The Relation between Decadal Variability of Subtropical Mode Water and the North Atlantic Oscillation*

Top Cited Papers
Publisher Website
Google Scholar
Abstract
The Bermuda station “S” time series has been used to define the variability of subtropical mode water (STMW) from 1954 to 1995. This record, which shows decadal variability at a nominal period of about 12–14 yr, has been used as a baseline for seeking correlation with large-scale atmospheric forcing and with decadal north–south excursions of the Gulf Stream position defined by the subsurface temperature at 200-m depth. A common time period of 1954–89 inclusive, defined by the data sources, shows a high degree of correlation among the STMW potential vorticity (PV), Gulf Stream position, and large-scale atmospheric forcing (buoyancy flux, SST, and sea level pressure). Two pentads with anomalously small and large STMW PV were further studied and composites were made to define a revised North Atlantic Oscillation (NAO) index associated with the decadal forcing. During years of low PV at Bermuda, the NAO index is low, the Gulf Stream is in a southerly position, and the zero wind stress curl latitude i... Abstract The Bermuda station “S” time series has been used to define the variability of subtropical mode water (STMW) from 1954 to 1995. This record, which shows decadal variability at a nominal period of about 12–14 yr, has been used as a baseline for seeking correlation with large-scale atmospheric forcing and with decadal north–south excursions of the Gulf Stream position defined by the subsurface temperature at 200-m depth. A common time period of 1954–89 inclusive, defined by the data sources, shows a high degree of correlation among the STMW potential vorticity (PV), Gulf Stream position, and large-scale atmospheric forcing (buoyancy flux, SST, and sea level pressure). Two pentads with anomalously small and large STMW PV were further studied and composites were made to define a revised North Atlantic Oscillation (NAO) index associated with the decadal forcing. During years of low PV at Bermuda, the NAO index is low, the Gulf Stream is in a southerly position, and the zero wind stress curl latitude i...

This publication has 0 references indexed in Scilit: