ИСТИНА

A 1D model for enclosed basin (lake) is presented, reproducing temperature, horizontal velocities, oxygen, carbon dioxide and methane in the basin. All prognostic variables are treated in unified manner via generic 1D transport equation for horizontally averaged property. To the best of our knowledge, this is the most general form of 1D diffusion-type equation for a lake model available in the literature so far. Water body interacts with underlying sediments. These sediments are represented by a set of vertical columns with heat, moisture and methane transport inside. The model is validated vs. comprehensive observational dataset gathered at Kuivajarvi Lake (Southern Finland). Our results suggest that a gas transfer through thermocline under intense seiche motions is a bottleneck in quantifying greenhouse gas dynamics in dimictic lakes, calling for further research. We overview the seiche models existent so far in literature, from a perspective of their usage in 1D lake models for taking into account seiche-induced vertical mixing. We speculate on their capabilities and drawbacks, as well as on the new approaches for parameterizing internal seiching. We test different methods for calculating seiche mixing vs. the data of 3D hydrodynamic modelling.