On the universality of large-scale turbulence

Large-scale three-dimensional turbulence is a challenge to researchers, being one of the most complicated aspects of turbulence studies. The universal large scales behavior connected with the inverse energy cascade in two-dimensional turbulence has been known for about 35 years and studied experimentally and numerically. We have revealed the universality of three-dimensional large-scale turbulence properties experimentally and described it theoretically. A rigorous solution of this problem in the presence of an energy source gives scaling exponents -4/3 for velocity correlations and 1/3 for energy spectra of the large-scale turbulence. Such spectra are also observed in atmospheric air flows under different conditions-stable, convective, in cirrus clouds. The revealed physical phenomenon is important for the development of turbulence theory complementing the results obtained for its smaller scales. (C) 2004 American Institute of Physics.