Chesapeake Lightship (Figure 15, Table 15) 



The winter surface minimum, slightly greater than 36 F, occurred in 

 mid-February; it was more than 5 below the mean. At this time there was a 

 vertical gradient in both temperature and salinity, indicating an outward flow 

 at the surface of cold, fresh water from Chesapeake Bay. Minimum bottom 

 temperature did not appear until 3 weeks later. During April warming was 

 rapid and a temperature gradient appeared. The temperature depression at the 

 surface in mid-July and the intrusion of cold, more saline water at the bottom 

 matches conditions seen at stations to the north. The surface maximum of greater 

 than 75 F occurred in August and was followed by cooling in advance of the mean. 

 The hurricane of August 27 and 28 produced northeasterly winds at this station 

 which very nearly destroyed the thermocline; between the 26th and 29th of the 

 month bottom temperatures rose by more than 17 F. As at other stations, 

 chilling was slow during November and rapid in December. 



Three distinct lows in surface salinity appear in February, in early 

 summer and in November. This pattern is similar to that seen in 1956 and the 

 values are comparable. The 1957 surface salinities after April were markedly 

 higher, except during late December. 



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