinity are presented for all 1966 occupations 

 of the Standard Sections. In addition, vertical 

 sections of temperature and salinity are pre- 

 sented for 1954 and 1964, two years that were 

 selected as being representative of normal 

 years. It is hoped that comparison with these 

 vertical sections from "normal" years will 

 emphasize the unusual character of this year. 



Surface dynamic heights along many sec- 

 tions are also presented to underscore the 

 anomalous conditions that were evident this 

 year. This was done to fully utilize the clima- 

 tological mean dynamic height information 

 available in Soule (1964). The dynamic height 

 is the most suitable parameter available to in- 

 dicate net result of the complex temperature 

 and salinity variations that have occurred in a 

 water column. 



CGC DUANE 14-15 FEBRUARY 

 OCCUPATION OF STANDARD SECTION 3 



The discussion of the data collected in 1966 

 begins with the CGC DUANE 14-15 February 

 occupation of Standard Section 3. The surface 

 dynamic height along the section is presented 

 in Figure 6. The vertical distribution of tem- 



perature and salinity is presented in Figures 7 

 and 8 respectively. A chart of the dynamic 

 topography for this occupation is shown in 

 Figure 9. 



Figure 6 indicates that there was a rela- 

 tively strong southerly flow between stations 

 27 and 28 with a relatively flat topography in 

 the east. The Labrador Current is quite ap- 

 parent as the .sharp slope with an average 

 southerly surface velocity of 62 cm/sec. The 

 highest surface velocity in the remaining part 

 of the section is approximately 12 cm/sec be- 

 tween stations 34 and 35. This relatively flat 

 topography to the east was surprising because 

 this section was planned to intersect the North 

 Atlantic Current. Therefore, a strong northly 

 flow was expected on the eastern portion. The 

 North Atlantic Current was not observed, but 

 a mixture of Labrador Current and North 

 Atlantic Current water was found at the 

 easternmost stations. 



The maximum dynamic height value was 

 observed at station 27 and the minimum value 

 occurred at station 30. These maximum and 

 minimum values are the maximum dynamic 

 height of a station to the left of the Labrador 

 Current when looking upstream and the mini- 

 mum value is the dynamic height of a station 

 to the right of the Labrador Current looking 

 upstream. This maximum value may not be the 

 largest dynamic height observed on the section 

 because of the high stands of water found in 

 the North Atlantic Current. The minimum 

 value is generally but not always the lowest 

 dynamic height observed on the section. The 

 maximum and minimum values that will be 

 discussed are associated with the southward 

 flowing Labrador Current. Hence, the mini- 

 mum or trough value may vary in location 

 and magnitude. These values were 971.100 

 and 970.890 dynamic meters respectively. The 

 trough value was 37 nautical miles to the 

 southeast of the maximum value. These maxi- 

 mum and minimum values tended to delineate 

 the region where there was southward flow 

 with Labrador Current water characteristics: 

 temperature of less than 4.0° C and salinity 

 less than 34.9%„. 



The vertical temperature and salinity sec- 

 tions show both the 4.0° C isotherm and the 

 34.0%o isohaline intruding well to the west. 



