Ocean water is constantly moving, and not just in the form of waves and tides. Ocean currents flow like vast rivers at the surface, while others flow deep within water, playing a key role in determining how the ocean distributes heat energy throughout the planet, thereby regulating and stabilizing climate patterns, and delivering nutrients to marine ecosystems.
Measuring currents is a fundamental practice in the field of oceanography. By determining how ocean water moves, scientists can determine how the currents affects the regulation of local weather conditions, as well as how organisms, nutrients, and other biological and chemical constituents are transported throughout the ocean. That’s where an efficient tool – Acoustic Doppler Current Profilers (ADCPs) – comes in, helping the EMSO ERIC scientific community to measure the speed and direction of water currents across diverse sites in the European Seas.
The EMSO Engineering and Logistics Service Group has set up several Working Groups of systems or sensors experts aimed at implementing harmonisation questions from the engineering and operational point of view and agreeing on technical decisions. One of the Working groups is focused on ADCPs.
In the framework of the MINKE EU funded project, the EMSO ADCP working group was successfully awarded grant-aid for a TransNational Access (TNA) to access the platform for ADCP compass and tiltmeter calibration, as well as transducers integrity verification at the French Naval Hydrographic and Oceanographic Service (SHOM) in Brest, France.
The access project unfolded in two phases across 2024 and 2025, focused on testing and calibrating ADCPs both in pre and post-deployment to identify any measurement errors caused by inaccuracies in their compass or tilt sensors. These tests at SHOM’s advanced facilities provided EMSO’s ADCP team, made by representatives from the ERIC’s Regional Facilities SmartBay, Nordic Sea, South Adriatic Sea, Ligurian Sea and Iberian Margin, with invaluable insights into calibration and maintenance operations.
The collaboration between EMSO and SHOM representatives paved the way also to the realisation of the abstract “Best practices on pre- and post-deployment procedures for Acoustic Doppler Current Profilers”. The document, which will expanded upon in a forthcoming scientific paper and will be the subject of a presentation for the OCEANS 2025 conference, in Brest, next June, outlines the work on ADCP calibration and data quality and proposes a pre- and post-deployment checklist for ADCPs to improve the awareness of the quality (in terms of accuracy) of the data collected by this instrumentation and prevent biases caused by magnetic filed anomalies generated by batteries or other instrumentation in the proximity of the compass or sensor drifts, both before and after deployment. In the upcoming future, the EMSO ADCP working group aims to develop a comprehensive guide outlining best practices for ADCP usage within the EMSO network, which will serve as a valuable resource for ensuring the quality and consistency of data collected by EMSO for its stakeholders.
Looking ahead, the EMSO Engineering and Logistics Service Group’s goal, in alignment with MINKE’s goal of enhancing the accuracy of data, is to enhance the work also on the calibration of the CTD and Oxygen sensors, which represent, along with the ADCP, fundamental tools within the ERIC framework for the deep ocean observation. EMSO will foster collaboration with ADCP manufacturers to improve calibration and data quality and plans to develop webinar/training programs on ADCP best practices, promoting optimal utilisation of this technology within and outside the ERIC’s community.
Fig. 1 ADCP calibration at SHOM
Fig. 2 HCMR team working on CTD (left, up) and Oxygen sensor calibration bench (left, down). Preliminary overview of sensor types used in the EMSO framework (right)