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Under-ice circulation, modified by the Earth's rotation, in an arctic lake
conference contribution
posted on 2023-05-23, 09:16 authored by Graves, KE, Laval, BE, Alexander Forrest, Kirillin, GRecent field observations and numerical modelling challenge the commonly held view that fluid motion under lake-ice is insignificant. This growing body of evidence indicates that under-ice circulation is an important mechanism for lateral and vertical transport of heat and pollutants in ice-covered lakes. Using direct measurements of temperature, conductivity and water column velocities in an ice-covered arctic lake, further field observations of circulation on a basin-wide scale over the entire lake depth are presented. These observations were made during a 2013 field research campaign in Lake Kilpisjarvi, Finland (approximately 69degree N, 21degree E). During the field observation period the entire water column was colder than the temperature of maximum density. Orthogonal density profiles of temperature show an approximately 500m wide upwelled density anomaly beneath the ice-cover. This anomaly consisted of warm, upwelled bottom water. Repeated temperature profiles, collected over a two-day period, show that the density anomaly persisted for the observation period of three days. Acoustic Doppler Current Profiler measurements of water column velocity show anti-cyclonic circulation around the density anomaly. The observed density profile and velocity measurements are shown to be consistent with a cyclogeostrophic force balance. These measurements show basin-wide circulation beneath ice-cover. These results contribute to the knowledge of winter hydrodynamics in lakes and the growing body of observation of lateral and vertical transport under-ice
Funding
International Network for Terrestrial Research and Monitoring in the Arctic
History
Publication title
Proceedings of the 22nd IAHR International Symposium on ICEEditors
A. W. K. LawPagination
460-466ISBN
978-981-09-0750-1Department/School
Australian Maritime CollegePublisher
International Association of Hydro-Environment Engineering and ResearchPlace of publication
SingaporeEvent title
22nd IAHR International Symposium on ICE 2014Event Venue
SingaporeDate of Event (Start Date)
2014-08-11Date of Event (End Date)
2014-08-15Rights statement
Copyright 2014 IAHR-ICE Organisers.Repository Status
- Restricted