Oceanography of the Grand Banks Region 



and the Labrador Sea 

 April-June, August and October 1969 



Martin J. Moynihan^ 



and 

 Henry S. Andersen ' = 



INTRODUCTION 



Two oceanographic cruises were conducted 

 by the Coast Guard Oceanographic Unit in the 

 spring of 1969 to the Grand Banks of New- 

 foundland. These cruises provided operational 

 support for the International Ice Patrol pro- 

 gram by describing the physical oceanography 

 of this region affecting the drift and deteriora- 

 tion of icebergs. In addition, an oceanographic 

 section from South Wolf Island, Labrador, to 

 Cape Farewell, Greenland, was occupied in 

 August and October to monitor the variability 

 in the interchange of water between the Lab- 

 rador Sea and the North Atlantic Ocean. 



The first cruise of the 1969 Ice Patrol season 

 was conducted by the CGC CHINTOTEAGUE 

 (WHEC 375) from 2 to 28 April 1969. Ninety- 

 one stations were occupied along the eastern 

 and northeastern slopes of the Grand Banks to 

 complete a survey of the dynamic topography 

 from the Tail of the Banks to Cape Bonavista, 

 Newfoundland. One hundred and thirty-one 

 stations were occupied by the CGC COOK 

 INLET (WHEC 384) during the 14 May to 9 

 June 1969 period of the second cruise. This 

 cruise included a complete survey similar to 

 that on the first cruise and repeat occupations 

 of three standard monitoring sections across 

 the Labrador Current. 



During the period of 15-19 August 1969 

 CGC SHERMAN (WHEC 720) occupied 23 

 stations on the Ice Patrol section across the 

 Labrador Sea from South Wolf Island, Lab- 

 rador, to Cape Farewell, Greenland (fig. 32). 



1. U.S. Coast Guard Oceanographic Unit, Bldg. 159-E, 

 Washington Navy Yard, Washington, D.C. 20390. 



2. Present address: Office of Environmental Affairs, 

 U.S. Department of State, Washington, D.C. 20520. 



These stations were occupied after completion 

 of an Ocean Station BRAVO patrol. The CGC 

 WESTWIND (WAGB 281) occupied 17 sta- 

 tions on this section from 19 to 29 October 

 1969 during the Naval Oceanographic Office 

 annual Eastern Arctic Ice Forecast Survey. 

 This survey was incomplete, however, in that 

 only 17 of a planned 20 stations were occupied. 

 These stations were not synoptic enough for 

 detailed section analysis due to the continuous 

 storm conditions experienced in the Labrador 

 Sea. 

 DATA ACQUISITION AND TREATMENT 



Data were obtained with salinity-tempera- 

 ture-depth (STD) sensor systems on the CGC 

 CHINCOTEAGUE, CGC COOK INLET, and 

 CGC SHERMAN. Temperature data and water 

 samples were collected by Nansen casts during 

 part of the CGC CHINCOTEAGUE's cruise 

 and on the CGC WESTWIND's cruise. The 

 water samples were analyzed on board the 

 vessels with inductive salinometers. The con- 

 ductivity values obtained were converted to 

 salinity by use of the International Ocean- 

 ographic Tables published jointly by UNESCO 

 and the National Institute of Oceanography of 

 Great Britain (1966). 



The STD data were quality controlled by 

 comparison with temperatures and salinities 

 obtained from deep-sea reversing thermometers 

 and water samples collected at the surface and 

 just above the STD sensor at the bottom of the 

 cast. An average quality control correction for 

 each section was determined from the diflfer- 

 ences between the STD data and the associated 

 quality control samples on the individual sta- 

 tions. Corrections were applied to the STD 

 data on a section when the average quality 



