Variability of Antarctic Bottom Water at 24.5°N in the Atlantic
Article first published online: 17 NOV 2011
Copyright 2011 by the American Geophysical Union.
Journal of Geophysical Research: Oceans (1978–2012)
Volume 116, Issue C11, November 2011
How to Cite
2011), Variability of Antarctic Bottom Water at 24.5°N in the Atlantic, J. Geophys. Res., 116, C11026, doi:10.1029/2011JC007168., , , and (
- Issue published online: 17 NOV 2011
- Article first published online: 17 NOV 2011
- Manuscript Accepted: 6 SEP 2011
- Manuscript Revised: 1 SEP 2011
- Manuscript Received: 28 MAR 2011
- Antarctic Bottom Water;
- deep water transport;
- ocean circulation
 A recent hydrographic section at 24.5°N in the Atlantic and 6 months of observations from a moored array show that Antarctic Bottom Water (AABW), the densest and deepest water mass in the world oceans, has been warming. While Johnson et al. (2008) showed that northward AABW transport at 24.5°N has been declining from 1981 to 2004, suggesting that the lower cell of the overturning circulation could halt in the near future, estimates from the latest hydrographic section in 2010 indicate a partial recovery of northward AABW transport. From 6 months of temperature and salinity observations at a deep moored array at 24–26°N, we find that short-term variability between April and November 2009 is of the same magnitude as the changes observed from hydrographic sections between 1981 and 2004. These observations highlight the possibility that transport changes estimated from hydrographic sections may be aliased by short-term variability. The observed AABW transport variability affects present estimates of the upper meridional overturning circulation by ±0.4 Sv (1 Sv = 106 m3s−1).