On the predictability of quasi-geostrophic flow: the effects of beta and baroclinicity.

Abstract

The equilibrium statistics and predictability properties of one- and two-layer quasi-geostrophic flow are examined with the aid of a numerical model. The effect of beta in one-layer flow is to slow the transfer of energy into larger scales and to increase the predictability. In two-layer flow, when beta is zero, energy enters the system via baroclinic instability of the mean flow at very large scales and most energy transfer is confined to low wavenumbers. When beta is non-zero, energy enters at higher wavenumbers (in baroclinic modes mainly) before cascading preferentially to lower wavenumber zonal barotropic modes. -from Author