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Abstract: A bioenergetics Individual Based Model (IBM) is developed to simulate the early growth (age 0 to 43d) of Arctic cod hatched from mid-May to mid-July in the Northeast Water (NEW) in 1993 and the North Water (NOW) in 1998. In the model, the growth of a virtual larva is forced by observed temperature and prey concentrations as dictated by its hatch date. The functional response of food consumption to temperature in the range −1.8 to +1.6°C was estimated based on the gut content of field-captured larvae. A sensitivity analysis indicated that high prey concentrations could compensate the depressing effect of low temperature on growth and vice-versa. The IBM reproduced well the observed differences in mean length-at-age between the two polynyas/years, in particular the poor growth in the North Water. In the NEW, a temporal match between yolk exhaustion and good feeding conditions occurred for early hatchers (abundant prey — medium temperature) and mid-season hatchers (medium prey — high temperature), which reached the largest sizes. In the NOW, prey concentrations were generally low at yolk exhaustion and variations in growth among cohorts depended essentially on temperature. Sub-sampling the model output to mimic the limited temporal resolution of sampling at sea reduced the variability in virtual growth and increased the match between simulated and observed variances in length-at-age. The IBM nevertheless underestimated the observed exceptional growth during match events. [Copyright &y& Elsevier]

The North Water polynya, the largest polynya in the world, forms annually and recurrently in Smith Sound in northern Baffin Bay. Its formation is governed in part by the formation of an ice bridge in the narrow channel of Nares Strait below Kane Basin. Here, the widely used elastic–viscous–plastic elliptical rheology dynamic sea ice model is applied to the region. The idealized case is tested over a range of values for e = [1.2, 2.0] and initial ice thicknesses from 0.75 to 3.5 m, using constant northerly winds over a period of 30 days, to evaluate long-term stability of different rheological parameterizations. Idealized high-resolution simulations show that the formation of a stable ice bridge is possible for e ≤ 1.8. The dependence of the solution in terms of grid discretization is studied with a domain rotated 45°. A realistic domain with realistic forcing is also tested to compare time-variant solutions to actual observations. Cohesion has a remarkable impact on if and when the ice bridge will form and fail, assessing its importance for regional and global climate modeling, but the lack of observational thickness data during polynya events prevents the authors from identifying an optimal value for e. [ABSTRACT FROM AUTHOR]

Copyright of Atmosphere - Ocean (Canadian Meteorological & Oceanographic Society) is the property of Canadian Meteorological & Oceanographic Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atmosphere - Ocean (Canadian Meteorological & Oceanographic Society) is the property of Canadian Meteorological & Oceanographic Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atmosphere - Ocean (Canadian Meteorological & Oceanographic Society) is the property of Canadian Meteorological & Oceanographic Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atmosphere - Ocean (Canadian Meteorological & Oceanographic Society) is the property of Canadian Meteorological & Oceanographic Society and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article focuses on the physical processes within the North Water (NOW) Polynya at northern Baffin Bay in North Atlantic Ocean. Polynyas are large areas of open water or reduced ice cover in the midst of the thick ice pack that cover polar oceans during much of the year. The NOW Polynya is amongst the most productive marine areas north of the Arctic circle. The natural Sciences and Engineering Research Council funded a 4-year study, dedicated to examining the nature of the physical and biological coupling in the NOW Polynya. The results of the study is detailed.