Abstract
Reductions in ice cover duration and earlier ice breakup are two of the most prevalent responses to climate warming in lakes in recent decades. In dimictic lakes, the subsequent periods of spring mixing and summer stratification are both likely to change in response to these phenological changes in ice cover. Here, we used a modeling approach to simulate the effect of changes in latitude on long-term trends in duration of ice cover, spring mixing, and summer stratification by “moving” a well-studied lake across a range of latitudes in North America (35.2°N to 65.7°N). We found a changepoint relationship between the timing of ice breakup vs. spring mixing duration on 09 May. When ice breakup occurred before 09 May, which routinely occurred at latitudes < 47°N, spring mixing was longer and more variable; when ice breakup occurred after 09 May at latitudes > 47°N, spring mixing averaged 1 day with low variability. In contrast, the duration of summer stratification showed a relatively slower rate of increase when ice breakup occurred before 09 May (< 47°N) compared to a 109% faster rate of increase when ice breakup was after 09 May (> 47°N). Projected earlier ice breakup can result in important nonlinear changes in the relative duration of spring mixing and summer stratification, which can lead to mixing regime shifts that influence the severity of oxygen depletion differentially across latitudes.
Original language | English |
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Pages (from-to) | S173-S183 |
Journal | Limnology and Oceanography |
Volume | 67 |
Issue number | S1 |
DOIs | |
State | Published - Feb 2022 |
Externally published | Yes |
Funding
The authors were supported by the Miami University Eminent Scholar in Ecosystem Ecology fund, by NSF DEB OPUS 1950170, and by NSF DEB LTREB 1754265 and 1754276, which also supported long‐term and high‐frequency data collection at Lake Giles. Partial support for high‐frequency sensor data and monitoring came from support from Kevin Rose's Global Water Laboratory at Rensselaer Polytechnic Institute. We thank Lacawac Sanctuary and Biological Field Station and B. R. Hargreaves for collection of and access to meteorological data. We thank E. P. Overholt, and the Global Change Limnology Research Laboratory at Miami University for their data collection and logistical support, and T. J. Fisher and J. Zhang for statistical advice. The authors were supported by the Miami University Eminent Scholar in Ecosystem Ecology fund, by NSF DEB OPUS 1950170, and by NSF DEB LTREB 1754265 and 1754276, which also supported long-term and high-frequency data collection at Lake Giles. Partial support for high-frequency sensor data and monitoring came from support from Kevin Rose's Global Water Laboratory at Rensselaer Polytechnic Institute. We thank Lacawac Sanctuary and Biological Field Station and B. R. Hargreaves for collection of and access to meteorological data. We thank E. P. Overholt, and the Global Change Limnology Research Laboratory at Miami University for their data collection and logistical support, and T. J. Fisher and J. Zhang for statistical advice.