Poleward propagation of spiciness anomalies in the North Atlantic Ocean
Article first published online: 6 JUL 2006
Copyright 2006 by the American Geophysical Union.
Geophysical Research Letters
Volume 33, Issue 13, July 2006
How to Cite
2006), Poleward propagation of spiciness anomalies in the North Atlantic Ocean, Geophys. Res. Lett., 33, L13603, doi:10.1029/2006GL026155., , , , and (
- Issue published online: 6 JUL 2006
- Article first published online: 6 JUL 2006
- Manuscript Accepted: 30 MAY 2006
- Manuscript Revised: 19 MAY 2006
- Manuscript Received: 27 FEB 2006
 Recent modelling results suggest that subsurface salinity anomalies propagating from the tropics can reach and precondition the deep-water formation regions, thus modulating the THC variability. The forcing and propagative aspects of this mechanism are presented in the North Atlantic Ocean over 1948–2002 using an OGCM. Density compensated salinity anomalies of 0.1 up to 0.35 psu along σ = 26 kg.m−3 are generated in the salinity maximum region at interannual to decadal frequency. The relation between subsurface conditions and late winter sea surface salinity variability supports the subduction mechanism. They circulate over isopycnals ranging from 25.6σ to 26.2σ at current speed between 150 m and 250 m depth toward Cape Hatteras via the Gulf of Mexico on a typical 6-year transit. Although mixing along the pathway reduces the amplitude of salinity anomalies by about 66%, they largely determine the subsurface spiciness of the Gulf Stream up to 30°N, upstream of the outcrop region.