Connecting the long-term water level fluctuations in Great Lakes to large scale climate variability

Session: 53. - Great Lakes Water Level Fluctuations and Water Management

Vincent Cheng, University of Toronto Scarborough, [email protected]
Aisha Javed, University of Toronto Scarborough, [email protected]
Dong-Kyun Kim, University of Toronto Scarborough, [email protected]
Alex Neumann, University of Toronto Scarborough, [email protected]
Agnes Richards, Environment Canada, [email protected]
George Arhonditsis, University of Toronto Scarborough, [email protected]

Abstract

An understanding of historical water level fluctuations in the Laurentian Great Lakes is necessary for developing future management practices that will help mitigate the impacts of extreme water level variability on hydropower, ecosystems, water quality. To better understand mechanisms driving water level variability at all timescales, annual to multi-decadal water level variability of the Lake Huron-Michigan system of the Laurentian Great Lakes was studied using wavelet analyses. Results from the wavelet analysis showed several periodicities embedded in the annual water level time series. Decadal and inter-decadal variability of water levels were coherent with the El-Nino Southern Oscillation (ENSO) and Atlantic Multi-decadal Oscillation, respectively. Half decadal variability water level was also coherent with ENSO after the mid-1990s. The cumulative effect of all three oscillations appears to have driven the extreme water level variability in the late 1990s to early 2000s. In addition, the time series for NAO and evaporation were found to be synchronized to the decadal variability since 1980, the same time that evaporation began to significantly contribute to water level change. 

1. Keyword
water level fluctuations

2. Keyword
Great Lakes basin

3. Keyword
climates