The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder . easternberings00hood Year: 1981 ^ Anticipated oil-ice interactions 227 ' 1^ J ; Figure 14-6. LANDSAT image of tlie polynya soutii of St. Lawrence Island for 17 March 1976. within the grease-ice plumes ranges from 15 to 45 percent and that the thickness of the ice varies from to m in the laboratory to more than 1 m in the field. Also, our experiments show that because grease ice has a nonlinear viscosity, which increases as both the ice concentration increases and the shear rate
The Eastern Bering Sea Shelf : oceanography and resources / edited by Donald W. Hood and John A. Calder . easternberings00hood Year: 1981 ^ Anticipated oil-ice interactions 227 ' 1^ J ; Figure 14-6. LANDSAT image of tlie polynya soutii of St. Lawrence Island for 17 March 1976. within the grease-ice plumes ranges from 15 to 45 percent and that the thickness of the ice varies from to m in the laboratory to more than 1 m in the field. Also, our experiments show that because grease ice has a nonlinear viscosity, which increases as both the ice concentration increases and the shear rate decreases, it is an excellent wave absorber. Fig. 14-10, adapted from Pollard (1977) shows a schematic diagram of the Langmuir circulation which accompanies the formation of grease ice. The combi- nation of the bi-directional wind-wave spectra and the mean wind drift leads to the formation of alternating roll vortices in the ocean, where the grease ice accu- mulates in the convergence zones. This also suggests that, if oil is emulsified into small droplets by the wave breaking, these droplets may circulate around in the Langmuir rotors, as well as pile up in the conver- gence zones. Pollard (1977) states that typical con- vergence zone separations range from 5 to 300 m, and that rotor downweUing velocities are observed to be between 20 and 60 mm/sec. Further, the recent theoretical work of Craik and Leibovich (1976) sug- gests that the accumulation of a viscous substance such as oil or grease ice in the convergence zones will, by transforming the wave momentum into an additional mean current, intensify the rotor veloci-
Size: 2161px × 925px
Photo credit: © Bookend / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: archive, book, drawing, historical, history, illustration, image, page, picture, print, reference, vintage
