Extreme Weather Event Triggers Cascade Towards Extreme Turbidity in a Clear-water Lake

摘要: Climate forecasts project a global increase in extreme weather events, but information on the consequences for ecosystems is scarce. Of particular significance lakes are severe storms that can influence biogeochemical processes and biological communities by disrupting vertical thermal structure during periods of stratification. An exceptional storm passing over northern Germany July 2011 provided an opportunity to assess underlying mechanisms such events interplay between physics ecological characteristics deep, nutrient-poor lake. Wind speeds were among most record. A suite variables measured throughout event consistently indicates cascade pushed clear-water lake into exceptionally turbid state. Specifically, thermocline deepening storm-entrained cyanobacteria deep chlorophyll maximum located at about 8 m depth surface mixed layer. Released from light limitation, intense photosynthesis boosted primary production, increased algal biomass, raised pH thus induced massive calcite precipitation level never observed within three decades monitoring. As consequence, water transparency dropped 6.5 2.1 m, minimum record 40 years, euphotic zone shrank several weeks. These results show cyanobacterial blooms not only promoted climate warming, also be triggered storms. Clear-water developing appear particularly risk future, if become more or frequent.