Book contents
- Frontmatter
- Contents
- Preface
- 1 Observation of clouds
- 2 The shape and size of cloud and precipitation particles
- 3 Molecular structures of water substance
- 4 Bulk thermodynamic equilibrium among water vapor, liquid water, and ice
- 5 Surface thermodynamics of water substance
- 6 Aerosol in the atmosphere
- 7 Nucleation
- 8 Hydrodynamics of cloud and precipitation particles
- 9 Diffusion growth and evaporation of cloud and precipitation particles
- 10 Collision, coalescence, breakup, and melting
- 11 Cloud drop population dynamics in the warm rain process
- 12 Fundamental cloud dynamics
- 13 Numerical cloud models
- 14 Cloud electricity
- 15 Clouds–environment interaction
- References
- Index
- Plate section
5 - Surface thermodynamics of water substance
Published online by Cambridge University Press: 05 March 2013
- Frontmatter
- Contents
- Preface
- 1 Observation of clouds
- 2 The shape and size of cloud and precipitation particles
- 3 Molecular structures of water substance
- 4 Bulk thermodynamic equilibrium among water vapor, liquid water, and ice
- 5 Surface thermodynamics of water substance
- 6 Aerosol in the atmosphere
- 7 Nucleation
- 8 Hydrodynamics of cloud and precipitation particles
- 9 Diffusion growth and evaporation of cloud and precipitation particles
- 10 Collision, coalescence, breakup, and melting
- 11 Cloud drop population dynamics in the warm rain process
- 12 Fundamental cloud dynamics
- 13 Numerical cloud models
- 14 Cloud electricity
- 15 Clouds–environment interaction
- References
- Index
- Plate section
Summary
In the last chapter, we discussed the thermodynamic equilibrium among different phases of water substance and derived the Clausius–Clapeyron equation to describe the equilibrium quantitatively. We found that, while this equation is useful in many respects, it has problems when predicting certain phenomena related to phase change due to its omission of surface effects in the system. In actual clouds, especially in the initial stage of cloud formation, particles often have high curvatures and hence strong curvature effects, which cannot be neglected. In this chapter, we will study the surface effects and then use that knowledge to study the equilibrium behavior of cloud and precipitation particles in a more realistic way.
The interface as a phase
The interface between two bulk phases is a very special “system” that sometimes is more complicated than a bulk system. Conceptually we often simplify the interface as a geometrical surface (i.e. no thickness but has area), but in reality it must be a layer of finite thickness (albeit very, very thin). Fig. 5.1 shows a conceptual model of the interface between liquid water and water vapor for a water drop of radius a.
- Type
- Chapter
- Information
- Physics and Dynamics of Clouds and Precipitation , pp. 107 - 133Publisher: Cambridge University PressPrint publication year: 2013