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The radiatively driven natural convection beneath a floating plant layer
Author(s) -
Michael Coates,
John Ferris
Publication year - 1994
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.1994.39.5.1186
Subject(s) - macrophyte , intrusion , environmental science , water body , convection , absorption (acoustics) , differential (mechanical device) , thermal , sunlight , atmospheric sciences , hydrology (agriculture) , geology , meteorology , physics , oceanography , environmental engineering , optics , thermodynamics , geotechnical engineering , geochemistry
If part of a water body is shaded while an adjacent part is warmed by direct sunlight, contrasting thermal gradients develop. This differential heating generates a surface flow from the illuminated into the shaded portion of the water body. One example of this situation is macrophytes floating on the surface of a small lake. The macrophytes shade the underlying water, and if there is open water adjacent to this shaded region, then differential heating may be expected. We show that the presence of the roots of small floating plants displaces the intrusion downward but does not prevent its formation. Further, we show that relations describing the differential absorption mechanism in the absence of macrophyte roots remain valid with roots present. Using these relationships, we calculate that an intrusion generated by differential heating may contribute significantly to replacement of nutrients taken up by the macrophytes.