The evolution of flow structures and energy exchange in forced rotating stratified turbulence*

We investigate the long-time evolution of the rotating stratified turbulence, concerning the flow structures and the exchange between kinetic and potential energy e_KtoP. Numerical simulations of forced three-dimensional homogeneous rotating stratified turbulence are performed at a high hyperviscous Reynolds number and low Rossby number for a sequence of Froude numbers. In the presence of stratification, with two box scale structures with opposite signs of vertical vorticity formed at later times, there are short and small vortices spreading over the flow field. Compared with anticyclonic vortices, cyclonic vortices are lack in number, easier to grow up or merge, and form the box-scale structure earlier. Moreover, the intense area of e_KtoP is associated with the cyclonic structures. We also find a relation between vertical vorticity and the distribution of the density during the evolution of turbulence, which is serviceable for modeling density by velocity.