LB 9-84 - A glimpse into how ice is changing on Northern Hemisphere Lakes: the freeze-thaw phenology of one thousand USA lakes over thirty years

Background/Question/Methods:

Freshwater lakes are rapidly losing their ice cover under anthropogenic climate change. Understanding the dynamics and consequences of such ecosystem changes may provide an impetus for altering the trajectories of potential permanent ice-loss in some Northern Hemisphere lakes. Previous research shows that lakes in southern and coastal regions, in addition to larger and deeper lakes are most sensitive to losing ice at rapid rates.

Results/Conclusions:

This analysis benefits from long-term reporting by the Community Lake Ice Collaboration (CLIC) citizen science project. Local community members in five US states (New York, Wisconsin, Minnesota, Maine, and Michigan) monitored the dates of ice formation (winter freeze), and spring thaw, on 1000 lakes over thirty years, from 1989 to 2022. This data set allowed an investigation of the anomalies, trends, variability, and extremes of ice-on and ice-off dates across a broad landscape, as well as the identification of the lake morphological and climatic factors driving patterns in lake ice phenology. We also assessed a suite of future ice-loss scenarios through Shared Socioeconomic Pathways projections, and we identified the lakes that are most vulnerable to climate change, and the rapid loss of ice in this century.