Ambrose Lightship (Figure 10, Table 10) 



The winter minimum, more than 2 F below the mean, occurred in late 



o 

 February with a temperature of 35.6 F. Recovery had been made by April, at 



which time the thermocline started to develop. There are no data for May 



and part of June when the vessel was off station, but the record resumes 



showing a cold summer ijith early cooling and temperatures well below the 



mean. The summer maximum of 71.4 F occurred in early August. The passage 



of hurrican Helene on 28 September weakened the thermocline by mixing, 



but the gradient was not completely destroyed until the last decade in 



October. At this time bottom temperature reached a maximum of 57.5 F. 



Above normal air temperatures in November retard cooling. In December the 



vessel was again off station. 



Salinities at the surface were similar to those of 195G except that the 

 minimum of 24.65 /oo was considerably lower. The 1957 values were uniformly 

 above those for 1956 and 1958. 



5 50 - 



SURFACE T.'F 



J I i I I \ I I I 



BOTTOM SX. 



SURFACE S*. 



Figure 10. Ambrose Lightship, 1958. (Dashed line in upper diagram, mean 

 for period 1937-1956) 



49 



