ISSN:
1420-9055
Keywords:
Horizontal mixing
;
Lake Constance
;
tracer experiment
;
sulfur hexafluoride
;
integrating sampler
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Horizontal mixing processes in the hypolimnion of the western part of Lake Constance are studied by measuring the dispersion of a sulfur hexafluoride (SF6) tracer plume. Only 1 liter gaseous SF6 (STP) was released at a central hypolimnic depth of 60 m in August 1990. Over a period of 3 months the horizontal dispersion of the tracer plume was measured by 19 surveys using a new, vertically integrating sampling device. The observed horizontal dispersion is marked by strong storm-induced stirring events. Nevertheless mean turbulent diffusion coefficients for the whole period can be computed. They rise about linear from 0.7 ⋅ 105 cm2/s to 3.0 ⋅ 105 cm2/s with the distance from the western end of the lake. For the hypolimnion of Überlingersee, a sill-separated basin in the western part of Lake Constance, a simple budget model gives an exchange time of 67 ± 6 days with the main basin (Obersee).
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00877179
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