The exchange of wind-driven fog and mist between vegetation and the atmosphere

This paper presents a one-dimensional theoretical description of the exchange of water between wind-driven fog and natural vegetation for two processes, the first involving direct capture of the fog droplets and the second involving exchange by the evaporation/condensation process. It is shown that the 'direct capture' mechanism is formally similar to other atmosphere/vegetation exchange processes, being under the control of a 'surface' and an 'aerodynamic' resistance. A theoretical estimate is made of the magnitude and variation of this surface resistance for an idealized coniferous canopy, and consideration given to the relative importance of the two processes for both 'short' and 'tall' vegetation. The analysis is used to illuminate previous observations of the fog interception phenomenon, and as a basis for recommendations on future work in this field.