The Antarctic Circumpolar Current (ACC), a prominent ocean current that flows around Antarctica, is an important component of global ocean circulation and climate.
The current consists of a number of fronts. Observations indicate that turbulent mixing is enhanced in these fronts, penetrating through much of the water column.
Noting that understanding the ACC is important to understanding regional and global ocean circulation, Saenko feeds a simple representation of mixing along the current's fronts into a global climate model to evaluate the mixing's potential impact on ocean's overturning circulation.
For example, in the northern Atlantic Ocean, cold, dense water (called North Atlantic Deep Water, or NADW) sinks, travels south, and upwells around the latitudes of the ACC. Saenko finds that frontally intensified mixing in the ACC increases the transformation of NADW into Upper Circumpolar Deep Water (UCDW), a water mass that is a mixture of deep waters from the world's oceans and that contributes to upwelling in the Southern Ocean.
Further, the frontally intensified dense water upwelling in the Southern Ocean diverts a fraction of Antarctic Bottom Water, which heads north from the ACC, back to the UCDW.
- Saenko et al. Influence of the enhanced mixing within the Southern Ocean fronts on the overturning circulation. Geophysical Research Letters, 2008; 35 (9): L09602 DOI: 10.1029/2008GL033565
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