Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1029/2009GC002389
Title (Primary) Double-diffusive deep water circulation in an iron-meromictic lake
Author Boehrer, B.; Dietz, S.; von Rohden, C.; Kiwel, U.; Jöhnk, K.D.; Naujoks, S.; Ilmberger, J.; Lessmann, D.
Source Titel Geochemistry Geophysics Geosystems
Year 2009
Department ASAM; SEEFO
Volume 10
Issue 6
Page From Q06006
Language englisch
Abstract From a small meromictic lake, we present observations of a circulation pattern that has not been documented in the limnological literature before. While surface cooling drives a vertical circulation of the upper water layer (mixolimnion), the deeper water layer (monimolimnion) is not included because of its higher salt concentration. However, double diffusion (higher diffusivity of heat than of dissolved substances) facilitates the faster escape of heat from the monimolimnion compared to dissolved substances during cold periods. As a consequence, interfacial cooling drives a vertical circulation within the monimolimnion without breaking the stratification toward the mixolimnion. In the presented case, the geochemical setting does not permit dissolved substances to accumulate in the mixolimnion. As a consequence, the system approaches the case of two immiscible layers in thermal contact. Below the interface, a convection layer is formed that exceeds the staircase layer thickness of double diffusion when conservative salts are involved. Finally, the entire lake circulates as two separate convection layers. This has a decisive impact on the formation of gradients and the redistribution of dissolved substances in lakes.
Persistent UFZ Identifier https://www.ufz.de/index.php?en=20939&ufzPublicationIdentifier=74
Boehrer, B., Dietz, S., von Rohden, C., Kiwel, U., Jöhnk, K.D., Naujoks, S., Ilmberger, J., Lessmann, D. (2009):
Double-diffusive deep water circulation in an iron-meromictic lake
Geochem. Geophys. Geosyst. 10 (6), Q06006 10.1029/2009GC002389