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| Titel |
Local Wind Influence on Freshwater Plume Behavior: Application to the Catalan Shelf. |
| VerfasserIn |
Maria Liste, Manel Grifoll, Jaak Monbaliu, Ingrid Keupers, Homayoon Komijani |
| Konferenz |
EGU General Assembly 2013
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 15 (2013) |
| Datensatznummer |
250080648
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| Zusammenfassung |
| Introduction
Freshwater fluxes are not always considered, and often their 3D character is neglected.
The “distributed” continental run-off is seldom taken into consideration. The main aim of the
EU-FP7 Field_Ac project (www.field_ac.eu), was to improve operational service for coastal
areas and to generate added value for shelf and regional scale predictions including land
discharge as a boundary condition. In this paper the dispersal of a fresh water plume in a
small part of the Catalan Coast (NW Mediterranean Sea) caused by a flash flood event in
March 2011 is presented in response to the local wind forcing. Observations and modeling
results are shown for a short period but with a large impact on the receiving coastal
waters.
Methodology and aim
For the coastal circulation model, version 3.0 of the Regional Ocean Modeling System
[ROMS, Shchepetkin and McWilliams, 2005] has been chosen. ROMS solves the 3-D
Reynolds-Averaged Navier-Stokes equations in sigma coordinates. The code design is
modular, so that different choices for advection and mixing, for example, may be applied by
simply modifying preprocessor flags. Nested increasing-resolution models have been
implemented in order to reproduce with sufficient spatial resolution the coastal circulation
and the river plume evolution in a small portion of the Catalan coastal area. The
boundary conditions for the largest domain model are obtained from the MyOcean
products.
River and urban run-off are estimated based on measured or predicted rainfall in the
contributing catchments areas. Conceptual models based on a reservoir-type schematization
of the river and sewer network have been set up to allow for fast prediction of the different
point source boundary conditions [Keupers et al., 2011].
Model output data are compared to in situ data from dedicated campaigns during
the Field_AC Project and to data from operational buoys in the Catalan coastal
area.
Results
Wind forcing leads to freshwater spreading. As expected, wind speed and direction and
the magnitude of the fresh water discharge affect substantially the plume behavior. This case
study illustrates clearly the need to consider both the wind forcing and the fresh water
discharge as part of a single system.
References
Field_AC project (www.field_ac.eu), EU- FP7-SPACE-2009-1-242284.
Keupers, I., Willems, P., Fernandez Sainz, J., Bricheno, L., Wolf, J., Polton, J., Howarth,
J., Carniel, S., Staneva, J. (2011). Methodology (including best practice guidelines) on how to
identify and incorporate ‘concentrated’ and ‘distributed’ run-off in pre-operational forecasts,
based on the input and requirements from our users. FIELD_AC project, D3.1, 90
pp.
MyOcean products (http://www.myocean.eu/).
Shchepetkin and McWilliams, 2005. The Regional Ocean Modeling System (ROMS): A
split-explicit, free-surface, topography-following coordinates ocean model. Ocean Modelling.
Vol. 9 pp. 347-404. |
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