Changes in the timing and duration of Lake Erken Ice Cover

09 December 2021

The onset of ice at Lake Erken occurred on Dec 6th this year, which is a record in recent years, but put in the historical context not so unusual.

Visual observations of the onset and loss of Lake Erken’s ice cover began in 1940 and continues today, now with the assistance of the same camera used for SITES vegetation phenology monitoring (link to live webcams on the lake). The effects of ongoing climate change are leading to a clear trend in decreasing ice cover as shown for Lake Erken in graph a below. In fact, the last three years have had some of the shortest ice durations on record, with the winter of 2019-2020 having the shortest duration on record of only five days.

With this in mind, it is exciting that this year there appears to be an unusually early onset of ice cover, taking place already on Dec 6, 2021. When put into the historical context (as seen in graph b below) the ice cover did in fact start early, but this year’s early onset of ice is not so unusual. It is the 17th earliest ice onset (tied with 1979) of the data recorded at Erken. But how to interpret this against a clear trend of a later onset? This illustrates the concept that “Stationarity Is Dead”1 a problem the climate change researchers and water managers must now consider in their day to day work.
1Milly, P. C. D. et al. Stationarity Is Dead: Whither Water Management? Science 319, 573-574, doi:10.1126/science.1151915 (2008).