Ambrose Lightship (Figure 10, ‘Table 10) 
Surface temperatures indicate near "normal" conditions for 
January and February, and early warming beginning in mid-March, with tem- 
peratures above the mean and above the 1956 readings. There was a sharp 
decline during the first 10 days of July, which was accompanied by an 
intrusion of relatively cold water at the bottom. Similar conditions 
were seen in 1956 from Five Fathom Bank as far south as Frying Pan Shoals. 
The intrusion was more pronounced and more extensive in 1957, but as Bun- 
pus has indicated the phenomenon may well be a normal occurrence, pro= 
duced to a greater or less extent each summer by a seasonal change in the 
wind system conducive to upwelling of sorts. (See Chesapeake Lightship 
below) After this intrusion temperatures recovered only to fall off 
again during August. The summer maximum was earlier and cooler than the 
mean and the 1956 record. 
The winter minimum of less than 39°F extended to a depth of 50 
feet; this was ca. 1 degree warmer than the 1956 minimum. The thermo- 
cline started to develop in mid-April with temperatures in the mid-},0's 
and was broken down by the end of October. 
It is probable that both maximum and minimum salinities were 
missed. The pattern, however, is quite similar to that seen in 1956 ex- 
cept that after the spring runoff there is less difference between sure 
face and bottom values than appeared a year earlier. 
23 
