How do extreme climatic events impact lake ice phenology and ecosystem structure?

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The impact of climate change on water quality has been identified as one of the most important challenges facing humankind. However, the influence of extreme climatic events on lake ecosystems has been relatively unexplored, in part due to a paucity of long-term data. Lake ice phenology is a sensitive indicator of climate and has been recorded for centuries around the world because of its importance to transportation, winter recreation, and religion. We will capitalize on long-term climatic and ecological time series collected from hundreds of lakes around the Northern Hemisphere to quantify extreme events and their impacts on lake ice phenology, lake warming, water quality, and productivity. Overall, my research objectives are to predict the responses of lakes to multiple environmental stressors, including climate change at broad spatial and temporal scales. Here, more specifically, my research aims to answer three questions on the role of extreme climate events on lakes: 1) How do we quantify an extreme event in ecology?; 2) How do extreme climatic events influence the loss of lake ice and the timing of ice breakup and freeze?; and 3) How do extreme climatic events influence lake physics, chemistry, and biology? We will contact original data providers to update 520 lake ice phenology time-series from around the Northern Hemisphere. Moreover, we will acquire geomorphology, local weather, and large-scale climatic drivers for each lake using open-access global databases. These datasets will be merged into an open-access database to compare statistical definitions of extreme climatic events and to identify the local weather and large-scale climatic conditions required for an extreme warm event to be manifested in the ice phenology record. Next, we will quantify how extreme climatic events influence ecosystem structure in as many of the 520 lakes for which we can acquire ecosystem level data. We will quantify the physical (e.g., water temperature, stratification, water clarity), chemical (e.g., oxygen, nutrients), and biological (e.g., productivity, zooplankton biomass, fish production) responses to extreme climatic events. HQP will use and compare cutting-edge innovative statistical approaches to quantify complex relationships between weather, climate, lake morphology, and ecosystem structure to understand the impacts of extreme climatic events on lakes around the Northern Hemisphere. Ultimately, we will identify which lakes are vulnerable to warming and degraded water quality in response to extreme climatic events. These lakes will require vulnerability assessments and focused adaptation plans to mitigate climate change impacts on water quality in lakes around the world.