US Long-Term Ecological Research Network
Lake ice seasonality over the past 320 to 570 years


Lake and river ice seasonality (dates of ice freeze and breakup) responds sensitively to climatic change and variability. We analyzed climate-related changes using direct human observations of ice freeze dates (1443–2014) for Lake Suwa, Japan, and of ice breakup dates (1693–2013) for Torne River, Finland. We found a rich array of changes in ice seasonality of two inland waters from geographically distant regions: namely a shift towards later ice formation for Suwa and earlier spring melt for Torne, increasing frequencies of years with warm extremes, changing inter-annual variability, waning of dominant inter-decadal quasi-periodic dynamics, and stronger correlations of ice seasonality with atmospheric CO2 concentration and air temperature after the start of the Industrial Revolution. Although local factors, including human population growth, land use change, and water management influence Suwa and Torne, the general patterns of ice seasonality are similar for both systems, suggesting that global processes including climate change and variability are driving the long-term changes in ice seasonality.
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Data Citation Suggestion

Sharma, S., J. Magnuson, R. Batt, L. Winslow, J. Korhonen, and Y. Aono. 2022. Lake ice seasonality over the past 320–570 years ver 2. Environmental Data Initiative. Accessed 2022-11-30.

Data Download

Ice freeze dates for a 572-year period from 1443–2014 for Lake Suwa
321-year record of river ice breakup dates for Torne River from 1693–2013