Varied responses of inland waters to compound heatwave-drought events in the Yangtze River Basin.

Extreme heatwaves and droughts are coinciding more frequently worldwide, exerting far reaching and adverse effects on ecosystems and economic development. Nevertheless, our knowledge of compound heatwave drought events (CHDEs) and their negative impacts on inland waters remains relatively scarce. Our findings indicate that the average annual duration of heatwaves varies: 3-107 days in river segments, 4-69 days in directly connected lakes, and 2-71 days in controlled lakes in the Yangtze River Basin (YRB), China's largest basin from 1980 to 2022.

Episodic flooding causes sudden deoxygenation shocks in human-dominated rivers.

Dissolved oxygen (DO) sustains river ecosystems, but the effects of hydrological extremes remain poorly understood. While high river discharge (Q) enhances aeration, floods also deliver oxygen-consuming pollutants, making net impacts uncertain. Here, we analyze daily DO and its percent saturation (DO), and Q in 1156 Chinese rivers over three years.

Global dominance of seasonality in shaping lake-surface-extent dynamics.

Lakes are crucial for ecosystems, greenhouse gas emissions and water resources, yet their surface-extent dynamics, particularly seasonality, remain poorly understood at continental to global scales owing to limitations in satellite observations. Although previous studies have focused on long-term changes, comprehensive assessments of seasonality have been constrained by trade-offs between spatial resolution and temporal resolution in single-source satellite data. Here we show that seasonality is the dominant driver of lake-surface-extent variations globally.

Global elevation of algal bloom frequency in large lakes over the past two decades.

The recent increase in algal blooms in lakes, potentially exacerbated by climate warming, is of global concern. However, a spatially and temporally detailed characterization of algal bloom trends at a global scale has been lacking, posing challenges to definitively attribute the increase trend to warming as a primary driver. Here, we used daily MODIS satellite observations from 2003 to 2022 to analyze algal bloom trends in 1956 large freshwater lakes worldwide.

Subsurface heatwaves in lakes.

Lake heatwaves (extreme hot water events) can substantially disrupt aquatic ecosystems. Although surface heatwaves are well studied, their vertical structures within lakes remain largely unexplored. Here we analyse the characteristics of subsurface lake heatwaves (extreme hot events occurring below the surface) using a spatiotemporal modelling framework.