2 76 POLAR PROBLEMS 



denskjold, and R. C. Mossman from Weddell Sea, by H. Arctowski 

 from the Belgica drift in the southeastern Pacific, and by C. S. Wright^* 

 and L. Kohl and Sten Valhn from Ross Sea. The variations in saHnity 

 and temperature occurring among these observations are shght and 

 seem to have been caused by the different forms of the shelf sea 

 bottom. 



This typical "polar water" of the shelf seas, as I should like to call 

 it, is caught by currents and carried northward. It is to be found in 

 the drift-ice belt and in the west-wind drift northwards to the 50th 

 parallel of south latitude close to or immediately below the surface 

 (Fig. i). Above it lies, frequently in the drift-ice belt but rarely in the 

 west- wind drift, a layer of water which is generally very thin but whose 

 salinity and temperature vary greatly. Both circumstances are due 

 to the disintegration of the drifting floes and icebergs, so that this 

 layer may properly be termed "ice-melted water." This water is 

 differentiated by its fluctuating characteristics from the polar water 

 underneath, with its constant characteristics. During the Gauss 

 expedition the polar water in the southern Indian Ocean had a thick- 

 ness of 100 to 300 meters and rested with an undulating contact surface 

 on the tropical or intermediate water below. North of latitude 

 50° S. the polar water submerges and then flows at a depth of about 

 1000 meters to beyond the equator. The Gauss expedition was able 

 to observe its distribution in the Indian Ocean to the Tropic of Capri- 

 corn and in the Atlantic to the Tropic of Cancer, the latter observa- 

 tions having also been made by the Deutschland expedition. It forms 

 an important horizon for the subdivision of the deep sea, as its tem- 

 perature increases northwards only gradually and slowly and its 

 salinity changes very little. For the Pacific region no corresponding 

 observations are yet available. 



Westward- Flowing Current Along the 

 Antarctic Continent 



Movement is imparted to the current of polar water, and to the 

 melted water above it, by the wind; its direction is determined by 

 the wind, by the earth's rotation, by the coasts, and by the border of 

 the shelf ice. At the Gauss station we were able to recognize a purely 

 superficial drift, caused by the wind, which flowed to the south and 

 consequently toward the coast, as a result namely of the deflection 

 of the east-west wind direction to the left.^^ Below this surface drift 

 we found a gradient current [Windstaustrom] in the sense of V. W. 



'* C. S. Wright: The Ross Barrier and the Mechanism of Ice Movement, Geogr. Journ., Vol. 

 65, 1925, pp. 198-220; reference on p. 219. 



15 Drygalslci, Ozean und Antarlctis, pp. 512 ff. 



K. Hessen: Gezeiten- und Strombeobachtungen auf der Winterstation des "GauSs" 1902-03 

 (Deutsche Siidpolar Expedition 1901-1903, herausg. von Erich von Drygalsici, Vol. 7, Part V. pp. 

 557-602), Berlin and Leipzig, 1926, pp. 587 ff. 



