Publication Details |
| Category | Text Publication |
| Reference Category | Preprints |
| DOI | 10.5194/egusphere-2025-1195 |
Licence  |
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| Title (Primary) | Thermobaric circulation in a deep freshwater lake |
| Author | Marks, J.
; Chikita, K.A.; Boehrer, B. |
| Source Titel | EGUsphere |
| Year | 2025 |
| Department | SEEFO |
| Language | englisch |
| Topic | T5 Future Landscapes |
| Abstract | Numerical lake models are a powerful tool to optimize water management
and mitigate changes due to climate change. Hence, detailed
implementation of lake specific processes is crucial to ensure optimal
results. However, common numerical lake models have so far omitted the
effect of thermobaricity despite its significant influence on deep water
circulation in deep lakes. The thermobaric effect is based on the
temperature dependence of the compressibility of water. As a
consequence, deep water can be significantly colder than 4 °C and deep
water renewal becomes complex. For a proper investigation, numerical
models can be appropriate tools to display and understand such processes
better. Inspired by Lake Shikotsu, which is an excellent example for
the influence of thermobaricity, we developed a simplified 1D model for
thermobaric effects. Here, we used in situ density to replace potential
density for stability considerations such as the Brunt-Väisälä
frequency. To prevent any competing influences and isolate thermobaric
effects, we excluded any external forcing except for the surface
temperature input. Accordingly, we excluded salinity, chose a
cylindrical bathymetry without shallow areas, and omitted any inflows.
Therefore, the model reproduced deep water circulation solely based on
thermal forcing at the surface. We were able to identify key features of
the deep water renewal events as well as different phases of the mixing
period. Additionally, we investigated the influence of previous deep
water renewal events and the current surface temperature on the deep
water circulation. Our results emphasize the feasibility and necessity
of the implementation of thermobaricity in numerical lake models. |
| Persistent UFZ Identifier | https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=31814 |
| Marks, J., Chikita, K.A., Boehrer, B. (2025): Thermobaric circulation in a deep freshwater lake EGUsphere 10.5194/egusphere-2025-1195 |
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