Investigating Tidal Energy in the Subtropical Atlantic

In July/ August 2017 a TRR 181 research team supervised by Dr. Maren Walter from University Bremen explored the dispersion of Tidal Energy along a path from the southern Azores to the Cap Verde Islands on board of the research vessel Poseidon.

Mooring deployment: (left) The yellow top float houses an acoustic current profiler. It will be monitoring the currents in the upper 250 m. (centre) The smaller current meters are combined with temperature loggers to obtain time series of current velocity and temperature at the same depths. (right) The instruments are attached to floatation. The floatation holds the mooring upright in the water and brings it back to the surface at the end of the deployment period. To the left of the instruments is the 1.4 t anchor made of massive steel sheets.

This summer, W2 scientist Dr. Maren Walter led the 516th cruise of the research vessel (RV)  Poseidon to the subtropical east Atlantic south of the Azores, starting July 29 and returning to harbour August 18.

During the three week cruise starting and ending in Ponta Delgada on the Azores, there were nine people on board, scientists and students from Bremen and Hamburg working in the TRR 181 projects W2 and W1. The task of the cruise was to measure energy fluxes along a tidal beam that emanates from the seamounts south of the Azores and was identified prior to the cruise using satellite altimetry. Seven times series stations were occupied along the tidal beam with CTD/LADCP profiles to infer internal wave energy fluxes. Additionally a mooring was deployed within the tidal beam to observe long-term temporal variability of the energy flux. It is equipped with current meters and temperature logger to record data over the course of one year. It will be recovered during the next cruise in May 2018.

 

 

Would you like to know more details about the cruise?

Weekly reports written by Dr. Maren Walter (German only)

 

 

Photos: Janna Köhler, Jonas Löb, Florentina Münzner, Simon Rümmler

 

  • POSEIDON at anchor at Ponta Delgada

  • View from POSEIDON offshore to the mainland

  • Preparing the floatation devices

  • Send-off for the CTD/LADCP system on RV Poseidon

  • The yellow instruments are the currents meters (LADCP), the grey tubes the water sampling bottles. The CTD is attached perpendicular below the frame.

  • Acoustic pre-deployment check of mooring instrumentation

  • In the lab: incoming data