with greater northern extent than does the O'C isotherm. The -0.5**C 

 isotherm does not define the river plume below 10 meters. No temperature 

 warmer than -Q.11''C was observed at 15 meters although temperature 

 effects from Lena River water were clearly observable as shown in 

 figure 9. 



(2) Salinity Distribution . Observed salinities suggest 



a wedge-like distribution of Lena River water in the Laptev Sea similar 

 to that implied by observed temperature distribution. Interpreted 

 configuration of 15 and 20 %n isohalines, however, indicates a slightly 

 more easterly distribution at depths of 5 and 10 meters than indicated 

 by observed temperatures. 



The 20 %o isohaline variation presented in figure 10 

 illustrates its relative location at the surface and at depths of 

 5 and 10 meters. Relative locations of the 15 o(in isohaline for the 

 same depths are shown for comparative purposes. 



Surface 20 %o isohalines illustrate only the combined 

 effects of the Lena and Khatanga-Anabar River plumes. Surface definition 

 of individual fluvial plumes is limited to salinity values less than 

 15 %o as illustrated in figure 10. The 20%o isohaline extends to 

 yS'OO'N at the surface and at 5 meters and to around 75''20'N at 10 

 meters. At 15 meters, this isohaline existed only near TA'OO'N and 

 132''00'E and did not serve to define the fluvial plume. 



The 15 %(, isohaline does not define the Lena River plume 

 at the surface, but definition may be observed in the 13 %o isohaline 

 configuration seen in figure 5. 



At a depth of 5 meters, the 15 %o isohaline extends to 

 the vicinity of 75"*50'N and defines an elongated region of the same 

 general shape but only approximately half the area defined by the 

 20 %o isohaline. The northern extent of the 15 %o isohaline at 10 

 meters is in the vicinity of TA'SO'N, but the region defined appears 

 primarily in the southernmost Laptev Sea. Below 10 meters, water 

 with salinity less than 15 %o was noted only in a limited region 

 near 74°00'N and 132°00'E. No water with salinity less than 29%n was 

 observed below the 20-meter level in the Laptev Sea. 



(3) River Effluent Distribution . Budinger, Coachman, 



and Barnes (1964) point out that the horizontal distribution of effluent 

 water in the open sea appears to be governed by a combination of 

 offshore circulation and local prevailing winds. Both of these factors 

 probably are effective in governing distribution of effluent water 

 in the Laptev Sea, but their relative Importance is unclear. Because 

 the Laptev Sea is comparatively shallow, surface winds probably assume 

 an important role in distributing this low density water. 



15 



