Arduino controlled valvometry equipment for mussel raft monitoring

High-Frequency Non-Invasive (HFNI) instruments are currently used in bivalve mollusks in order to use them as bio-indicators of the local conditions of the environment. Under the STRAUSS project an Arduino controlled equipment has been developed to log the valve movements activity of mussels (Mytilus galloprovincialis) using Hall-effect sensors. The equipment is able to record at 10Hz the signals of 27 Hall-sensors, temperature, fluorescence and , to store the records in internal microSD cards and to send the stream of data to in premisses data servers for storing and plotting them.Peer Reviewe

Hydrographic variability (1994-2020) in the Ría de Vigo and adjacent shelf (NW Iberia)

The Spanish Institute of Oceanography (IEO-CSIC) carries out monthly oceanographic samplings at across-shelf sections off the northern Spanish coast under the monitoring program RADIALES (https://www.seriestemporales-ieo.net/). This is a multidisciplinary marine research effort addressing long-term variability issues at the ecosystem level (Bode et al., 2015; Valdés et al., 2002). Currently, the monitoring program includes 5 perpendicular coastal transects in Northern Spain: Santander, Gijón, Cudillero, A Coruña and Vigo. Focusing on the section located in the Ría de Vigo and adjacent shelf, we have analysed a 27-year time series (1994 - 2020) of temperature and salinity obtained through CTD profiles in three stations, two inside the Ría (~30 and ~40 m depth) and one in the mid-shelf (~90 m depth). This study summarizes the hydrographic variability in the region through the construction of a local climatology. In addition, long-term trends and interannual changes in seasonality are examined. The results show a change in the salinity regime in medium depth waters in 2013, although not in temperature. Near the surface, the temperature undergoes a negative shift from 2016, in correspondence with the entry of the AMO into a new negative phase

SPOT and GPRS drifting buoys for HF Radar calibration

Traditional drifting buoys have been designed to measure the surface currents at a nominal depth of 15m with drogues of 6m height. Herein, in order to assess the performance of HF Radars two designs of Lagrangian drifting buoys have been developed and targeted to provide the vertically averaged velocity of the currents in the frst 2 and 0.5 meters of the water column. These are the layer heights of the HF Radars of RAIA observatory. The buoys were made with standard materials and of-the-shelf electronics, to keep costs as low as possible.Peer Reviewe

Model type II regression for lagrangian validation of HF radar velocities in the NW Iberian Peninsula

Two designs of lagrangian low-cost drifting buoys have been developed in order to monitor the ocean surface dynamics in the North-west Iberian Peninsula and provide ground-truth observations that can be used to assess the performance of High Frequency (HF) Radars of RAIA observatory from 2020 to 2022. Since regression model type I, which is typically used in buoy-HF radar antennas validations, does not consider the presence of errors in the observations from both instruments, regression model type II was proposed to instrument intercomparison. Furthermore, a new metric was developed to better assess both model types regressions in lagrangian validations.Peer Reviewe

Radar on RAIA: High frequency radars in the RAIA Observatory

The RADAR ON RAIA project aims to update and extend beyond the Galician border the High Frequency (HF) radar network that has been operating since 2011 in the framework of the RAIA Observatory. The Project is allowing the establishment of a cross-border collaboration beyond the physical infrastructure itself, developing a sharing strategy of maintenance procedures, validation and data processing on both sides of the border, as well as an easy and public access to all the information. In addition, new products are being developed to exploit the potential of the HF radar technology.Peer Reviewe