The circulation of Pacific water (located at depths between 50 and 200 m) in the Arctic Ocean may be coherent with the surface currents, but its pathways are not known from direct observations.
The Atlantic water circulates in the Arctic Ocean at approximately 200–800m deep. This water penetrates to the Arctic via Fram Strait and St. Anna Trough (Barents Sea). Under extensive surface cooling, it sinks to intermediate depths and forms the warm Atlantic Layer, with water temperatures greater than 0°C. This layer is covered by low-density surface waters and is thus prevented from undergoing heat exchange with the atmosphere. The most widely accepted circulation scheme of Atlantic water (Rudels et al., 1994) postulates that it circulates counterclockwise, forming several loops in the Arctic basins (Fig. 4, red arrows). The variability of the Atlantic water circulation pattern is not known from observations, but model results show that its circulation has a pulsating character expressed in the propagation of warm and cold events, changing from seasonal to decadal time scales.
Proshutinsky, A. Yu., and M. Johnson, 1997. Two circulation regimes of the wind-driven Arctic Ocean. Journal of Geophysical Research, 102, 12,493–12,514.
Proshutinsky, A. et al., 2005. Arctic Ocean Study: Synthesis of model results and observations, Eos Transactions, American Geophysical Union, 86(40), 368, 370.
Rudels, B., Jones, E.P., Anderson, L.G. and Kattner, G., 1994. On the intermediate depth waters of the Arctic Ocean. In: O.M. Johannessen, R.D. Muench and J.E. Overland (Editors), The Polar Oceans and their role in shaping the global environment: the Nansen centennial volume. Geophysical Monograph 85. American Geophysical Union, Washington DC, USA, pp. 33-46.