Lake Thermal Dynamics in Early Winter

Due to difficult access to lakes at the time of freezing, their hydrodynamic regime is poorly known. In this study, we investigated the dynamics of temperature during the formation of ice cover in 78 m deep Lake Pääjärvi in southern Finland. First, after fall overturn, we were interested in how the water is re-establishing its gradients. Secondly, how the forming of ice plays a role in determining this mixing regime. At the deepest point of the lake vertical distribution of temperature remained uniform until 3 oC, after which temperature was inversely distributed and at times also stratified. As the water area mixed by wind reduced, we observed an increase in temperature and a decrease in oxygen below the depth of 50 m before the whole lake was ice covered. Sediment heat increased the overlaying water density initiating a flow along the rather steep sediment slopes. Our results help to understand large scale and dynamic translocations of water masses in early winter.

Print on demand book, New Book, In English, Fast Shipping from our UK Warehouse, Lake Thermal Dynamics in Early Winter printed by VDM Verlag Dr. Mueller e.K.