Numerical modeling of thermal bar and stratification pattern in Lake Ontario using the EFDC model

Arifin, R. R., de Alwis Pitts, D. A., James, S. J. , Hamlet, A. F., Sharma, A. and Fernando, H. J. S. (2015) Numerical modeling of thermal bar and stratification pattern in Lake Ontario using the EFDC model. In: 58th Annual Conference on Great Lakes Research, 25 - 29 May 2015, Burlington, Vermont.


Item Type:Conference or Workshop contribution (Presentation)
Item Status:Live Archive


Thermal bar is an important phenomenon in large, temperate lakes like Lake
Ontario. Spring thermal bar formation reduces horizontal mixing, which in turn, inhibits the
exchange of nutrients. Evolution of the spring thermal bar through Lake Ontario is
simulated using the 3D hydrodynamic model Environmental Fluid Dynamics Code (EFDC).
The model is forced with the hourly meteorological data from weather stations around the
lake, flow data for Niagara and St. Lawrence rivers, and lake bathymetry. The simulation is
performed from April to July, 2011; on a 2-km grid. The numerical model has been
calibrated by specifying: appropriate initial temperature and solar radiation attenuation
coefficients. The existing evaporation algorithm in EFDC is updated to modified mass
transfer approach to ensure correct simulation of evaporation rate and latent heatflux.
Reasonable values for mixing coefficients are specified based on sensitivity analyses. The
model simulates overall surface temperature profiles well (RMSEs between 1-2°C). The
vertical temperature profiles during the lake mixed phase are captured well (RMSEs <
0.5°C), indicating that the model sufficiently replicates the thermal bar evolution process. An
update of vertical mixing coefficients is under investigation to improve the summer thermal
stratification pattern. Keywords: Hydrodynamics, Thermal BAR, Lake Ontario, GIS.

Keywords:Lake Ontario, Thermal Bar, hydrodynamics
Subjects:F Physical Sciences > F851 Applied Environmental Sciences
F Physical Sciences > F850 Environmental Sciences
F Physical Sciences > F810 Environmental Geography
Divisions:College of Science > School of Geography
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ID Code:29668
Deposited On:24 Nov 2017 14:11

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