Geography and Morphology Affect the Ice Duration Dynamics of Northern Hemisphere Lakes Worldwide

Abstract

Climate change continues to diminish ice cover duration for Northern Hemisphere lakes. However, the differential loss of lake ice duration for various types of lakes across the globe is not well established. In this study, we used time series of ice duration data (average length = 51 years) for 220 globally distributed Northern Hemisphere lakes to determine how local climate trends, geographical location, and physical properties of lakes affect their ice cover trends. Ice duration dynamics were influenced by surface air temperature trends, lake geography, and morphology. Deeper lakes, located at lower elevations, western longitudes, and lower latitudes, experienced the greatest reductions in ice cover over their time series. These results indicate that despite widespread patterns of warming, the individual features of lakes can determine how rapidly they are losing ice cover and may prove informative for future modeling and conservation efforts. Plain Language Summary Citizen scientists and researchers alike have been visually logging the freezing and breakup dates of lake ice for hundreds of years. Studies have shown that lake ice duration (the number of days between freezing and breakup) has decreased over time due to human-induced climate change. We have used this type of data to determine how the size and geographic location of a lake influence how its ice cover length in winter has changed over time. We found that deep lakes, at lower elevations, western longitudes, and lower latitudes, are losing ice cover at relatively fast rates. Our results demonstrate that even though warming is a general pattern on our planet, these specific types of lakes are being affected disproportionately, which may help to prioritize conservation efforts to preserve freshwater biodiversity and drinking water resources.

Winter Climate and Lake Morphology Control Ice Phenology and Under‐Ice Temperature and Oxygen Regimes in Mountain Lakes

“…Ice cover is decreasing in many of the world's lakes (Sharma et al., 2019), creating an urgent need to understand drivers of ice phenology and winter ecology in a diversity of lake types (Hampton et al., 2017; Warne et al., 2020). Ice cover duration and timing affect ecosystem functions during open water seasons, such as thermal and mixing regimes (Smits et al., 2020; Woolway et al., 2020), oxygen dynamics (Flaim et al., 2020), and primary productivity (Hampton et al., 2017; Sadro et al., 2018b).…”

Climate Change is Contributing to Faster Rates of Lake Ice Loss in Lakes Around the Northern Hemisphere

“…(2000) had lost an additional week in lake ice cover in the recent 24‐year period (Woolway et al., 2020). These patterns are generally consistent across Canada, the United States, Finland, Sweden (Duguay et al., 2006; Hodgkins, 2013; Korhonen, 2006; Sharma et al., 2013; Weyhenmeyer et al., 2005), and the Northern Hemisphere (Benson et al., 2012; Magnuson et al., 2000; Sharma & Magnuson, 2014; Warne et al., 2020).…”

“…For example, with an additional 24 years of ice phenology data from the data set used in the publication by Magnuson et al (2000) and Woolway et al (2020) showed that the same lakes monitored by Magnuson et al (2000) had lost an additional week in lake ice cover in the recent 24-year period (Woolway et al, 2020). These patterns are generally consistent across Canada, the United States, Finland, Sweden (Duguay et al, 2006;Hodgkins, 2013;Korhonen, 2006;Sharma et al, 2013;Weyhenmeyer et al, 2005), and the Northern Hemisphere (Benson et al, 2012;Magnuson et al, 2000;Sharma & Magnuson, 2014;Warne et al, 2020).…”

Earlier ice breakup induces changepoint responses in duration and variability of spring mixing and summer stratification in dimictic lakes

“…Small, deep lakes and large, shallow lakes had a similar changepoint timing and credible intervals, suggesting a coherence in lakes of similar volume. In this case, both of these lake morphotypes need to heat a similar volume of water for ice breakup and to induce onset of summer stratification (Brown and Duguay 2010; Kirillin et al 2012; Warne et al 2020). Small, shallow lakes had a less precise changepoint, as they are most likely to have shorter periods of spring mixing due to limited fetch and thereby minimal wind‐driven mixing.…”

“…Continued climate warming may lead to greater variability in timing of ice breakup and total ice cover duration even at latitudes north of this 61°N changepoint due to shorter and more variable periods below the critical 0°C freezing threshold. Currently, lakes in mid‐latitude or temperate regions are more likely to experience reduced to intermittent ice cover with even modest warming rates, whereas more northern lakes will require greater warming before experiencing intermittent ice cover (Sharma et al 2019; Warne et al 2020). However, northern latitudes are experiencing amplified, rapid rates of climate warming (IPCC 2013), making them vulnerable to very rapid changes in ice cover phenology and the associated ecological consequences if future warming continues.…”