Nutrient Input Through Occult and Wet Deposition i

Authors: E Beiderwieden A Schmidt YJ Hsia SC Chang T Wrzesinsky O Klemm

Publish Date: 2007/09/06

Volume: 186, Issue: 1-4, Pages: 273-288

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Abstract

Chemical composition of fog and rain water was studied during a 47day experimental period The differences between the fog and rain water were found to be significantly for most analyzed ions H+ NH4 + NO3 − and SO4 2− made up 85 of the total median ion concentration in fog and 84 in rain water The total mean equivalent concentration was 15 times higher in the fog than in the rain water The fog water samples were classified according to their air mass history The analysis of the 120 h backward trajectory led to the identification of three advection regimes Significant differences of ion concentrations between the respective classes were found Air masses of class I travelled exclusively over the Pacific Ocean class II were carried over the Philippines and class III were advected from mainland China The turbulent fog water deposition was determined by the means of the eddy covariance method The total turbulent plus gravitational fog water fluxes ranged between +317 mg m−2 s−1 and −566 mg m−2 s−1 Fog water droplets with mean diameters between 15 μm and 25 μm contributed most to the liquid water flux The sample based nutrient input was calculated on the basis of the occult and wet deposition and the concentrations of the simultaneously collected fog and rainwater samples respectively The nutrient input through wet deposition was about 13 times higher than through occult depositionThis study was supported by the Deutsche Forschungsgemeinschaft DFG Kl623/6 We thank A Held N Hölzel and D Lai for their help in the field and during data analysis Languageediting by M Zanetti is gratefully acknowledged The authors gratefully acknowledge the NOAA Air Resources Laboratory ARL for the provision of the HYSPLIT transport and dispersion model and READY website http//wwwarlnoaagov/readyhtml used in this publication

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