The vulnerability of lakes to climate change along an altitudinal gradient

Studies of future 21(st) century climate warming in lakes along altitudinal gradients have been partially obscured by local atmospheric phenomena unresolved in climate models. Here we forced the physical lake model Simstrat with locally downscaled climate models under three future scenarios to investigate the impact on 29 Swiss lakes, varying in size along an altitudinal gradient. Results from the worst-case scenario project substantial change at the end of the century in duration of ice-cover at mid to high altitude (-2 to -107 days), stratification duration (winter -17 to -84 days, summer -2 to 73 days), while lower and especially mid altitude (present day mean annual air temperature from 9 degrees C to 3 degrees C) dimictic lakes risk shift to monomictic regimes (seven out of the eight lakes). Analysis further indicates that for many lakes shifts in mixing regime can be avoided by adhering to the most stringent scenario.

Automated summary

Studies on the climate warming of lakes along altitudinal gradients in the 21st century have been partly obscured by unresolved local atmospheric phenomena, however, using downscaled climate models under different future scenarios can help understand the potential impacts. Results suggest significant changes in ice-cover duration and stratification duration in lakes under the worst-case scenario, with the possibility of shift in mixing regimes in some lakes if stringent measures are not taken.