Simulation of atmospheric convection over the River Yenisei: Study of large-scale vortices formation

Abstract

We report on a numerical simulation of morning transition in the atmospheric boundary layer above the river Yenisey near the city of Krasnoyarsk. The effect of meandering river promotes complex air circulation patterns leading to the formation of large-scale vertical vortex pair. The current LES results supports previous RANS simulations indicating the vortices positions at the minimum curvature points of the meander. The vortices affect the humidity distribution leading to uneven spreading of the water vapour along the river banks. The convective vortex pairs (rolls) are attracted toward the river during the morning ground heating. The vorticity which is transferred with these pairs is feeding the main vertical vortex. This feeding process is responsible for the large vortex stability.