Frying Pan Shoals Lightship (Figure 17, Table 17) 



o 

 Minimum surface temperature of less than 49 F occurred in late February; 



this was 10 lower than the 1956 minimum and 14 below the 1957 minimum. 



Below normal temperatures, surface and bottom, persisted into early June, when 



the thermocline took form. From then on, temperatures remained above the mean 



until late in October, when cooler, fresher water invaded the area briefly. 



The abrupt rise in November, more pronounced than at other stations, reflects 



the warm air temperatures prevailing at that time as well as an advection of 



off-shore water, indicated by a rise in salinity to greater than 36.00 /oo 



In mid-April a depression of temperature and salinity, surface and bottom, 

 no doubt marks an intrusion of coastal water from north of Cape Hatteras. A 

 similar invasion v/as noted in November, 1956. By May bottom salinity had 

 recovered, while surface salinity remained depressed through mid-July. In view 

 of the rapid warming during this period, it is likely that the low surface 

 salinity reflects the offshore movement of local coastal water. 



Inspection of the daily readings of temperature and salinity shows that 

 this region is often subjected to short term and abrupt changes which are 

 obscured in the 10-day mean values of temperature and salinity. 



104 



