AIRCRAFT MEASUREMENT OF POLLUTANT FLUXES ACROSS THE BORDERS OF EASTERN GERMANY

We performed a research flight along the western and eastern border of eastern Germany to estimate the transboundary flux of pollution gases during a synoptic weather situation with westerly to southwesterly wi nds. A dolphin flight pattern was applied to sample the boundary layer as representatively as possible while screening the vertical structur e of the lower troposphere. Transboundary flux intensities were calcul ated using concentrations and wind vectors as measured by the aircraft . A detailed error analysis was performed to estimate two types of unc ertainties in the transboundary flux measurement. The error originatin g from inaccuracies in meterological and chemical measurements was est imated to be in the range 15-35% (one standard deviation). The error o riginating from the unrepresentativeness of the data collected on the flight path is estimated to be smaller by factors between 2 and 3. Tra nsboundary fluxes at the eastern side of eastern Germany were differen t from those at the western side at a high level of confidence (> 95%) . Transboundary fluxes were greater on the eastern side by a factor of 12 for SO2 and by a factor of 2.9 for NO(y). For SO2, the transbounda ry fluxes in the Ekman layer (EL) and inversion layer (IL) were greate r than those of lower free troposphere (LFT) on both sides, whereas fo r NO(y) and O3 higher LFT wind speeds compensated higher EL and IL mix ing ratios. A compilation of all available data on pollutant gas expor t from eastern Germany reveals a very heterogeneous data set. Computed average fluxes, however, show good agreement with estimates of pollut ant gas emissions from eastern Germany, based on energy consumption.