Long-Wave Energy Processes in the 1963 Sudden Stratospheric Warming

Abstract

Energy generation, transfer and conversion processes in the stratosphere and troposphere are investigated for the January 1963 sudden stratospheric warming using spectral forms of the energy equations. Vertical velocities, potential energy generation rates and the meridional circulation are obtained from the vorticity equation and the thermodynamic energy equation. The overall energy budgets agree well with previous estimates. Zonal available potential energy generation is positive in the troposphere and middle stratosphere, while eddy generation is negative at all levels. The stratospheric meridional circulation consists of two indirect cells with subsidence at mid-latitudes. In the domain of wave number, significant differences in the behavior of individual long waves are evident. The spectacular growth and subsequent decline of wave number two in the stratosphere were associated with strong baroclinic energy conversions and a flux of geopotential which was upward at all levels, suggesting a link with the topography of the hemisphere. Barotropic nonlinear kinetic energy transfer between eddy components is also shown to be significant in the energy budgets in both troposphere and stratosphere.