TY - GEN
T1 - On the accuracy of computing slope current transports from current meter arrays
AU - Hátun, Hjálmar
PY - 2001/1
Y1 - 2001/1
N2 - Oceanographic data from a section to the north of the Faroe Islands are analyzed. These data come from ADCP current instruments deployed in the period 1994 to 1999, Aanderaa current meters deployed during two weeks in June ’86, and hydrographic (CTD) data from this section sampled three to six times a year in the period 1987 to 1999. A combination of these data is used to establish an annually averaged current profile for this section, and an estimate for the volume flux is calculated from this profile. Averaged volume fluxes in the years 1997 and 1998, are found to be 4.17 Sv (Sv = 10ˆ6 m³/s) and 4.56 Sv, respectively. The current has a strong vertical current shear, and it has a jet-like character with the core centered above the 600-650 m isobaths. A tidal model is employed to remove the tidal currents in the ADCP data, and the residual current from this analysis is used to describe the form of the current jet at short time-scales. This method finds the instantaneous horizontal current shear of the jet. Water level data from Tórshavn are adjusted with air pressure measurements, and the adjusted sea-level is compared to current velocities and volume fluxes. Negative correlations are found from this analysis. Based on all this information, suggestions are given of where to deploy future current instruments to get the best data from the fewest instruments used.
AB - Oceanographic data from a section to the north of the Faroe Islands are analyzed. These data come from ADCP current instruments deployed in the period 1994 to 1999, Aanderaa current meters deployed during two weeks in June ’86, and hydrographic (CTD) data from this section sampled three to six times a year in the period 1987 to 1999. A combination of these data is used to establish an annually averaged current profile for this section, and an estimate for the volume flux is calculated from this profile. Averaged volume fluxes in the years 1997 and 1998, are found to be 4.17 Sv (Sv = 10ˆ6 m³/s) and 4.56 Sv, respectively. The current has a strong vertical current shear, and it has a jet-like character with the core centered above the 600-650 m isobaths. A tidal model is employed to remove the tidal currents in the ADCP data, and the residual current from this analysis is used to describe the form of the current jet at short time-scales. This method finds the instantaneous horizontal current shear of the jet. Water level data from Tórshavn are adjusted with air pressure measurements, and the adjusted sea-level is compared to current velocities and volume fluxes. Negative correlations are found from this analysis. Based on all this information, suggestions are given of where to deploy future current instruments to get the best data from the fewest instruments used.
M3 - Other contribution
VL - 01
T3 - Havstovan Technical Reports
PB - Havstovan - Faroe Marine Research Institute
CY - Tórshavn
ER -
