Barnegat Lightship (Figure 12, Table 12) 



The vjinter minimum at Barnegat was 35.4 F during the last 10 days of 

 February; this was some 4.5 F below the mean for the period of record. Vernal 

 warming was slow and lagged behind the mean. Late July and early August were 

 near normal. The sharp depression in temperature in mid-July was seen most 

 strongly at the surface, while temperatures at the bottom showed little 

 change; a similar drop occurred at the same time at Five Fathom Bank, Winter 

 Quarter and Chesapeake stations. At the latter two stations there was chilling 

 at the bottom with indications of upwelling. As in previous years (Bumpus, 1956, 

 and Day, 1957), this appearance of relatively cold water during the summer 

 occurs when a preponderantly south or southwest wind regime becomes established. 

 Such a wind regime drives the warmer surface water offshore; and if the wind 

 pattern persists an intrusion of cold offshore water appears at depth. As 

 this phenomenon was seen each summer since the present observational program 

 was instituted in 1956, and since southwesterly winds are "normal" for the 

 summer months, it is probably safe to assume upwelling of sorts can be 

 expected to occur between Cape Hatteras and New York at some time during the 

 summer. This is essentially what Bumpus surmised two years ago. The 

 extent of chilling through upwelling would depend upon the duration and 

 strength of the southwesterlies in any one year. 



Surface salinity through March was high, close to the 1957 values. 

 Beginning in April salinity declined and remained below the 1956 and 1957 

 readings for the rest of the year. After June bottom samples were taken 

 so infrequently that they are not shown in the running plot. 



58 



