Unveiling Energy Conversions of the Venus Atmosphere by the Bred Vectors

Abstract

The Lorenz energy cycle was often used to analyze energy conversions related to instabilities in planetary atmospheres using zonal means as basic states. Alternatively, the bred vector (BV) energy equations use the control run as basic states and detect longitudinal dependency of the energy conversions. Additionally, it quantifies contributions from baroclinic and barotropic instabilities separately. We apply this method to understand energy conversions of the Venus atmosphere. BVs are obtained from breeding cycles emphasizing perturbation growths in the cloud layer. The BV potential energy in the pressure coordinate is newly derived. Energy conversions at different latitudes in the cloud layer are examined. Results show that baroclinic conversions are stronger at higher latitudes and exceed barotropic conversions at mid- to high-latitudes. Thermal tides increase energy conversions in the morning hemisphere at mid-latitudes. This study offers new insights into energy conversions of the Venus atmosphere, with potential applications to other planetary atmospheres.