IV. OCEANOGRAPHY 

 A. The Laptev Sea. 



The temperature and salinity distribution observed in the Laptev 

 Sea in 1963 revealed a high degree of stratification at the time 

 of the survey. Temperatures generally were observed to increase 

 toward the Siberian coast and vertically from the bottom, and salinities 

 were observed to decrease toward the coast and vertically from the 

 bottom. Figures 5 through 8 show horizontal temperature and salinity 

 distribution in the upper 15 meters as observed in August and September 

 1963. 



1. Temperature-Salinity Relationships . Water of two very general 

 types was observed in the Laptev Sea during the NORTHWIND survey. 

 Below 20 meters on most stations, temperatures and salinities were 

 observed to be similar to surface water found in the Arctic Basin. 

 In addition, on some of the northernmost stations, water with the 

 same characteristics was observed throughout the water column. Water 

 with temperatures and salinities similar to those found at the surface 

 in the Arctic Basin will be referred to here as "Arctic Basin Surface 

 Water". Temperatures of 1.4° to -1.8°C and salinities greater than 

 28 "^(lo are characteristic of Arctic Basin Surface Water. 



In the upper 15 meters at the remaining stations, temperatures 

 were observed to be considerably higher and salinities considerably 

 lower than those of Arctic Basin Surface Water. This high temperature, 

 low salinity water will be referred to here as "Southern Laptev Water" 

 as it originates in the southern Laptev Sea. 



a. Arctic Basin Surface Water . It is reasonable that water 

 in the northern Laptev Sea should have temperature and salinity characteristics 

 similar to those in the surface waters of the Arctic Basin. Coachman 

 and Barnes (1962) describe Eurasian Arctic Basin Water as being cold 

 and relatively dilute in the upper 25 meters, with salinities ranging 

 from 28.5 to 33.5 %o and temperatures always less than O^C. Below 

 25 meters, the temperature is described as being at or near freezing 

 and isothermal down to 50 or 100 meters, with an accompanying marked 

 Increase in salinity. 



Temperatures observed in the northern Laptev Sea in 1963 

 ranged from less than -1.5°C at the surface to -1.8'C at 50 meters. 

 Salinities ranged from 28.6 %o at the surface to 33.9 %o at 50 meters. 

 Since these values fall within the range described by Coachman and 

 Barnes, the water can be considered to represent Arctic Basin Surface 

 Water. This water also was observed at 20 meters and below on most 

 other stations, with temperatures generally less than -l.O'C and 

 salinities generally greater than 28 %o . 



