60 



MARION EXPEDITION TO DAVIS STRAIT AND BAFFIN BAY 



thus to avoid any liability to bias. The correlation between the ' 

 winter atmospheric oradient, Ivi<itut to Belle Isle, and the spring ' 

 crop of pack ice south of Newfoundland was found to be +0.86. 

 (See pp. 180-189.) 



Brooks and Quennell (1928, p. 33) besides investijjatin^^ the effect 

 of Arctic and Greenland Sea ice on European weather also studied ■ 

 the effect of varying masses of pack ice and cold water introduced 

 off Newfoundland. They found : 



1. Much pack ice off Newfoundland in the sprin^r. April to June, 

 tends to occur with low atmospheric pressure for the same period at 

 Iceland and hio;]i pressure at the Azores. 



2. Much pack ice off Newfoundland in the sprino- tends to be fol- 

 lowed nine months later by high pressure over northern Norway and 

 low pressure over southern England. ' 



3. Much pack ice off Newfoundland in the spring tends to be fol- 

 lowed 15 months later by high ])ressure at the same places as (2). 



Finally, the effect of ice off Newfoundland on the pressure over i- 

 western Europe is generally similar to that of the polar cap ice and ' 

 of the (ireenland Sea pack, but as might be supposed, is much less 

 pronounced. The correlation coefficients between ice off Newfound- 



Pack-Ice Graph for the Western North Atlantic 



Figure 30. — A graph representing the rehitive fimouuts of pack ice south of New- 

 foundlauci by years, 1880-1927. The data upon which this graph is based was 

 taken from Mecking (1906) for the years 1880-1900. and since then from the 

 records and the researches of the international ice patrol. 



land, April to June, and pressures at Vardo, Valencia, and Berlin, 

 June to March, of 30, 20, and 31, respectively, are not high, yet may 

 have some small value for forecasting European weather. 



LAND ICE 



Glacier ice, formed from precipitation on land, is of great impor- 

 tance as the source of icebergs. Under the present distribution of 

 temperature and snowfall over the earth, the permanently ice- 

 decked lands lie mostly within the polar regions. The greatest single 

 ice sheet in the Nortliern Hemisphere is that which overlies (ireen- 

 land, in area equal to all lands east of the Mississippi River and south 

 of the St. Lawrence River. Greenland is the ])rincipal source of tlio 

 icebergs that are found drifting in the North Athintic ami in its 

 tributary seas. 



The treatment of icebergs must necessarily include their general 

 distribution in time and i)lace. their form, size, color, markings, 

 volumes of flotation, manner of disintegraticm. etc.. all dependintj to 

 a great degree upon conditions which existed long before the ice- | 

 berg was l)orn. Chamberlin. Drygalski. Koch. Priestley, de Qiier- j 

 vaiu. llobbs. iiud uiauv otlici-s have carried out notable observations 



