PHYSICAL OCEANOGRAPHY OF THE GULF OF MAINE 591 



On August 17, 1912, and again on the 19th, we had readings of 10 to 11.7° as 

 the Grampus sailed lengthwise through the Grand Manan Channel; and it is proba- 

 ble that this is about the highest temperature attained in the tide-swept Lubec 

 Channel, because the highest 10-day average was about 10° there during the last of 

 August and first of September of 1920 (fig. 31). The highest mean temperature 

 recorded at Eastport for a 10-day period for the years 1878 to 1887 was 10.7° (Moore, 

 1898) in the second week of September. 



The surface temperature of the greater part of the open Bay of Fundy likewise 

 ranges from 10° to 12° in August, rising above 12° only exceptionally and locally 

 (Huntsman, 1918; Vachon, 1918). Thus, Mavor (1923) records a range from 9.44° 

 to 12° at 19 stations on thi-ee traverses of the bay inward from Grand Manan on 

 August 22 to 27, 1919, warmest along the New Brunswick shore, coldest (9° to 10°) 

 near Digby Neck on the Nova Scotian side. A similar gradation is described by 

 Dawson (1922) for the first half of August, 1907. The records given by Craigie 

 (1916), Craigie and Chase (1918), and Vachon (1918) for the open bay, with a maxi- 

 mum of 12.68°, a minimum of 8.93°, in July and August, are consistent with this 

 on the whole. 



Dawson (1922, p. 92) records surface temperatures somewhat higher (14.17° to 

 13.33°) than this on a run from Digby to the middle of the bay on the meridian of 

 St. John, New Brunswick (his station A), for July 22, 1907, but this may have been 

 an unusually warm summer in the bay. At any rate, temperatures so high were 

 briefly transitory, for the surface at his outer station had cooled to 13.6° by the next 

 day and to 12.8° three days later (Dawson, 1922, pp. 88-92), when the surface tem- 

 perature along the land from Digby Gut to Brier Island was only 8° to 9°. With a 

 variation from 10° to 11.7° over the Fundy Deep for the three-day period, August 

 23 to 25, 1904, independent of the stage of the tide (Dawson, 1922, p. 95), slight 

 changes evidently are to be expected in the bay from day to day, perhaps governed 

 by the roughness of the sea. 



Many records of temperature, surface and subsurface, have been published for 

 the Passamaquoddy Bay region by Copeland (1912), by Craigie and Chase (1918), 

 and by Vachon (1918), showing a considerable regional variation in the temperature 

 to which the surface attains by the end of the summer. Copeland found the surface 

 warmest (13.9° to 15.6°) in the northern part of the bay, coldest (10.4° to 11°) near 

 Deer Island and in Letite Passage, with the central and western parts of the bay 

 ranging from 11.1° to 15°. Vachon (1918, station 4), likewise records the surface of 

 the center of the bay as warming from 11.4° on July 20 to 15.9° on July 27 in 1916. 

 cooling to 11° on August 3 and 17, but warming again tOjL2.48° on the 25th and 

 to 14.91° on the last day of the month. In the mouth of the St. Croix River, how- 

 ever, the water is kept so thoroughly stirred by the strong tides that Vachon's 

 highest reading was 13.4°, the lowest 10.95°, for the period July 17 to August 31, 

 coolest after northwest winds. Low surface temperatures also rule in Friar Roads 

 between Campobello Island and Eastport, where Vachon reports 8.7° to 10.3° 

 between August 2 and September 17, with 9.5° to 12.62° in the western passage 

 between Deer Island and the coast of Maine, and with about this same range of 

 temperature at a station near St. Andrews. 



