Abstract

Juxtaposing Clausius-Clapeyron relation derived in 1832 with Hydrodynamic concept of atmosphere parcel of air leads to the discovery of an essential property of the troposphere that will deeply ameliorates information contained in literature and audiovisual productions on tropical weather. It is indeed a rectification of the use of an ideal gas principle which enshrined the idea that, hot air is lighter than cold air throughout the atmosphere. In other words, contrary to what has been taught in schools and universities of the world, hot air isnot lighter than cold air in all parts of the troposphere. Taking into account this tropospherethermodynamics reality improves our understanding of complex weather phenomena such as cyclones and hurricanes. The two equal level surfaces of water vapor and temperaturerating respectively at 6.11 mb and 0.0098°C separate without any ambiguity parts of the troposphere where ideal gas assumption can be applied to parts of the troposphere wherethis assumption is banned.

Key words: Clausius-Clapeyron relation, Hydrodynamic concept of air parcel, equal levelsurfaces, rating at 6.11 mb and 0.0098°C.