WEBSEC Projects of Opportunity 



By 



Gary L. Hufford^ 



INTRODUCTION 



The U.S. Coast Guard Oceanographic Unit has 

 Deen coordinating a summer and early autumn 

 muhidisciplinary marine ecological baseline in- 

 k'estigation (WEBSEC) of the coastal waters adja- 

 :;ent to the Alaskan North Slope since 1970. Some 

 )f the shortcomings of the cruises was: (1) lack of 

 )ther seasonal data; and (2) determination of the 

 ource of a warm water advection in the western 

 Beaufort Sea. Opportunity arose to conduct short 

 arograms from the USCGC GLACIER in 1971 

 ind the USCGC STATEN ISLAND in 1972 to 

 lelp solve some of the shortcomings of WEBSEC. 



An expendable bathythermograph (XBT) pro- 

 gram was conducted aboard the CGC GLACIER 

 rom the Bering Strait to Point Barrow, Alaska to 

 trace Bering Sea water to the western geographi- 

 cal boundary of the Beaufort Sea. It was hoped 

 that the data might substantiate the hypothesis 

 that the warm water mass observed in the western 

 Beaufort Sea is in fact Bering Sea water. This 

 report contains the results of these XBT sections 

 taken in mid-August and in mid-September, 

 1971. 



Oceanographic stations of opportunity were 

 taken along the North Slope from the CGC STA- 

 LEN ISLAND during early July, 1972. This re- 

 port contains the physical and chemical data col- 

 lected on this cruise and a preliminary discussion 

 af the results. 



EASTERN CHUKCHI SEA 



In the summer near the North American conti- 

 lent, the coastal waters of the eastern Chukchi 



U.S. Coast Guard Oceanographic Unit, Washington, D.C. 20390. 



Sea are characterized by a warm (>2°C), low 

 salinity ( <3 l7oo) water that has flowed north from 

 the Bering Sea. This water has been classified 

 Alaskan Coastal Water (ACW) by Saur et al. 

 (1954). It is known to occupy the entire water 

 column near the continent. The low salinity of the 

 water mass reflects the large freshwater discharge 

 of the Alaskan Rivers into the Bering Sea. As one 

 proceeds away from the coast to the west, the 

 depth of the ACW becomes less than 25 meters. 

 Below the warm layer an intermediate water mass 

 is found and is characterized by temperatures of 

 more than 2°C and salinities of 30.6 to 32.27oo. 

 Origin of this water mass is also the Bering Sea. In 

 the central portions of the eastern Chukchi Sea, 

 the surface waters are influenced by warm Bering 

 Sea water and by local heating (Aagaard, 1964). 

 Below the surface layer a relatively cold (<1°C), 

 and saline ( >32.67oo) water of Bering Sea origin 

 occupies the water column to near the bottom. 

 Farther north near Herald Shoal (70°20'N) the 

 presence of icemelt determines the surface water 

 characteristics, while the subsurface layer is still 

 of Bering Sea origin. 



Classification of water masses during the 

 winter in the eastern Chukchi Sea is lacking. 

 Practically all data taken in the Chukchi Sea have 

 been obtained in the summer. Comprehensive 

 work in the winter is required for a complete 

 understanding of the area. 



Freezing in the winter and melting in the sum- 

 mer creates distinct water masses in the eastern 

 Chukchi Sea and the shallowness of the sea make 

 wind and tidal energy particularly effective in 

 mixing water masses. Also the large surface area 

 of the sea increases the influence of the exchange 

 of heat in the waters. For these reasons there has 

 been a tendency to subdivide the waters of the 



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