INTRODUCTION 



In November 1964, the USCGC MENDOTA 

 (WHEC 69) occupied a line of oceanographic sta- 

 tions from the eastern Grand Banks to the south- 

 east across the main core of the Labrador Current. 

 This was the beginning of the U.S. Coast Guard's 

 "Standard Section" Monitoring Program in the 

 North Atlantic. It has long been recognized that 

 our knowledge of large-scale variations in oceanic 

 circulation, e.g., eddy processes, is very limited. 

 Large-scale problems such as this need a large vol- 

 ume of long-term observations for their solution. 

 In fulfillment of this objective, the U.S. Coast 

 Guard initiated a program to provide for the sys- 

 tematic collection, compilation, and presentation 

 of oceanographic data in the major current sys- 

 tems of the western North Atlantic. Seven sections 

 in the North Atlantic were selected to be monitored 

 by U.S. Coast Guard ocean station vessels; the two 

 oceanographic vessels, the USCGC EVER- 

 GREEN (WAGO 295) and the USCGC ROCK- 

 AWAY (WAGO 377) ; and icebreakers on an 

 opportunity basis. 



The sections were selected to include the most 

 dynamic areas possible and still be somewhat con- 

 sistent with the normal tracks of the ocean station 

 vessels (fig. 1). In most cases, the sections are nor- 

 mal to and include the main axis of a major cur- 

 rent. Sections 1, 2, and 3 extend across the main 

 core of the Labrador Current and occupation of 

 these sections will result in a valuable input for the 

 long-range forecasting of ice conditions on the 

 Grand Banks. During the months of April, May, 

 and June, the USCGC EVERGREEN occupies 

 these sections in direct support of international 

 Ice Patrol research. In fact, section 1 has been 

 occupied nearly annually since 1928 as part of a 

 larger section extending from near South Wolf 

 Island, Labrador, to Cape Farewell, Greenland 

 (Bush, etal., 1957). 



Section 4 extends from the southern Grand 

 Banks southward across the Labrador Current, 

 across the mixed waters of the Labrador Current 

 and into the North Atlantic Current. Data from 

 this section could indicate the boundaries of these 

 currents and their relative strengths in the 

 dynamic area where the Arctic waters of the Lab- 

 rador meet the subtropical waters of the Gulf 

 Stream. 



Sections 5, 6, and 7 encompass the region from 

 Cape Kennedy to the Gulf of Maine and between 

 the continental shelf and the deep offshore waters. 



Data from these sections will provide information 

 in the study of the Florida Current, Gulf Stream 

 and North Atlantic Current systems. 



The utilization of the ocean station vessels which 

 routinely collect oceanographic data at four loca- 

 tions in the North Atlantic, allows a nearly sy- 

 noptic observational program of the Labrador and 

 North Atlantic Current systems. The ultimate goal 

 is a monthly occupation of sections 2 through 5, 

 seasonal occupation of sections 6 and 7, and oc- 

 cupation of section 1 as ice conditions permit. This 

 sampling program was severely curtailed in 

 1965 by the shortage of deep-sea reversing 

 thermometers. 



DATA COLLECTION 



A total of 32 ocean station vessels and the two 

 U.S. Coast Guard Oceanographic vessels, USCGC 

 EVERGREEN and USCGC ROCKAWAY, are 

 equipped to participate in the Standard Section 

 Program. The OSV's occupy a section en route 

 from a particular ocean station, as scheduling per- 

 mits. Each vessel has at least a minimum of the 

 equipment necessary to conduct Nansen bottle 

 casts, make salinity determinations and collect 

 bathymetric and meteorological data. The vessels 

 are now being equipped with the in situ Salinity/ 

 Temperature/Depth Sensor Systems (STD). Ob- 

 servations are made by trained oceanographic 

 technicians who are graduates of the U.S. Coast 

 Guard Training Center's Oceanography School, 

 formerly at Groton, Connecticut. 



The USCGC EVERGREEN was equipped with 

 the STD system in 1966 and made the first success- 

 ful use of the STD system on the Standard Sec- 

 tions on the Gulf Stream-Labrador Current 

 Survey during October-November 1966, which 

 will be discussed later. 



STATION OBSERVATIONS 



1. At the majority of the stations, the maximum 

 sampling depth is 1,500 meters or as near the bot- 

 tom as is practicable if the water depth is less than 

 1,500 meters. In the offshore areas sampling is 

 extended to as close to the bottom as possible at 180 

 to 200 mile intervals. For the 1,500 meter casts, 

 the sampling depths, in general, are 0, 25, 50, 100, 

 150, 200, 300, 400, 500, 600, 800, 1000, 1250 and 

 1,500 meters. Water temperature and salinity are 

 measured at each sampling depth. 



2. Temperatures are measured by deep-sea re- 

 versing thermometers of the Richter and Wiese, 

 Yoshino Keike, and Kessler makes. Two protected 



