Iceland-Faeroe Front Structure and Variability
Abstract
During the period June 1991 to August 1993, 107 Argus-tracked drifters, drogued to 15 m depth, were released in the Greenland, Iceland, and Norwegian (GIN) Seas. The drifter movements revealed the strong and spatially confined current systems along the Iceland-Faeroe Front (IFF) and provided tracking of the Norwegian Atlantic Current and the general cyclonic gyre circulation in the GIN Sea. Of the 107 drifters released, 59 were selected for this study due to their proximity to the IFF. Tracked by the Argos system aboard the NOAA polar orbiters, the drifters provided accurate location and sea surface temperature (SST) data. Interpolated and low pass filtered position data were used to construct maps of drifter displacement and surface velocity field estimates and to study the correlation between drifter trajectories and satellite derived SST frontal features. Drifter SST data were compared to spatially and temporally coincident satellite retrieved SST data. The individual data sets were in good agreement with each other, resulting in a temperature difference of less than 1 deg C. Satellite imagery used to estimate surface currents through SST feature tracking provided a snapshot of the flow field over a short time scale. The drifters revealed a distinct frontal zone (IFF) where the topographically steered flow field approached velocities of 1 m/s. This relatively strong flow became unstable as it propagated eastward and an intense eddy field developed. What began as a stable demarcation between water masses became a flow field dominated by warm and cold instabilities and intrusions. This dynamic transformation occurred over relatively short time (less than 5 days) and distance (several hundred kilometers) scales, testament to the vigorous activity in the IFF. These Lagrangian drifter measurements compose the first comprehensive, accurate near-surface velocity data
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1997
- Accession Number
- ADA333436
Entities
People
- Christopher J. Arends
Organizations
- Naval Postgraduate School