Energy input and dissipation in a temperate lake during the spring transition

Woolway, R. I. ORCID: https://orcid.org/0000-0003-0498-7968 and Simpson, J. H. (2017) Energy input and dissipation in a temperate lake during the spring transition. Ocean Dynamics, 67 (8). pp. 959-971. ISSN 1616-7341 doi: 10.1007/s10236-017-1072-1

Abstract/Summary

ADCP and temperature chain measurements have been used to estimate the rate of energy input by wind stress to the water surface in the south basin of Windermere. The energy input from the atmosphere was found to increase markedly as the lake stratified in spring. The efficiency of energy transfer (Eff), defined as the ratio of the rate of working in near-surface waters (RW) to that above the lake surface (P10), increased from ∼0.0013 in vertically homogenous conditions to ∼0.0064 in the first 40 days of the stratified regime. A maximum value of Eff∼0.01 was observed when, with increasing stratification, the first mode internal seiche period decreased to match the diurnal wind period of 24 h. The increase in energy input, following the onset of stratification was reflected in enhancement of the mean depth-varying kinetic energy without a corresponding increase in wind forcing. Parallel estimates of energy dissipation in the bottom boundary layer, based on determination of the structure function show that it accounts for ∼15% of RW in stratified conditions. The evolution of stratification in the lake conforms to a heating stirring model which indicates that mixing accounts for ∼21% of RW. Taken together, these estimates of key energetic parameters point the way to the development of full energy budgets for lakes and shallow seas.

Item Type	Article
URI	https://reading-clone.eprints-hosting.org/id/eprint/71418
Identification Number/DOI	10.1007/s10236-017-1072-1
Refereed	Yes
Divisions	Science > School of Mathematical, Physical and Computational Sciences > Department of Meteorology
Uncontrolled Keywords	Article, Lakes, Shelf seas, Mixing, Stratification, Dissipation
Publisher	Springer
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