across the deep Bering Sea. 3,6 Fresh water is contributed to the eastern Bering Sea by 

 two large Alaskan rivers, the Kuskokwin and the Yukon. A third large river, the Anadyr 

 in Siberia, also empties into the general region but its effects are felt southwestward 

 along the Siberian coast. In the Chukchi Sea region three rivers flowing into Kotzebue 

 Sound also contribute a large amount of fresh water. Additional details of the geography 

 are brought out in the excellent descriptions of the area by Barnes and Thompson 5 and 

 by Goodman, Lincoln, Thompson, and Zeusler. 6 



water structure 



GENERAL CHARACTER 



Vertical distributions of temperature and salinity in nearly the whole region 

 exhibited a pronounced layering effect typical of coastal systems involving large 

 quantities of run-off. Relatively sharp boundaries separated these layers which in them- 

 selves could be considered virtually uniform with depth (fig. 2). Frequently in horizontal 

 distributions, distinct boundaries also separate water of different characteristics. These 

 geographic distributions will be discussed after first establishing the characteristics of 

 the water masses in the region. 



The temperature-salinity (T-S) relation (correlation of temperature with salinity) 

 was investigated to determine if it could be used to identify the water masses of the 

 region. This procedure has been used frequently in oceanic studies to classify and identify 

 water masses and to trace their movement. It has been used less frequently in coastal 

 or shallow water studies because of the effect of changes at the atmospheric and the 

 coastal boundaries. The temperature and corresponding salinity of each water sample 

 is plotted on a graph using temperature as the ordinate and salinity as the abscissa, as 

 shown for selected stations in figure 8.* These points with the depth indicated are joined 

 by a smooth curve. If the relation is consistent between various stations in shape and 

 location on the diagram, the curve for any individual station can then be used to identify 

 the water mass or masses present. 



The T-S relations in the Bering and Chukchi Seas were consistent. Such consistency 

 in this shallow-water region was maintained because the surface boundary effect was 

 minimized by a constant stratus overcast and high relative humidity during this time of 

 year. At any given station, except those close to the coast, the points for depths above 

 the thermocline were closely grouped, as were those for depths below the thermocline 

 (fig. 8). A wider scatter of points occurs as a result of geographic variation when the 

 points for all the stations are plotted (fig. 2a). Nevertheless, a general grouping of 

 points occurs so that water masses can be identified and the geographic continuity of a 

 given water mass can be followed. 



The water masses used here should not be confused with the deep-sea water- 

 mass classifications of Helland-Hansen 15 and Sverdrup.™ The water masses defined 

 here are purely local and apply only to the shallow Bering and Chukchi Seas and are 

 used as tools to trace the continuity and development of the system. Certain of these 

 masses may be only transient and not even in existence throughout the whole year. 

 They also may vary somewhat from year to year, but the general structure of the system 

 as indicated by these water masses appears consistent with previous data. 5 ' 6,7 ' 8 ' 13 



♦Figures 8 through 13 appear as foldouts at the end of the report. 



16 B. Helland-Hansen "Nogen Hydrografiske Metoder" Skandinaviske Nafurforsker More 1916. 



16 H. U. Sverdrup, ef a/. The Oceans, Their Physics, Chemistry, and General Biology Prentice- 

 Hall, 1942. 



