Acoustic Monitoring of the Fram Strait

The Nansen Center and collaborating partners have this week launched an acoustic tomography experiment in the Fram Strait as part of the DAMOCLES EU project. The first acoustic source and receivers were successfully deployed on 15th and 16th August from RV Håkon Mosby with Dr. Hanne Sagen as cruise leader.

The tomography system will measure travel time of sound signals in different depths of the water column. The data from the array will be recovered during summer 2009 and be converted to a year-long record of temperature measurements across the West Spitzbergen Current. A profiling CTD mooring was also deployed close to the source location and will be used to measure profiles of hydrography including sound speed every day.

From 2009 the array will be expanded with additional acoustic sources and receivers as part of the new ACOBAR project. A triangle of transceivers - a combination of a source and a receiver mooring - is marked by red circles (see figure). The array in the middle, marked by a blue dot (A), and the south-eastern source mooring (B) have now been deployed and the additional moorings C and D will be deployed in 2009. The pink arrows indicate the main branches of the northward flowing West Spitzbergen Current and the recirculation of Atlantic water masses in the centre of the Fram Strait. The white arrows pointing southward represent the East Greenland Current.

Combined with satellite remote sensing observations and ocean modelling the observations will significantly improve our capabilities to the monitor the variability currents across the Fram Strait using innovative monitoring technologies.

Further information: Prof. Stein Sandven (+47 99368440) or
Dr. Hanne Sagen (+47 93213296)