Evaporation and advection II: evaporation downwind of a boundary separating regions having different surface resistances and available energies

摘要: Using the model and methods developed in Part I of this study, it is shown that steady-state evaporation, downwind a sharp boundary separating uniform regions with constant but different surface resistances available energies, can be written as where ϕx dimensionless ‘exchange function’ decreases from unity to zero distance increases boundary. The symbols have their conventional meanings primes signify upwind values. form depends on profiles wind speed effective diffusivity, resistance temperature via parameter γrs/(s+γ). Empirical expressions for are obtained known solution atmospheric diffusion equations assuming power law forms diffusivity simple perfect vertical mixing beneath an impermeable inversion base. These may give some indication magnitude at small large distances respectively.