caa a22 4500 465762123 CHVBK 20180323111902.0 cr unu---uuuuu 170327e19901201xx s 000 0 eng 10.1007/BF00879764 doi (NATIONALLICENCE)springer-10.1007/BF00879764 Vertical exchange due to horizontal density gradients in lakes; the case of Lake Lucerne [Elektronische Daten] [David van Senden, Robert Portielje, Alex Borer, Heinz Ambühl, Dieter Imboden] Recent field investigations have shown that differential mixing causes a significant density driven exchange between the two eastern basins of Lake Lucerne, Gersauersee and Urnersee. The long term vertical mixing characteristics during the winter mixing period and the influence of the resulting exchange flow on water quality are examined through the analysis of ten years (1964 to 1974) of monthly limnological data. Vertical homogenization of the state variables (temperature, electric conductivity and density) occurred on average once every two years in Urnersee, but not once in Gersauersee where the ten year average winter mixed-layer depth extended to 120 m. In Urnersee intense mixing was evident over the whole water column for every year. In contrast intense mixing in the deeper layers of Gersauersee occurred approximately once every four years. A three layer model shows that theT/κ 20 signature of the Gersauersee intermediate water correlates best with the Urnersee deep water confirming the regular occurrence of a density driven exchange. For the lower layers the oxygen consumption rate in Urnersee was approximately twice that for Gersauersee. It appears the exchange flow can act either as a source or sink for the oxygen balance of Urnersee deep water. The larger rate in Urnersee hypolimnion might also be associated with the larger sediment input to this system. Density driven exchange resulting from differential mixing is probably an important contribution to the vertical water replenishment in many lakes. Birkhäuser Verlag, 1990 Density currents nationallicence vertical exchange nationallicence chemically induced density gradients nationallicence Lake mixing nationallicence hypolimnic mixing nationallicence van Senden David Environmental Physics, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut Portielje Robert Agricultural University, Wageningen, The Netherlands aut Borer Alex Environmental Physics, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut Ambühl Heinz Limnology/Hydrobiology, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut Imboden Dieter Environmental Physics, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut Aquatic Sciences Birkhäuser-Verlag 52/4(1990-12-01), 381-398 1015-1621 52:4<381 1990 52 27 https://doi.org/10.1007/BF00879764 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00879764 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- van Senden David Environmental Physics, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut NATIONALLICENCE 700 1- Portielje Robert Agricultural University, Wageningen, The Netherlands aut NATIONALLICENCE 700 1- Borer Alex Environmental Physics, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut NATIONALLICENCE 700 1- Ambühl Heinz Limnology/Hydrobiology, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut NATIONALLICENCE 700 1- Imboden Dieter Environmental Physics, ETH Zurich, Institute of Aquatic Sciences and Water Pollution Control, EAWAG, CH-8600, Dübendorf, Switzerland aut NATIONALLICENCE 773 0- Aquatic Sciences Birkhäuser-Verlag 52/4(1990-12-01), 381-398 1015-1621 52:4<381 1990 52 27 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer