Vol. 9, issue 04, article # 17

Abstract:

Basic theoretical concepts about the formation of fogs and aircraft condensation trails under the impact of mixing fluids with different thermogigrometric properties are developed and better understood. In general terms, the conditions are established which favor the condensation of water vapor (into a cloud) in the mixing zone. The cloud liquid water content (LWC) is calculated over the physically representative range of temperature and humidity parameters for the interacting fluids. Given realistic temperature and humidity differences, the mixing (entrainment) produces cloud LWCs well comparing to the value from experiments. The mixing (entrainment) is important for process of cloud formation in cyclones and depressions. Calculated LWCs are especially high in the clouds formed by mixing at high temperatures (25–35°C), and these values are comparable to those found in thick cumulonimbus clouds. Evidently, the horizontal mixing (entrainment), like vertical motions, plays an important part in cloud formation within cyclones and within tropical cyclones (typically not in the lower troposphere) in particular.