Seeing the Invisible Present and Place: From Years to Centuries with Lake Ice from Wisconsin to the Northern Hemisphere

Long-term ice phenology records spanning up to 578 years for 78 lakes around the Northern Hemisphere

“…In 1996, a network of lake ice researchers and their data from around the Northern Hemisphere was formed, called the Lake Ice Analysis Group (LIAG) led by John Magnuson from the University of Wisconsin-Madison 5,6 . The purpose of LIAG was to form a network of researchers so that they could discover patterns not visible in short time series as well as uncover similarities and differences at broader spatial scales than previously analyzed, such as a lake, province, state, or country.…”

“…The purpose of LIAG was to form a network of researchers so that they could discover patterns not visible in short time series as well as uncover similarities and differences at broader spatial scales than previously analyzed, such as a lake, province, state, or country. They used the ideas of "Invisible present" 7 and the "Invisible place" 8 to make clear the importance of expanding the time and the space scales of ecological research to understand the world around us 6 . The first LIAG group from North America, Europe, and Asia met at the Center for Limnology's Trout Lake Station in Wisconsin, United States, to share the data amongst the group and more generally at the U.S. National Oceanic and Atmospheric Agency's National Snow and Ice Data Center.…”

“…The next major effort to update the data and expand the number of lakes was led by John Magnuson and Barbara Benson 9 . A new and expanded lake ice network with some old members and many new contributors has since been developed and led by Sapna Sharma 10,11 to update and extend the lake ice seasonality data set; the present paper is part of that effort 6 . The ice seasonality data continue to be archived at the National Snow and Ice Data Center.…”

Lake Ice From Historical Records to Contemporary Science

“…In 1996, there was a breakthrough in how long-term ecological time series could be aggregated for regions around the world. John Magnuson invited ice researchers from around the world to a workshop in Wisconsin where participants brought long-term ice phenology records from their respective countries (Magnuson, 2021). This data aggregation led to the publication of a seminal research paper, where Magnuson et al (2000) calculated trends for 37 lakes and rivers with ice-on and ice-off dates covering a 150 year period .…”

“…Long‐term in situ lake ice records have been instrumental in learning about climate change and variability (Benson et al., 2012; Magnuson et al., 2000; Newton & Mullan, 2021; Sharma et al., 2021). Because of the strong influence of climatic and weather conditions on lake ice dynamics, lake ice is considered a sentinel of climate change (Adrian et al., 2009) and has been included in the Global Climate Observing System (GCOS) as an Essential Climate Variable (ECV; (Zemp et al., 2021), in the Intergovernmental Panel on Climate Change (IPCC) review documents (Magnuson, 2021), and as a clear indicator of climate change by the United States Environmental Protection Agency (Jay et al., 2023).…”