Unprecedented Seasonal Water Level Dynamics on One of the Earth's Largest Lakes

The North American Great Lakes contain roughly 20% of the Earth's unfrozen fresh surface water and cover a massive area. Water levels on the Great Lakes have been recorded continuously for more than 150 years, representing one of the longest sets of direct hydroclimate measurements. Further investigation will be needed to fully understand the range of factors driving the changes in the Lake Erie seasonal water cycle, and the extent to which comparable changes are taking place on the other Great Lakes. Nonetheless, the stark difference in seasonal water-level dynamics between 2011 and 2012 on Lake Erie, and the ongoing shift in the Lake Erie seasonal water level cycle, are both related to changes in the magnitude and timing of runoff, overlake precipitation, and overlake evaporation. Lake Erie water-level dynamics in 2011 and 2012 collectively represent unprecedented year-to-year variability in the seasonal water-level cycle, yet while the water-level cycle in 2011 represented an amplification of the average seasonal cycle.