| Summary: | Lakes are especially numerous in the arctic region, extending over about one quarter of the territory. For approximately nine months of the year, the waters of arctic lakes are under ice. Despite the duration of the ice-covered period, few studies have addressed the limnology (biological, chemical, and physical features) of these lakes during their ice-covered period. However, under ice circulation affects the background hydrodynamic state of lakes during the summer. We aim to look at the full year cycle lake circulation in order to quantify the effects of hydrodynamics on nutrient and gas fluxes and place the results within the context of climate change in the Arctic. In this study, we propose to carry out several goals: (1) to quantify physical controls on under ice thermal structure and circulation, mixing of snow melt waters and mixing during spring and fall (2) to quantify respiration rates in arctic lakes of differing morphology and geological substrates (3) to illustrate the linkages and feedbacks between these physical and biogeochemical processes. The proposed research will be carried out in lakes being studied by the Artic Long Term Ecological Research (LTER). The selected lakes are: Toolik Lake, Lake E1, Lake E5, Lake E6 and Lake N2. The Lakes range in size from 1 to 1500 hectares. We measured time series of water temperatures, specific conductance and dissolved oxygen at several depths from a taut-line moored chain of loggers in different seasons (summer and winter) and across multiple years.
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