Atmospheric stilling leads to prolonged thermal stratification in a large shallow polymictic lake
نویسندگان
چکیده
To quantify the effects of recent and potential future decreases in surface wind speeds on lake thermal stratification, we apply the one-dimensional process-based model MyLake to a large, shallow, polymictic lake, Võrtsjärv. The model is validated for a 3-year period and run separately for 28 years using long-term daily atmospheric forcing data from a nearby meteorological station. Model simulations show exceptionally good agreement with observed surface and bottom water temperatures during the 3-year period. Similarly, simulated surface water temperatures for 28 years show remarkably good agreement with long-term in situ water temperatures. Sensitivity analysis demonstrates that decreasing wind speeds has resulted in substantial changes in stratification dynamics since 1982, while increasing air temperatures during the same period had a negligible effect. Atmospheric stilling is a phenomenon observed globally, and in addition to recent increases in surface air temperature, needs to be considered when evaluating the influence of climate change on lake ecosystems.
منابع مشابه
Planktonic events may cause polymictic-dimictic regime shifts in temperate lakes.
Water transparency affects the thermal structure of lakes, and within certain lake depth ranges, it can determine whether a lake mixes regularly (polymictic regime) or stratifies continuously (dimictic regime) from spring through summer. Phytoplankton biomass can influence transparency but the effect of its seasonal pattern on stratification is unknown. Therefore we analysed long term field dat...
متن کاملAlpine glacier-fed turbid lakes are discontinuous cold polymictic rather than dimictic
Glacier retreat as a consequence of climate change influences freshwater ecosystems in manifold ways, yet the physical and chemical bases of these effects are poorly studied. Here, we characterize how water temperature differs between alpine lakes with and without direct glacier influence on seasonal and diurnal timescales. Using high temporal resolution monitoring of temperature in 4 lakes loc...
متن کاملComparison of Basic Limnological Aspects of Some Crater Lakes in the Cordillera Volcánica Central, Costa Rica Comparación De Aspectos Limnológicos Básicos De Algunos Lagos Cratéricos En La Cordillera Volcánica Central, Costa Rica
Crater lakes share some morphological characteristics such as size, shape, situation inside a crater, usually high elevation, which have a definite impact on their limnology. In Costa Rica there are several crater lakes that may serve as an example of small tropical lakes to examine some relationships between morphometry and stratification. The results of different limnological expeditions to f...
متن کاملDriving forces of the diel distribution of phytoplankton functional groups in a shallow tropical lake (Lake Monte Alegre, Southeast Brazil).
Phytoplankton vertical and diel dynamics in a small shallow lake (Lake Monte Alegre, Ribeirão Preto, state of São Paulo) were investigated in two climatological periods: July 2001 (cool-dry season) and March 2002 (warm-rainy season). Monte Alegre is a eutrophic reservoir, with a warm polymictic discontinuous circulation pattern. The lake was thermally stratified in both periods, although dissol...
متن کاملTransparency, Geomorphology and Mixing Regime Explain Variability in Trends in Lake Temperature and Stratification Across Northeastern North America (1975-2014)
Lake surface water temperatures are warming worldwide, raising concerns about the future integrity of valuable lake ecosystem services. In contrast to surface water temperatures, we know far less about what is happening to water temperature beneath the surface, where most organisms live. Moreover, we know little about which characteristics make lakes more or less sensitive to climate change and...
متن کامل