Modelling and measuring (by HF radar) dispersion in the coastal zone
Modelling and measuring (by HF radar) dispersion in the coastal zone
Sea surface currents measured by the OSCR II (Ocean Surface Current Radar) system in July - August 1990, as part of the FLUXMANCHE project, were used to obtain horizontal eddy diffusivity coefficients (EDC), divergence and vertical vorticity, on the French coastal side of the Strait of Dover. These measurements corresponded to a grid of 672 evenly spaced cells (1 km) covering a region of approximately 30x30 km2 and sampled every 20 minutes for a 22 days period. The projections of the local surface current vector (radial currents) along two fixed antennae (master/radial) were subject to an exhaustive "cleaning" process in order to remove the spikes, interpolate the gaps and recreate the vector current. A method based on restricting the acceleration on each radial current was used with an 80% of success rate.
A graphic interface was written to facilitate visual inspection of the numerous radial current data files and to combine them to produce the vector current. The EDC and kinematic variables were obtained through the adaptation of the Okubo and Ebbesmeyer's (1976) (OE) method to OSCR cells. Previously, OSCR cells were arranged in a diamond-like cluster of fixed diameter. The diameter of the cluster (4 km) was chosen in accordance to the Eulerian decorrelation time, TE=3 hr., as in Middleton et al., (1993), containing a constant number of 13 OSCR cells.
By overlapping clusters, results were reported at the same grid spacing as OSCR. Preliminary tidal analysis on the data, showed the predominance of the M2 tidal as the most energetic forcing frequency present. This semi-diurnal effect was sensed of the temporal and spatial distributions of the EDC and kinematic variables, which also were affected by local topographic features. (DX184244)
University of Southampton
1994
Castaneda, Julian Jose
(1994)
Modelling and measuring (by HF radar) dispersion in the coastal zone.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
Sea surface currents measured by the OSCR II (Ocean Surface Current Radar) system in July - August 1990, as part of the FLUXMANCHE project, were used to obtain horizontal eddy diffusivity coefficients (EDC), divergence and vertical vorticity, on the French coastal side of the Strait of Dover. These measurements corresponded to a grid of 672 evenly spaced cells (1 km) covering a region of approximately 30x30 km2 and sampled every 20 minutes for a 22 days period. The projections of the local surface current vector (radial currents) along two fixed antennae (master/radial) were subject to an exhaustive "cleaning" process in order to remove the spikes, interpolate the gaps and recreate the vector current. A method based on restricting the acceleration on each radial current was used with an 80% of success rate.
A graphic interface was written to facilitate visual inspection of the numerous radial current data files and to combine them to produce the vector current. The EDC and kinematic variables were obtained through the adaptation of the Okubo and Ebbesmeyer's (1976) (OE) method to OSCR cells. Previously, OSCR cells were arranged in a diamond-like cluster of fixed diameter. The diameter of the cluster (4 km) was chosen in accordance to the Eulerian decorrelation time, TE=3 hr., as in Middleton et al., (1993), containing a constant number of 13 OSCR cells.
By overlapping clusters, results were reported at the same grid spacing as OSCR. Preliminary tidal analysis on the data, showed the predominance of the M2 tidal as the most energetic forcing frequency present. This semi-diurnal effect was sensed of the temporal and spatial distributions of the EDC and kinematic variables, which also were affected by local topographic features. (DX184244)
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Published date: 1994
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Local EPrints ID: 458496
URI: http://eprints.soton.ac.uk/id/eprint/458496
PURE UUID: 3d2dfa87-23d0-46ec-98a9-176aee0308ae
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Date deposited: 04 Jul 2022 16:50
Last modified: 04 Jul 2022 16:50
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Author:
Julian Jose Castaneda
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