Received: 27 Apr 2022 – Discussion started: 03 Jun 2022
Abstract. Climate change modifies the thermal regime and the oxygen solubility of lakes globally, resulting in the alteration of ecosystem processes, lake habitats and concentrations of key parameters. The use of one-dimensional (1D) lake model for global scale studies has become the standard in lake research to evaluate the effects of climate change. However, such approach requires global scale forcing parameters which have several limitations that are barely discussed, such as the need of serious downscaling. Furthermore, projections of lakes' thermal regime are hardly ever confronted with long-term observations that extent for more than a few decades. These shortfalls limit the robustness of hindcast/ forecast simulations on decadal to centennial timescales. In this study, several 1D lake models' robustness was tested for long-term variations based on 63 years of limnological data collected by the French Observatory of LAkes (OLA). Here we evaluate the possibility to force mechanistic models by following the long-term evolution of shortwave radiation and air temperature while providing realistic seasonal trend for the other parameters for which local scale downscaling often lacks accuracy. Then, the effects of climate change on the thermal regime and oxygen solubility were analyzed in the four-largest French peri-Alpine lakes. Our results show that 1D lake models forced by air temperatures and short-wave radiations accurately predict variations in lake thermal regime over the last four to six decades, with RMSE <1.95 °C. During the last three decades, water temperatures have increased by 0.46 °C decade–1 (±0.02 °C) in the epilimnion and 0.33 °C decade–1 (±0.06 °C) in the hypolimnion. Concomitantly and due to thermal change, O2 solubility has decreased by -0.104 mg L–1 decade–1 (±0.005 mg L–1) and -0.096 mg L–1 decade–1 (±0.011 mg L–1) in the epilimnion and hypolimnion, respectively. Based on the ssp370 socio-economic pathway of the IPCC, perialpine lakes could face an increase of 3.80 °C (±0.20 °C) in the next 70 years, accompanied by a decline of 1.0 mg L–1 (±0.1 mg L–1) of O2 solubility. These results suggest important degradation in lake thermal and oxygen conditions and a loss of habitats for endemic species.
Simulated daily water temperature time series data (full water profile) for lakes Geneva, Annecy, Bourget and Aiguebelette over the period 1850-2100, based on IPCC ssp126, ssp370 and ssp585 scenariosDesgue, Olivia; Melo Vieira Soares, Laura; Anneville, Orlane; Bouffard, Damien; Chanudet, Vincent; Danis, Pierre-Alain; Domaizon, Isabelle; Guillard, Jean; Mazure, Théo; Sharaf, Najwa; Soulignac, Frédéric; Tran-Khac, Viet; Vinçon Leite, Brigitte; Jenny, Jean-Philippe https://doi.org/10.57745/PA13OK
Olivia Desgué-Itier et al.
Viewed
Total article views: 218 (including HTML, PDF, and XML)
HTML
PDF
XML
Total
Supplement
BibTeX
EndNote
164
49
5
218
15
3
2
HTML: 164
PDF: 49
XML: 5
Total: 218
Supplement: 15
BibTeX: 3
EndNote: 2
Views and downloads (calculated since 03 Jun 2022)
Cumulative views and downloads
(calculated since 03 Jun 2022)
Viewed (geographical distribution)
Total article views: 212 (including HTML, PDF, and XML)
Thereof 212 with geography defined
and 0 with unknown origin.
The long-term effects of climate change will include an increase in lake surface and deep water temperatures. Incorporating up to six decades of limnological monitoring into an improved 1D lake model approach allows us to predict thermal regime and oxygen solubility in four perialpine lakes over the period 1850–2100. Our modeling approach includes a revised selection of forcing variables and provides a way to investigate the impacts of climate variations on lakes for centennial timescales.
The long-term effects of climate change will include an increase in lake surface and deep water...