Comparison of Profiling Current Meter and Shipboard ADCP Measurements in the Western Equatorial Pacific

Thierry Delcroix Groupe SURTROPAC, Institut Français de Recherche Scientifique pour le Développement en Coopération, Orstom, Nouméa, New Caledonia

Search for other papers by Thierry Delcroix in
Current site
Google Scholar
PubMed
Close
,
François Masia Groupe SURTROPAC, Institut Français de Recherche Scientifique pour le Développement en Coopération, Orstom, Nouméa, New Caledonia

Search for other papers by François Masia in
Current site
Google Scholar
PubMed
Close
, and
Gérard Eldin Groupe SURTROPAC, Institut Français de Recherche Scientifique pour le Développement en Coopération, Orstom, Nouméa, New Caledonia

Search for other papers by Gérard Eldin in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

Profiling current meter (PCM) measurements under a drifting buoy are compared with concurrent shipboard acoustic Doppler current profiler (ADCP) measurements carried out in the western equatorial Pacific in March 1991, from 10°S to 7°N along the 165°E meridian. The mean (ADCP minus PCM)±rms differences between zonal and meridional velocity components are 5.7±11.2 cm s−1 and 0.0±8.8 cm s−1, respectively, when PCM measurements are relative to 600 m. The mean±rms differences decrease to 2.3±7.8 cm s−1 and 0.0±6.3 cm s−1 when the PCM and ADCP data are both referenced to the same layer (on a mean, 16–240 m). As compared with ADCP, it is found that PCM underestimates velocities of less than 20 cm s−1 by about 25%.

Abstract

Profiling current meter (PCM) measurements under a drifting buoy are compared with concurrent shipboard acoustic Doppler current profiler (ADCP) measurements carried out in the western equatorial Pacific in March 1991, from 10°S to 7°N along the 165°E meridian. The mean (ADCP minus PCM)±rms differences between zonal and meridional velocity components are 5.7±11.2 cm s−1 and 0.0±8.8 cm s−1, respectively, when PCM measurements are relative to 600 m. The mean±rms differences decrease to 2.3±7.8 cm s−1 and 0.0±6.3 cm s−1 when the PCM and ADCP data are both referenced to the same layer (on a mean, 16–240 m). As compared with ADCP, it is found that PCM underestimates velocities of less than 20 cm s−1 by about 25%.

Save