A3.1 Long range transport of Nutrients

PI(s) for this project:


Long-range transport of nutrients into the mountainous rain forest of southern Ecuador


Rain and fog-water measurements along an altitude profile between 1800 and 3185 m in the ECSF area and analyses of ion composition of rain and fog-water samples show episodes of significantly enhanced nitrogen and sulphur input into this ecosystem, with annual deposition rates being comparable to those of polluted central Europe. By means of back trajectories it could be shown that biomass burning in the Amazon is the likely source of this additional nitrate, ammonia and sulphate "fertilizer". First oxygen isotope analyses of nitrate in fog-water samples confirm photochemical conversion of precursor substances emitted from fires. This project aims at quantifying the atmospheric deposition of nutrients by rain- and fogwater and the anthropogenic contribution resulting from biomass burning, atmospheric transformation and long-range transport, by applying stable isotope analyses and combining remote sensing data (NOAA, MODIS) and modelling methods (FLEXTRA trajectory-modelling). ENVISAT-data will provide atmospheric distributions of NO2, H2CO and CO. Along with back trajectories and chemical and isotopic analyses of wet and dry deposition samples these methods will enable a better understanding of the impact of the ongoing land use changes in the south American tropics and the tropical mountain forest ecosystem.