Vertical Energy Transport in the Stratosphere during January-February 1973.

Energy, temperature and zonal wind during the stratospheric warming of January-February 1973 are investigated for five layers: 100-70 mb, 70-50 mb, 50-30 mb, 30-10 mb, and 10-.4 mb. Temperature and zonal wind patterns, derived from NMC and OXFORD satellite radiance data are plotted in cross section and compared with the results of synoptic studies. Upward flux of geopotential energy is traced from 100 mb up to .4 mb, with differences in the vertical used to estimate convergence in a layer. Energy for each layer is divided into kinetic and available potential parts, with each part further divided into eddy and mean components. Baroclinic conversion from eddy APE to eddy KE is also calculated. All eddy components are analyzed separately for the first three wavenumbers (n = 1, 2, 3). Temperature and zonal wind results compare well with synoptic studies, although the warming appears to propagate upwards, not downwards. A critical line developed and propagated both vertically and horizontally. The warming was preceeded by enhanced upward flux of n = 1 geopotential. The flux decayed with height, converging most strongly in the 30-10 mb layer, the layer of maximum warming. Baroclinic conversion was, in general, not as important as flux convergence. For the lowest four layers, mean APE increased until the end of the warming; mean KE decreased over the warming period; eddy energies in n = 1 peaked during the warming, but n = 2 and n = 3 did not. For the uppermost layer eddy KE in n = 2 was as important as in n = 1. Also, the mean energies increased beyond the end of the warming, unlike the layers below.