Table 1 — Meteorological data averages for the Gulf of Maine region and Xew England coast. De- 

 cember, lOfiT-February lOfiS and December. 196S-February, 1969. * Averages are taken o\er 90 

 day periods (Dec.-Feb.). ** Precipitation values include snowfall. 



Table 1 summarizes precipitation data from 

 the New England Climatological Data Sum- 

 maries (1967 through 1969). It can be seen that 

 total precipitation for New England inland and 

 coastal weather stations in December 1967 and 

 January-February 1968 was not significantly 

 higher than the total precipitation for the same 

 period one year later. 



Shore and inland stations showed northeasterly 

 winds while the offshore light stations recorded 

 northwesterly winds. The latter would thus ex- 

 plain the colder temperatures found in the gulf 

 in 1968. 



Intermediate and Bottom Waters (100 m.efers to 

 hottom) 



A distinct region of cold (<5° C.) mid layer 

 water extending from 100 to 150 meters is gen- 

 erally observed during most of the year in the 

 Gulf of INIaine Basin except during winter months 

 when thorough mixing occurs (Hachey et al.. 

 1954). As expected, no distinct mid layer was 

 observed during the periods of these surveys. 



Mid and bottom waters (150 to 250 meters) in 

 the basin were also found to be approximately 

 l°-2° C. warmer in 1969 than in 1968. In 1968, 

 temperatures of these waters ranged from ap- 

 proximately 4.5°-6.3° C, whereas in 1969, they 

 ranged from 5.5°-8.0° C. 



Transition Zone 



The surface layer waters overlying the shelf 

 edge represent a transition zone between Coastal 

 (Gulf of Maine Basin) and Slope Waters. As 

 can be seen from examinations of the profiles of 



temperature for sections 1, 2. and 3 for ICNAF 

 68-1 (figs. 15, 16, and 17) and for sections 3. 4, 

 and 5 for ICNAF 69-1 (figs. 47, 48, and 49), the 

 temperature gradients in this zone tend to be 

 strong and horizontal. On ICNAF 68-1 a 

 marked increase in temperature from about 5°- 

 10° C. was observed over a horizontal distance 

 (to the south) of approximately 30 nautical 

 miles. This same phenomenon was again ob- 

 served on the 1969 survey, but with temperatures 

 ranging approximately 1.0° C. higher. 



Slope Water 



Slope Water along the east coast of the United 

 States is considered to be a mixture of Gulf 

 Stream and Coastal Waters (McLellan, 1957) 

 (fig. 4). ICNAF cruise 68-1 stations 1, 2, and 

 24-27, and ICNAF cruise 69-1 stations 16-20 

 and 41-46 are considered to lie within the Slope 

 Water region adjacent to the Gulf of Maine 

 Basin. Temperature-Salinity curves constructed 

 from 1968 temperature and salinity data (figs. 6 

 and 8) were shown to be characteristic of Slope 

 Water as determined by McLellan (1957) (fig. 5). 

 However, the warmer temperatures and higher 

 salinity values of the 1969 observations indicated 

 the presence of Gulf Stream water in the region 

 normally occupied by SloiJe Water. Comparison 

 of T-S profiles constructed from the 1969 data 

 (figs. 7 and 8), again with McLellan's T-S rela- 

 tions for Gulf Stream w^ater (fig. 5) further 

 confirmed the intrusion of Gulf Stream water 

 over the slope region. This intrusion is examined 

 further in the forthcoming discussion. 



