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| Titel |
Seasonal thermal structure variations of Lake Geneva using 3D finite element modeling |
| VerfasserIn |
Anh Dao Le T., Francesca De Pascalis, Georg Umgiesser, Walter Wildi |
| Konferenz |
EGU General Assembly 2011
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 13 (2011) |
| Datensatznummer |
250053249
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| Zusammenfassung |
| A three-dimensional finite element model with the capacity to simulate water movements and
temperature structure was applied to Lake Geneva (Switzerland and France). The finite
element grid, joined with bathymetric data, has a resolution of 8149 triangular elements and
4553 nodes covering the two sections of the lake: “Petit Lac” (70m maximum water depth)
and “Grand Lac” (309m maximum water depth). The aim of this work was the investigation
of processes of water exchange between two basins and hydrodynamical - thermal structures
that occur during a year in the Lake Geneva using a numerical tool. Model code solves
conservation equations for mass, momentum and temperature transport, which
provide water temperature, current velocities and current directions. The model was
run for a one-year period (year 2005) with continued meteorological data: wind
speed and direction, air temperature, incident solar radiation, relative humidity,
precipitation and cloud cover factor; and hydrological data: tributary discharge and
temperature. This paper mainly investigates temperature structure of the lake during a
one-year cycle; however, it also shows the relationship between current regimes and
thermal structure. Temperature vertical profiles and horizontal distribution derived
from the model were analysed and compared with field data. The application of the
3D numerical model allows investigating the seasonal evolution of the thermal
regime, the thermal stratification, accumulation and release of heat and the winter
mixing within and between the two lake basins. The model results integrated with
the historical knowledge about the hydrodynamical processes in the Lake Geneva
allowed to better investigate the variability of these phenomena during the year
and the differences between the responses of the two sub-basins water masses. |
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