amination of the temperature structure of the deep 

 waters. Coachman and Barnes (1963), using the 

 "core-layer method" of Wust (1935), were able to 

 support Worthington's circulation of Atlantic 

 Water in the Beaufort Sea. The only satisfactory 

 resolution to the movement of Atlantic Water in 

 the Beaufort Sea will be through numerous direct 

 current measurements. 



Direct current measurements from T-3 ice is- 

 land at 150 m (pycnocline), 500 m (core of Atlan- 

 tic layer), and at 1300 m (Arctic Deep Water) 

 indicate that the flow is quite similar in the three 

 water masses and that the dominant mode of mo- 

 tion is barotropic (Coachman, 1969). The current 

 speed varied between and 8 cm/sec. 



The Beaufort Sea, like the rest of the Arctic, 

 seems to be a well aerated basin with a good 

 supply of dissolved oxygen (greater than 70% 

 saturation at all depths) (Coachman and Barnes, 

 1963; Sater, 1969). Concentrations of dissolved 

 oxygen in the Beaufort Sea have not been meas- 

 ured routinely so that a detailed description can 

 not be given for most of the region. Kinney, et al. 

 (1970) are the first to elucidate the detailed verti- 

 cal oxygen structure of the water column in the 

 northern Beaufort Sea from Fletcher's ice island 

 (T-3). They found that the most striking feature of 

 the oxygen profile other than the high surface 

 values ( >8.0 ml/1) was an oxygen minimum (6.0 

 ml/1) at 200 meters depth, about 50 meters below 

 the nutrient maximum. Kinney, et al. (1970) 

 speculate that the oxygen minimum is partially 

 due to advection processes rather than in situ 

 oxidation alone. Kusunoki et al. (1962) found a 

 minor maximum (6.9 ml/1) at 800 meter depth in 

 the southern Beaufort Sea. This water was 85% 

 saturated. Below this level the oxygen content 

 decreases gradually toward the bottom where the 

 value was about 6.5 ml/1 (81%). It is interesting 

 to note that Kusunoki et al. (1962) observed 

 slightly higher dissolved oxygen concentrations at 

 depths below 250 meters during the winter than in 

 the summer, particulary at levels between .500 to 

 1.300 meters. This suggests that one might be able 

 to observe subtle seasonal fluctuations in the At- 

 lantic layer. 



Recent work in the Arctic indicates that con- 

 centrations of nutrients are low in the surface 

 waters as well as in deep waters and do not vary 



appreciably throughout the year in the surface 

 water (Kawamure, 1967). Studies by McGill Uni- 

 versity (Marine Science Center, 1968) show that 

 high nutrient concentrations are associated with 

 the Pacific water layers at 75 meters depth and 

 160 meters depth in the Beaufort Sea. Kinney et 

 al. (1970) found the nutrient maximum at 160 

 meters to be associated with the temperature 

 minimum in the northern Beaufort Sea. Below 

 this layer, nutrient concentrations continue to 

 decrease to about 1500 meters and remain rela- 

 tively constant to the bottom of the northern 

 Beaufort Sea. Little is known about the nutrient 

 distribution in the southern Beaufort Sea or the 

 role of the rivers as a sourceof supply of nutrients. 

 Kusunoki et al. (1962) observed relatively high 

 silicate concentrations (>15)Mg-at/l) in the sur- 

 face waters just north of Point Barrow and sug- 

 gested that the concentrations may be due to river 

 runoff or from Pacific waters passing through the 

 Bering Strait. 



RESULTS OF WEBSEC-71 AND 72 



Data Collection and Processing 



WEBSEC-71 was conducted from the USCGC 

 GLACIER (WAGB-4) and RV NATCHIK in the 

 western Beaufort Sea during 17 August to 20 

 September, 1971. From the GLACIER seventy- 

 two stations were taken in the vicinity of Barter 

 Island to Cape Halkett (fig. 2). Physical and 

 chemical oceanographic data were collected at 

 these stations from 48 Nansen bottle casts, 21 

 STD'S (salinity-temperature-depth recorder), 

 163 expendable bathythermograph (XBT) drops, 

 and 5 current meter lowerings. Forty-five Nansen 

 bottle casts were taken from the NATCHIK (fig. 



2). 



WEBSEC-72 was conducted from the USCGC 

 GLACIER and RV NATCHIK in the western 

 Beaufort Sea during 2 August to 12 September, 

 1972 (fig. 3). Physical and chemical oceano- 

 graphic data were collected on the GLACIER at 

 seventy-two stations from 94 Niskin bottle casts, 

 21 STD's, 60 expendable bathythermograph 

 (XBT) drops and 63 current meter lowerings. 

 Forty-five hydrographic stations were taken by 

 the NATCHIK. 



