Quantification of Fog Deposition with Two Similar Set-ups

The turbulent deposition of fog and cloud water is an important pathway for atmospheric inputs of pollutants to vegetation, especially to forest ecosystems. Based on a study by Trautner [1988], Wrzesinsky and Klemm [2000] estimated that fog deposition contributes 20--50% to total liquid water deposition in the Fichtelgebirge mountains in Germany. They point out that these calculations are associated with large uncertainties. One common goal of the two projects "Fog Interception and Nutrient Inputs to Montane-Subalpine Areas in Switzerland" (Institute of Geography, University of Bern, Switzerland) and "Quantification of the Input of Water and Nutrients Into a Forest Ecosystem Through the Deposition of Fog" (Bayreuth Institute for Terrestrial Ecosystem Research, University of Bayreuth, Germany) is the evaluation of a measurement set-up which allows the direct measurement of the liquid water input by fog employing the eddy covariance technique. During summer and autumn 2000 two almost identical set-ups were running simultaneously on a meteorological tower in the Fichtelgebirge mountains. First results of this intercomparison study are presented in this paper