One of the most important physical characteristics driving lifecycle events in lakes is stratification. Already subtle variations in the timing of stratification onset and break-up (phenology) are known to have major ecological effects, mainly by determining the availability of light, nutrients, carbon and oxygen to organisms. Despite its ecological importance, historic and future global changes in stratification phenology are unknown. Here, we used a lake-climate model ensemble and long-term observational data, to investigate changes in lake stratification phenology across the Northern Hemisphere from 1901 to 2099. Under the high-greenhouse-gas-emission scenario, stratification will begin 22.0 ± 7.0 days earlier and end 11.3 ± 4.7 days later by the end of this century. It is very likely that this 33.3 ± 11.7 day prolongation in stratification will accelerate lake deoxygenation with subsequent effects on nutrient mineralization and phosphorus release from lake sediments. Further misalignment of lifecycle events, with possible irreversible changes for lake ecosystems, is also likely.
Bibliographical noteFunding Information:
R.I.W. received funding from the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement number 791812. T. N.M. was supported under the Climate JPI and Irish EPA project WateXr 2017-CCRP-MS.45. S.L.F. was funded by the Irish HEA Landscape programme and DkIT Research Office. J.M. and M.G. were funded from the European Union’s Horizon 2020 research and innovation programme under Marie Skłodowska-Curie grant agreement number 722518. E.J. received funding (Grant-Aid Agreement No. PBA/FS/16/02) from Marine Institute Marine Research Programme by the Irish Government. Z.T. is supported by the U.S. DOE’s Earth System Modeling programme through the Energy Exascale Earth System Model (E3SM) project. R.L. was supported through an NSF ABI development grant (#DBI 1759865). I.V. is a research fellow at the Research Foundation Flanders (FWOTM920). W.T. acknowledges the Uniscientia Foundation and the ETH Zurich Foundation for their support. T.S. was supported by the Deutsche For-schungsgemeinschaft (research grant no. DFG KI 853/13-1 and CDZ 1259) and the Helmholtz Centre for Environmental Research. V.S. and A.D. used HPC facilities of Lomonosov Moscow State University (supercomputer “Lomonosov-2”) and were supported by Russian Ministry of Science and Higher Education, agreement No. 075-15-2019-1621. R.M. participated through the project WATExR (JPI Climate ERA4CS, Grant 690462) and received support from Generalitat de Catalunya (2017SGR11) and the CERCA programme. D.M.-B. participated through the project WATExR (JPI Climate ERA4CS, Grant 690462) funded by MINECO-AEI. T.N.M. was funded by the WATExR project, which is part of ERA4CS, an ERA-NET initiated by JPI Climate, and funded by MINECO (ES), FORMAS (SE), BMBF (DE), EPA (IE), RCN (NO), and IFD (DK), with co-funding by the European Union (Grant number: 690462) and also by NSF grants DEB-1926050 and DBI-1933016. E.B.M. acknowledges the data collection on Blelham Tarn, Esthwaite Water, Windermere North Basin, and Windermere South Basin carried out by the Freshwater Biological Association and UK Centre for Ecology & Hydrology and currently supported by Natural Environment Research Council award number NE/ R016429/1 as part of the UK-SCaPE programme delivering National Capability. The computations, data handling and storage for GOTM simulations were enabled by resources provided by the Swedish National Infrastructure for Computing (SNIC) at Uppmax partially funded by the Swedish Research Council through grant agreement no. 2016-07213. Lake Superior data was collected with funding from NSF OCE-0825633. Water temperature data in Lake Washington have been collected with support from the Andrew Mellon Foundation, the National Science Foundation, and the University of Washington (D.E. Schindler, W.T Edmondson, A. Litt, unpublished data), currently through the School of Aquatic and Fishery Sciences. We thank the European Space Agency Climate Change Initiative Lakes project for providing the satellite data.
© 2021, The Author(s).