Premium
Mixing of an interflow into the ambient water of Lake Iseo
Author(s) -
Hogg Charlie A. R.,
Marti Clelia L.,
Huppert Herbert E.,
Imberger Jörg
Publication year - 2013
Publication title -
limnology and oceanography
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.7
H-Index - 197
eISSN - 1939-5590
pISSN - 0024-3590
DOI - 10.4319/lo.2013.58.2.0579
Subject(s) - interflow , froude number , mixing (physics) , buoyancy , hydrology (agriculture) , geology , inflow , mechanics , environmental science , geotechnical engineering , flow (mathematics) , physics , oceanography , groundwater , quantum mechanics
River water flowing as an interflow was investigated using field data, collected in Lake Iseo (Italy), and theory. A theory for the lateral falling mechanism of plunging was developed for inflows when the initial densimetric Froude number ( Fr 0 ) is slightly larger than unity. The ratio of the river width to the offshore extent of the plunge region was equal to Fr 0 . The mixing ratio in the plunge region was 0.06. Theoretical results were quantitatively consistent with the length scale and mixing ratio of the observed plunge region. The progression of the inflow was interpreted as: initially a laterally falling plunge region with little mixing; followed by a steep underflow region with substantial mixing; and finally an intrusion. The intrusion was at first controlled dynamically by an inertia‐buoyancy force balance. Further from the liftoff point, turbulent mixing effects dominated over those due to inertia. Ultimately, the intrusion diffused into the adjacent layers in such a way that the interflow fluid was effectively indistinguishable from the lake water.