Climate Change and Teleconnections Amplify Lake Stratification With Differential Local Controls of Surface Water Warming and Deep Water Cooling

Abstract

Temperate lakes are experiencing increases in warming and stratification duration while global‐scale teleconnections potentially exacerbate effects of climate change. We examined interannual surface and deep water temperature change and stratification phenology in a long‐term, weekly data set (1985–2017) from a dimictic lake in New York State, USA. We developed a metric, called mixing action, to capture multiple facets about the stratified period. We found warming in surface waters and cooling in deep water. Surface warming was positively correlated with air temperature. Deep water cooling was positively correlated with spring mixing period length and deep water spring temperature, indicating a lag effect. Mixing action was correlated with global temperature anomaly and spring North Atlantic Oscillation index. With increasing summer stratification strength and length, dimictic lakes like Mohonk may continue shifting toward monomictic mixing regimes with increasing summer hypolimnetic anoxia and changing lake biogeochemistry, productivity, and habitat for aquatic organisms.

Six Decades of Thermal Change in a Pristine Lake Situated North of the Arctic Circle

“…Most notably, our analysis suggested that the temperature difference between surface and bottom waters has significantly increased at a rate 0.29°C decade −1 during the study period (p-value <0.1). A strengthening of summer stratification is an expected lake thermal response to climate change (Butcher et al, 2015;Kraemer et al, 2015;Oleksy & Richardson, 2021;Vinnå et al, 2021), and our results agree with these expectations.…”

Four Decades of Surface Temperature, Precipitation, and Wind Speed Trends over Lakes of Greece

“…For instance, a global scale analysis of lake surface water temperatures reported an average rate of lake surface water temperature increase of 0.31 • C decade −1 [4]. Other studies conducted at a regional or local scale have also shown a significant temperature increase with subsequent implications for the lake structure and functioning [41][42][43][44][45]. In our case, the average annual surface temperature increase was 0.43 • C decade −1 .…”

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

“…Both variables were significant drivers for trends in phytoplankton biomass across climatic gradients in Europe. Thus, since lake water column stability will likely increase with a warming climate (Oleksy and Richardson 2021), bloom‐forming cyanobacteria in particular will be further promoted given their typical dependence on buoyancy that makes them particularly well adapted to a stable water column (Steinberg and Hartmann 1988; Paerl and Paul 2012).…”