Numerical Modeling of the Arctic Ocean Deepwater Formation: Part II. Results of Regional and Global Experiments

In this study the specific features of deepwater generation in an area of wind polynia and the capability of numerical models to transport bottom-density anomalies from shelf to deepwater areas are considered. The results of regional modeling indicate that the displacement method presented in the first part of this study leads to a considerable supply of dense deep waters at the expense of waters generated in shelf areas of the Barents and Kara seas. With the help of the given parametrization, these waters are shown to be able to numerically transport at significant distances from where they are generated to a shelf edge and deepwater oceanic areas with slightly changed initial density characteristics. This technique was tested within a large-scale combined ocean-ice model for the Arctic Ocean and the North Atlantic. With the displacement method, the numerical model was shown to have a less clearly expressed trend of decreasing the total amount of deep waters. However, this method does not eliminate the problem of adequately reproducing bottom waters in a large-scale numerical model. Based on a trend analysis of the numerical results, we found that a longer period of atmospheric influence with a prevalent cyclonic circulation leads to a decreased amount of deep waters in the Arctic Ocean, while a prevalent anticyclonic-type circulation leads to its recovery.