Hypolimnion

Lakes are stratified into three separate sections:
I. The Epilimnion
II. The Metalimnion
III. The Hypolimnion
The scales are used to associate each section of the stratification to their corresponding depths and temperatures. The arrow is used to show the movement of wind over the surface of the water which initiates the turnover in the epilimnion and the hypolimnion.

The hypolimnion or under lake is the dense, bottom layer of water in a thermally-stratified lake.[1] The word "hypolimnion" is derived from Ancient Greek: λιμνίον, romanizedlimníon, lit.'lake'.[2] It is the layer that lies below the thermocline.

Typically the hypolimnion is the coldest layer of a lake in summer, and the warmest layer during winter.[1] In deep, temperate lakes, the bottom-most waters of the hypolimnion are typically close to 4 °C throughout the year. The hypolimnion may be much warmer in lakes at warmer latitudes. Being at depth, it is isolated from surface wind-mixing during summer,[3] and usually receives insufficient irradiance (light) for photosynthesis to occur.

  1. ^ a b Dodds, Walter K. (Walter Kennedy), 1958- (2010). Freshwater ecology : concepts and environmental applications of limnology. Whiles, Matt R. (2nd ed.). Burlington, MA: Academic Press. ISBN 978-0-12-374724-2. OCLC 784140625.{{cite book}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  2. ^ Sadchikov, A. P.; Ostroumov, S. A. (October 2019). "Epilimnion, Metalimnion, and Hypolimnion of a Mesotrophic Aquatic Ecosystem: Functional Role of the Vertical Structure of the Reservoir Ecosystem in Terms of Hydrochemical and Biological Parameters". Russian Journal of General Chemistry. 89 (13): 2860–2864. doi:10.1134/S107036321913019X. ISSN 1070-3632. S2CID 211138964.
  3. ^ Weinke, Anthony D.; Biddanda, Bopaiah A. (2019-12-01). "Influence of episodic wind events on thermal stratification and bottom water hypoxia in a Great Lakes estuary". Journal of Great Lakes Research. 45 (6): 1103–1112. Bibcode:2019JGLR...45.1103W. doi:10.1016/j.jglr.2019.09.025. ISSN 0380-1330. S2CID 209571196.