INTRODUCTION 
Investigation of oceanographic phenomena in relatively shallow 
water contiguous to the Continental Shelf seaward of the Virginia 
Capes has frequently shown complex thermal structure inshore of the 
northern edge of the Gulf Stream. Eddies observed by Ichiye (1966, 
1967) in August 1965 and June/July 1966 had major axes of 100 and 20 
kilometers, respectively. Fisher (1969) reported a warm-water in- 
trusion approximately 200 kilometers long in the area during September/ 
October 1967. This feature appeared to extend northward from the Gulf 
Stream in the shape of an inverted "J". Thermohaline characteristics 
of the warm water strongly indicate Gulf Stream origin. A thermal 
gradient coincident with the Continental Slope between Cape Cod and 
Cape Hatteras (Church, 1937; Strack, 1953; and Cresswell, 1967) ef- 
fectively separates Shelf Water from Slope Water. However, the a- 
forementioned investigators disagree as to the period of maximum gradi- 
ent; Church refers to it as a permanent feature, Strack as a permanent 
feature with strongest gradient during summer, and Cresswell as a 
seasonal feature limited to winter months. The presence of these 
features and the Gulf Stream results in rapid spatial and temporal 
change in thermal structure in the survey area. 
A reasonably synoptic study of all phases of the life cycle 
(formation, maturation, and dissipation) of the above features re- 
quires a rapidly moving survey platform. Thus, an aircraft suitably 
equipped for oceanographic survey work was used to observe the area 
seaward of the Virginia Capes throughout a l-year period, supported, 
when possible, by research vessels. This report presents the results 
of flight operations conducted between 9 October 1968 and 16 May 1969 
and a simplified model of oceanic circulation in the area based on 
phenomena thus observed. 
DATA COLLECTION 
Oceanographic phenomena described in this paper are defined 
primarily by sea surface temperature (SST) as measured by an airborne 
radiation thermometer (ART). Measurements were made at an altitude 
of approximately 300 meters and have been corrected for environmental 
effects in accordance with Pickett (1966). The data were averaged 
over 11-minute periods and rounded to the nearest whole degree Celsius 
prior to plotting. 
Subsurface features were examined from the aircraft with airborne 
expendable bathythermograph (AXBT) probes. Recent evaluation of this 
instrument (Bratnick, 1969) indicates a mean difference between the 
AXBT probe and reversing bottles of 0.06°C with a standard deviation 
OrsO SiG 
