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Below the temperature of maximum density (TMD) in freshwater lakes, heating at the lateral margins produces gravity currents along the bottom slope, akin to katabatic winds in the atmosphere and currents on continental shelves. We describe axisymmetric basin-scale circulation driven by heat flux at the shorelines in polar Lake Kilpisjärvi. A dense underflow originating near the shore converges toward the lake center, where it produces warm upwelling and return flow across the bulk of lake water column. The return flow, being subject to Coriolis force, creates a lake-wide anticyclonic gyre with velocities of 2–4 cm s-1. While warm underflows are common on ice-covered lakes, the key finding is the basin-scale anticyclonic gyre with warm upwelling in the core. This circulation mechanism provides a key to understanding transport processes in (semi) enclosed basins subject to negative buoyancy flux due to heating (or cooling at temperatures above TMD) at their lateral boundaries.

Item Type:	Refereed Article
Keywords:	Coriolis, winter limnology, gyre, ice cover
Research Division:	Earth Sciences
Research Group:	Physical geography and environmental geoscience
Research Field:	Geomorphology and earth surface processes
Objective Division:	Environmental Management
Objective Group:	Other environmental management
Objective Field:	Other environmental management not elsewhere classified
UTAS Author:	Forrest, AL (Dr Alexander Forrest)
UTAS Author:	Fischer, AM (Dr Andy Fischer)
ID Code:	101290
Year Published:	2015
Web of Science® Times Cited:	27
Deposited By:	NC Maritime Engineering and Hydrodynamics
Deposited On:	2015-06-16
Last Modified:	2017-10-30
Downloads:	162 View Download Statistics