Time-Lapse Acoustic Imaging of Mesoscale and Fine-Scale Variability within the Faroe-Shetland Channel ...

• Main Authors: Dickinson, A, White, NJ, Caulfield, CP
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union (AGU) 2020
• Subjects: 37 Earth Sciences; 3708 Oceanography; 3706 Geophysics; Tilting; Nordic Seas
• Online Access: https://dx.doi.org/10.17863/cam.53728; https://www.repository.cam.ac.uk/handle/1810/306642

AbstractWe describe and analyze the results of a three‐dimensional seismic (i.e., acoustic) reflection survey from the Faroe‐Shetland Channel that is calibrated with near‐coincident hydrographic and satellite observations. 54 vertical seismic transects were acquired over a period of 25 days. On each transect, a 250‐ to 400‐m‐thick band of reflections is observed within the water column. Hydrographic measurements demonstrate that this reflective band is caused by temperature variations within the pycnocline that separates warm, near‐surface waters of Atlantic origin from cold, deep waters that flow southward from the Nordic Seas. Tilting of reflective surfaces records geostrophic shear between these near‐surface and deep waters. Measurements of temporal changes of pycnoclinic depth and of reflection tilt are used to infer the existence of an anticyclonic vortex that advects northeastward. Comparison with satellite measurements of sea‐surface temperature and height suggests that this vortex is caused by ...