| Autor: |
Kleeorin N; Department of Mechanical Engineering, Ben-Gurion University of the Negev, P. O. B. 653, Beer-Sheva 8410530, Israel.; Nordita, Stockholm University and KTH Royal Institute of Technology, 10691 Stockholm, Sweden.; Institute for Atmospheric and Earth System Research, University of Helsinki, 00014 Helsinki, Finland., Rogachevskii I; Department of Mechanical Engineering, Ben-Gurion University of the Negev, P. O. B. 653, Beer-Sheva 8410530, Israel.; Nordita, Stockholm University and KTH Royal Institute of Technology, 10691 Stockholm, Sweden.; Institute for Atmospheric and Earth System Research, University of Helsinki, 00014 Helsinki, Finland., Soustova IA; Institute of Applied Physics of the Russian Academy of Sciences, 603950 Nizhny Novgorod, Russia., Troitskaya YI; Institute of Applied Physics of the Russian Academy of Sciences, 603950 Nizhny Novgorod, Russia., Ermakova OS; Institute of Applied Physics of the Russian Academy of Sciences, 603950 Nizhny Novgorod, Russia., Zilitinkevich S; Institute for Atmospheric and Earth System Research, University of Helsinki, 00014 Helsinki, Finland.; Finnish Meteorological Institute, 00101 Helsinki, Finland.; Faculty of Geography, Moscow State University, 119234 Moscow, Russia.; Tyumen State University, 625003 Tyumen, Russia. |
| Abstrakt: |
We have advanced the energy and flux budget turbulence closure theory that takes into account a two-way coupling between internal gravity waves (IGWs) and the shear-free stably stratified turbulence. This theory is based on the budget equation for the total (kinetic plus potential) energy of IGWs, the budget equations for the kinetic and potential energies of fluid turbulence, and turbulent fluxes of potential temperature for waves and fluid flow. The waves emitted at a certain level propagate upward, and the losses of wave energy cause the production of turbulence energy. We demonstrate that due to the nonlinear effects more intensive waves produce more strong turbulence, and this, in turn, results in strong damping of IGWs. As a result, the penetration length of more intensive waves is shorter than that of less intensive IGWs. The anisotropy of the turbulence produced by less intensive IGWs is stronger than that caused by more intensive waves. The low-amplitude IGWs produce turbulence consisting up to 90% of turbulent potential energy. This resembles the properties of the observed high-altitude tropospheric strongly anisotropic (nearly two-dimensional) turbulence. |
