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| Titel |
A one-dimensional model intercomparison study of thermal regime of a shallow, turbid midlatitude lake |
| VerfasserIn |
V. M. Stepanenko, A. Martynov, K. D. Jöhnk, Z. M. Subin, M. Perroud, X. Fang, F. Beyrich, D. Mironov, S. Goyette |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1991-959X
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| Digitales Dokument |
URL |
| Erschienen |
In: Geoscientific Model Development ; 6, no. 4 ; Nr. 6, no. 4 (2013-08-30), S.1337-1352 |
| Datensatznummer |
250084980
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| Publikation (Nr.) |
 copernicus.org/gmd-6-1337-2013.pdf |
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| Zusammenfassung |
| Results of a lake model intercomparison study conducted within the framework
of Lake Model Intercomparison Project are presented. The investigated lake
was Großer Kossenblatter See (Germany) as a representative of shallow,
(2 m mean depth) turbid midlatitude lakes. Meteorological measurements,
including turbulent fluxes and water temperature, were carried out by the
Lindenberg Meteorological Observatory of the German Meteorological Service
(Deutscher Wetterdienst, DWD). Eight lake models of different complexity were
run, forced by identical meteorological variables and model parameters
unified as far as possible given different formulations of processes. All
models generally captured diurnal and seasonal variability of lake surface
temperature reasonably well. However, some models were incapable of
realistically reproducing temperature stratification in summer. Total heat
turbulent fluxes, computed by the surface flux schemes of the compared lake
models, deviated on average from those measured by eddy covariance by
17–28 W m−2. There are a number of possible reasons for these
deviations, and the conclusion is drawn that underestimation of real fluxes
by the eddy covariance technique is the most probable reason. It is supported
by the fact that the eddy covariance fluxes do not allow to close the heat
balance of the water column, the residual for the whole period considered
being ≈–28 W m−2. The effect of heat flux to bottom sediments
can become significant for bottom temperatures. It also has profound
influence on the surface temperatures in autumn due to convective mixing but
not in summer when the lake stratification is stable. Thus, neglecting
sediments shifts the summer–autumn temperature difference in models lacking
explicit treatment of sediments considerably. As a practical recommendation
based on results of the present study, we also infer that in order to
realistically represent lakes in numerical weather prediction and climate
models, it is advisable to use depth-resolving turbulence models (or
equivalent) in favor of models with a completely mixed temperature profile. |
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