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Related to hypolimnion: Metalimnion


 (hī′pə-lĭm′nē-ŏn′, -ən)
The layer of water in a thermally stratified lake that lies below the thermocline, is noncirculating, and remains perpetually cold.

[hypo- + Greek limnē, lake, pool.]

hy′po·lim·net′ic (-lĭm-nĕt′ĭk), hy′po·lim′ni·al adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


n, pl -nions or -nia (-nɪə)
(Physical Geography) the lower and colder layer of water in a lake
[C20: from hypo- + Greek limnion, diminutive of limnē lake]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˌhaɪ poʊˈlɪm niˌɒn, -ni ən)

n., pl. -ni•a (-ni ə)
(in certain lakes) the layer of water below the thermocline.
[1905–10; hypo- + Greek -limnion, derivative of límnē lake]
hy`po•lim•net′ic (-lɪmˈnɛt ɪk) hy`po•lim′ni•al, adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
The results for water quality parameters measured between May and October 2007 at Prairie Creek reservoir showed oxygen depletion in the hypolimnion, low water transparency, high nutrient concentrations, especially phosphorus, and increased concentrations of chlorophyll a.
Mechanical agitation: During mechanical agitation, water is pumped from the hypolimnion into a splash basin that is located on the surface of the lake or reservoir.
With the onset of stratification, [O.sub.2] in the hypolimnion is rapidly utilized in the oxidation of organic matter.
From the covariance structure the following major signals were detected to be related to higher winter temperature: a more intense spring algal maximum, a higher zooplankton biomass during the algal maximum, a less intense loss of nutrients to the hypolimnion, a higher summer bloom together with changes in the nutrient concentrations, and stronger oxygen consumption in autumn.
For any given lake DOYES = 1 if the dissolved oxygen in the lake's hypolimnion is greater than 5ppm at virtually all times.
From September 2002 to September 2003, limnological features were described from individual water samples collected from the epilimnion and hypolimnion with a Van Dorn bottle (5 L).
Turnover--In fall, the surface layer (epilimnion) cools, eventually equalling the temperature of the layer below the thermocline (the hypolimnion).
Therefore, the water temperature in the hypolimnion is higher in whitewaters lakes than that in black-water lakes.