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

Abstract

In recent decades, lakes have experienced unprecedented ice loss with widespread ramifications for winter ecological processes. The rapid loss of ice, resurgence of winter biology, and proliferation of remote sensing technologies, presents a unique opportunity to integrate disciplines to further understand the broad spatial and temporal patterns in ice loss and its consequences. Here, we summarize ice phenology records for 78 lakes in 12 countries across North America, Europe, and Asia to permit the inclusion and harmonization of in situ ice phenology observations in future interdisciplinary studies. These ice records represent some of the longest climate observations directly collected by people. We highlight the importance of applying the same definition of ice-on and ice-off within a lake across the time-series, regardless of how the ice is observed, to broaden our understanding of ice loss across vast spatial and temporal scales.

An Introduction to the Community Lake Ice Collaboration: A Long‐Term Lake Ice Phenology Community Science Project Spanning 1000 Lakes and Over 30 Years

“…Lakes in the contiguous states of the United States of America are one of the most vulnerable regions to losing ice cover within this century (Sharma et al 2019). We currently have updated records for handfuls of lakes across Wisconsin, Minnesota, New York, New Hampshire, and Maine within the Global Lake and River Ice Phenology database housed at the National Snow and Ice Data Centre based on long-term human observations (Benson et al 2000(Benson et al , updated 2021Sharma et al 2022). However, we currently lack observations for smaller and shallow lakes across a landscape.…”

Shortening ice seasons and changing phenology affect under-ice lake thermal dynamics

“…The lake's surface area occupies 40% of the watershed in a small glacier-formed depression on the Shawangunk Ridge (Richardson et al, 2018). Ice-on day was recorded as the first day with 100% ice coverage; ice-off day was recorded as the first day with 0% ice cover from 1932-2022 (Sharma et al 2022). Ice phenology was recorded in a consistent manner over the entire 90-year data record with only seven years missing ice-on data (all earlier than the 1954 water year) and one year of missing ice-off record in the 1965 water year (Sharma et al 2022).…”

“…Ice-on day was recorded as the first day with 100% ice coverage; ice-off day was recorded as the first day with 0% ice cover from 1932-2022 (Sharma et al 2022). Ice phenology was recorded in a consistent manner over the entire 90-year data record with only seven years missing ice-on data (all earlier than the 1954 water year) and one year of missing ice-off record in the 1965 water year (Sharma et al 2022). Over the entire ice record, maximum, minimum, and average daily air temperature (°C) and snow and precipitation (mm) were measured within 50 m of the lake at a National Weather Service station (Network ID: GHCND:USC00305426).…”

“…Predicting how ongoing changes in lake ice phenology will alter annual, whole-lake ecosystem function first requires an understanding of the drivers of trends and variability around those trends (Wilkinson et al, 2020). While lake ice phenology records are common, observations of multi-decadal under-ice thermal properties are comparatively rare (e.g., Sharma et al, 2022). Under-ice temperatures are critical in contextualizing the physical, chemical, and biological implications of increasingly shorter and potentially variable ice phenology.…”

“…We analyzed a 90-year record of both ice-on and ice-off observations from a small, mountain lake in New York, USA (Sharma et al 2022). We combine the long-term ice phenology record with weekly under-ice thermal profiles from the most recent 36 years to ask the following questions.…”