Improved Current Estimates from Spar Buoy-Mounted ADCP Measurement Station: A Case Study in the Ligurian Sea

Abstract

Current measurements in the open sea are generally acquired by Acoustic Doppler Current Profilers (ADCPs). In the case of ADCPs mounted on spar buoy, current profiles require to be post-processed, to properly take into account the buoy influence: in fact, ADCP compass may reflect alterations induced by the metal structure of the buoy and apparent currents can occur due to the large displacement of the platform. Uncertainty analysis is finally required to properly consider both these effects and to compute robust velocity estimates. A new methodology is tested for a measurement station in the Ligurian Sea, where an ADCP was mounted on the surface buoy of the W1-M3A (Western 1 Mediterranean Moored Multisensor Array) oceanographic observatory, facing upwards at the depth of about 40 m. Marine current numerical models and historical data in the area have been used as a basis for comparison to test the consistency of the proposed method. A very good agreement is obtained. Only minor discrepancies are reported (e.g., monthly averages from the reference model slightly underestimate the west-east current component along the entire profile), but, in general, the application of the proposed methodology ensures that the spar buoy-mounted ADCP system is able to provide reliable measurements for oceanographic studies and validation of 3D hydrodynamic models.

Marine GIS as a Tool to Support Backscatter Data Analysis for Zooplankton Investigations

“…support scientists in the data analysis; results are discussed in Section 5. Time-series of ADCP data from the fixed position were obtained during the period 30/3-29/8 2017 from a Nortek Aquadopp Profiler (400 kHz) operated by ENEA and lo cated on the W1-M3A observatory, in the center of the Ligurian Sea [25] on a sea bed o 1200 m operating in the first 30 m of the water column in an upward looking configura tion.…”

“…The paper is structured as follows: Section 2 provides an overview of the used data set and the implemented software tool; Section 3 is devoted to the description of the observed migration pattern; Section 4 shows the capability of the proposed tool to effectively support scientists in the data analysis; results are discussed in Section 5. Time-series of ADCP data from the fixed position were obtained during the period 30 March-29 August 2017 from a Nortek Aquadopp Profiler (400 kHz) operated by ENEA and located on the W1-M3A observatory, in the center of the Ligurian Sea [25] on a sea bed of 1200 m operating in the first 30 m of the water column in an upward looking configuration.…”

Marine Metrology and Oceanographic Measurements 2020

“…However, the operations of current profilers still lack metrological controls. A. Bordone et al [1] present a procedure to carry out a proper uncertainty analysis for current meters mounted on spar buoys where current profiles need to be post-processed to account for the influence of the buoys. The methodology was tested for a measurement station in the Ligurian Sea, Italy.…”