scholarly journals Hydrographic data from Endeavor 214 : a study of the Gulf Stream - Deep Western Boundary Current crossover

1992 ◽  
Author(s):  
Robert S. Pickart ◽  
Theresa K. McKee ◽  
William M. Smethie
Keyword(s):  
Gulf Stream ◽  
Western Boundary Current ◽  
Western Boundary ◽  
Boundary Current ◽  
Hydrographic Data ◽  
Deep Western Boundary Current

scholarly journals Adjustment of the basin-scale circulation at 26° N to variations in Gulf Stream, deep western boundary current and Ekman transports as observed by the Rapid array

2009 ◽  
Vol 6 (1) ◽  
pp. 871-908 ◽  
Author(s):  
H. L. Bryden ◽  
A. Mujahid ◽  
S. A. Cunningham ◽  
T. Kanzow
Keyword(s):  
Gulf Stream ◽  
Pressure Fluctuations ◽  
Western Boundary Current ◽  
Western Boundary ◽  
Pressure Measurements ◽  
Bottom Pressure ◽  
Boundary Current ◽  
The Bahamas ◽  
Deep Western Boundary Current ◽  
Basin Scale

Abstract. The Rapid instrument array across the Atlantic Ocean along 26° N provides unprecedented monitoring of the basin-scale circulation. A unique feature of the Rapid array is the combination of full-depth moorings with instruments measuring temperature, salinity, pressure time series at many depths with co-located bottom pressure measurements so that dynamic pressure can be measured from surface to bottom. Bottom pressure measurements show a zonally uniform rise (and fall) of bottom pressure of 0.015 dbar on a 5 to 10 day time scale, suggesting that the Atlantic basin is filling and draining on a short time scale. After removing the zonally uniform bottom pressure fluctuations, bottom pressure variations at 4000 m depth against the western boundary compensate instantaneously for baroclinic fluctuations in the strength and structure of the deep western boundary current so there is no basin-scale mass imbalance resulting from variations in the deep western boundary current. After removing the mass compensating bottom pressure, residual bottom pressure fluctuations at the western boundary just east of the Bahamas balance variations in Gulf Stream transport. Again the compensation appears to be especially confined close to the western boundary. Thus, fluctuations in either Gulf Stream or deep western boundary current transports are compensated in a depth independent (barotropic) manner very close to the continental slope off the Bahamas. In contrast, compensation for variations in wind-driven surface Ekman transport appears to involve fluctuations in both western basin and eastern basin bottom pressures, though the bottom pressure difference fluctuations appear to be a factor of 3 too large, perhaps due to an inability to resolve small bottom pressure fluctuations after removal of larger zonal average, baroclinic, and Gulf Stream pressure components. For 4 tall moorings where time series dynamic height (geostrophic pressure) profiles can be estimated from sea surface to ocean bottom and bottom pressure can be added, there is no general correlation between surface dynamic height and bottom pressure.

Sign in / Sign up

Export Citation Format

Share Document