2022 was an unusual year for Ice Breakup. Just as the ice was about to leave, there were a couple of days of high winds which seemed to concentrate the remaining vestiges of ice into ice packs, which were then driven into various bays. In South Bay, for instance the ice usually recedes from the shore, but this year the aforementioned icepack came back to the shore and there it lingers.
The waters immediately before the culverts are usually open all year, due to the flow of fast shallow water. This year, however, an icepack was pushed towards the culvert and lingered. In fact, on the 18th of April there were people launching docks there in the open water just south of the pack!
So, when is the ice really out?
One could decide that it is “When not enough ice can be found to adequately water my scotch”.
Another criterion could be “When the ice cover breaks up and open water becomes extensive.”
If one is looking for trends, i.e., how things change over time, the key is to be consistent in the observation and evaluation process. So, each of the above are equally valid criteria for identifying trends in “Ice-Out”, so long as they are applied as consistently as possible year over year.
The United States Environmental Protection Agency (EPA) monitors Climate Change Indicators, and one of them is Lake Ice. Their take on the subject can be found at https://www.epa.gov/climate-indicators/climate-change-indicators-lake-ice.
Quoting from their website:….
– Thaw dates occur when the ice cover breaks up and open water becomes extensive.
– Data used in this indicator are all based on visual observations. While the procedures for making observations of lake ice are consistent over time, visual observations by individuals are open to some interpretation and can differ from one individual to the next. In addition, historical observations for lakes have typically been made from a particular spot on the shore, which might not be representative of lakes as a whole or comparable to satellite-based observations. Considerations for defining the thaw date are specific to each lake.
– Thaw dates for most lakes show a trend toward earlier ice breakup in the spring. Spring thaw dates have grown earlier by up to 24 days in the past 114 years. Nearly all lakes were found to be thawing earlier in the year.
This year, using the same procedure employed by the same observer for the last 35 years, the Ice-Out date at Chandos has been determined to be April 15, and although this may be understandably unsatisfactory to some, for reasons explained above, it is what we are entering into our historical record. (Now please get me a scotch, on the rocks!)