METEOROLOGICAL CONDITIONS AT THE RELEASE SITE DURING THE 2 TRACER EXPERIMENTS

The state of the boundary layer at the release site during the two tra cer experiments is described, based on measurements of atmospheric tur bulence carried our by a sonic anemometer, profiles of horizontal and vertical wind by a SODAR as well as frequent radiosonde releases. The boundary layer height is derived from radiosoundings, modelled and dis cussed. The study is meant as background for discussions of the tracer behaviour near the release site, and possible influence of the local meteorology at the release site on the long-range dispersion. The diff erence in the initial mese-meteorological conditions between the two e xperiments is discussed and some of its consequences for the dispersio n of the released tracer are clarified. It is concluded that the first experiment is well suited for validation of long-range transport and dispersion models, whereas the second experiment calls for further mod el development. It is concluded that the micrometeorological measureme nts are very important as background information for the understanding of plume behaviour on small as well as long scales. (C) 1998 Elsevier Science Ltd. All rights reserved.