The generation of available potential energy by sensible heating in Southern Ocean cyclones

• Published in: Quarterly Journal of the Royal Meteorological Society
• Main Authors: Bullock, B. R., Johnson, D. R.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 1972
• Subjects: Southern Ocean
• Online Access: http://dx.doi.org/10.1002/qj.49709841703; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fqj.49709841703; https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1002/qj.49709841703

Abstract Estimates of the generation of available potential energy by sensible heating in the boundary layer for two extratropical cyclones in the Southern Ocean are presented. Boundary layer frictional dissipation is also estimated to contrast the relative importance of the storm's energy source by diabatic process with its sink by frictional effects. In the storm area of 2,000 km radial extent, representative average generation estimates by the sensible heating and frictional dissipation are 0.5 and 2.1 W m −2 , respectively, for the late developing stage. In the occluding stage, the generation increased to 0.9 W m −2 and the frictional dissipation increased to 6.2 W m −2 . The generation to frictional dissipation ratio of 1:3 and 1:7 for the two stages indicate that the in situ diabatic source of storm available potential energy is significant in the cyclogenetic stage but that its importance decreases as the storm decays. Because of the paucity of data in the Southern Ocean a simplified model to estimate the sensible heat flux is developed in this study. The model estimates the upward flux through the sea‐air interface for the synoptic scale from analyses of the depth of the adiabatic boundary layer, the surface pressure and the sea surface temperature.