Latent Heat Induced Energy Transformations during Cyclogenesis

Abstract

Abstract Using real-data numerical simulation experiments, latent heat induced energy transformations during the development of the wave cyclone of 20 May 1977 are investigated. During a 24 h period over 5 cm of precipitation fell despite baroclinically inactive synoptic conditions. The numerical experiments which were conducted included two 24 h fine-mesh forecasts, one with and the other without latent heating. The following conclusions resulted from kinetic energy budget calculations performed on isobaric surfaces at 100 mb increments from 900 mb to 100 mb. 1) Heating enhanced the generation of kinetic energy at all levels, slightly weakened its dissipation (to sub-grid scales) in the lower troposphere and increased this dissipation in the upper troposphere. 2) Because of the rapid increase of kinetic energy with height the latent heat's contribution to the kinetic energy balance was, in a relative sense, most significant in the lower troposphere. It is shown that while the maximum latent heating rates...