profiles is mild or absent in this region. When it does occur, it tends 

 to be in the depth zone of the warm layer and not in the layer below the 

 thermocline. 



At a distance of 65 miles from the coast, intermediate condi- 

 tions occurred in the sense that the warm layer seemed better able to 

 maintain itself up to and beyond the ice boundary. There was more 

 mesostructure but it did not penetrate below the depth of the original 

 warm layer. 



The milder nature of the phenomena in the region seaward of 

 the coastal current may be ascribed to a much weaker flow of warm 

 water toward the ice. 



IV. GENERAL CONCLUSIONS 



1. The eastern Chukchi Sea, as observed north of 70 N and west to 

 167 W, is influenced by warm water flowing north from Bering Strait. 

 The warm water typically lies in a layer 10-20 m thick atop a cold layer 

 which, in much of the area, appears to be a relic of last winter's 

 freezing processes. The region within 30-50 miles of the Alaskan coast 

 behaves differently than the rest of the area because the water near the 

 coast is flowing rpaidly north-eastward. As a result, the interactions 

 with the ice are more productive of complex temperature and sound- 

 velocity profiles and residues of the warm water intrude farther under 

 the ice than in the region far from shore. 



2. Near the coast, the result of warm water meeting ice is surficial 

 cooling and a formation of a warm nose in the temperature profile, just 

 beneath the surface. Mesoscale temperature inversions and irregulari- 

 ties complicate the profiles both above and below the thermocline. 

 West of the coastal zone similar but less marked phenomena occur. 

 Most of the heat is gone within a few miles under the ice, sometimes 

 even before the ice boundary is reached. Mesostructure generally is 

 mild and is confined to the region near the ice margin and above the 

 thermocline. 



3. The warm layer near the coast gradually descends as it moves to- 

 ward the Arctic Basin. There, at least a portion of the warm water 

 turned east and flows into the Beaufort Sea to at least 147°W. The 

 core of the warm water is at a depth of 25-50 m and is mostly seaward 

 of the 10-fathom curve. In this region it does not interact with ice 

 directly and the mesostructure consequently is mild. The temperature 

 profile typically has a bulge to as much as 4 at the depth of the 

 warm core. 



66 



