adverse sea conditions prevented taking Nansen stations. Thirty- 

 one SXBT and 16 Nansen stations were taken during Phase II. The 

 SXBT probe has a temperature accuracy of +0,2*'C and a depth accu- 

 racy of +4,6 meters or 2 percent (whichever is greater). 



Meteorological data recorded every 6 hours and SST data 

 recorded daily by Coast Guard personnel at Chesapeake Light Station 

 (36<'58.7*N,75°42.2'W) are used to describe prevailing weather in 

 the survey area. SST data collected by the Environmental Science 

 Services Administration are used to describe water temperature in 

 Chesapeake Bay. 



DATA ANALYSIS 



SST patterns observed by ART on 24, 25, and 26 February and on 

 8 March are shown in figures 3 through 6. Corrected ART values were 

 averaged over one-minute periods for plotting. Analysis of the data 

 shows (1) highest SST in deepwater areas and lowest in shallcw-water 

 areas, (2) isotherm orientation generally parallel to the coastline, 

 and (3) an area of warm water in the southeastern quadrant of the 

 survey area. 



The temperature patterns (figures 3-6) between the warm and cold 

 water were too complex to show the exact ccm figuration of the boundary. 

 Several exairples of the frontal zone at the boundary are presented in 

 figure 7. 



Changes in the SST pattern were computed for two survey periods. 

 Figure 8 shows the temperature change between 24 and 26 February. 

 Figure 9 shows the temperature change between the last flight of Phase 

 I (26 February) and the only flight of Phase II (8 March). Tempera- 

 ture change in the southeastern quadrant of the survey area and in the 

 region extending seaward from the coast between Cape Henry and False 

 Cape is the most predominant feature of the analyses. 



Because Nansen casts taken during Phase II are representative of 

 water conditions throughout the survey, the vertical water structure 

 is described only with Nansen cast data. Each station was repeated 

 at a time interval varying from 19 to 42 hours. Temperature, salinity, 

 sigma-t, and sound velocity profiles shown in figure 10 for station 7 

 (36°50'N, 75°00'W) are representative of the profiles at the other sta- 

 tions. The time interval between the initial occupation and reoccu- 

 pation of Station 7 was 22.5 hours. The T-S diagrams for Station 7 

 are shown in figure 11. 



A combination of a high-pressure system over the eastern United 

 States and a low over the Canadian Maritime Provinces caused gale 

 winds and subfreezing temperatures in the survey area during Phase I. 

 The high, which moved over the Carolinas on 27 February, was followed 



