Terrain-induced effects on the ozone, temperature and water vapour daily variation in the upper part of the PBL over hilly terrain
Gygax, H. A.
- Publisher: Tellus B
(issn: 1600-0889, eissn: 0280-6509)
Measurements of the daily variation of several meteorological and chemical parameters in theplanetary boundary layer above the crest-height of a mountain-valley system of the SwissPlateau are presented. On the basis of the observations, it is concluded that processes at theearth-atmosphere boundary are contributing strongly to the ozone losses, the increase inhumidity, and the cooling rates observed during night-time at these higher levels. Surface-layereffects are coupled to the upper part of the boundary layer by transport processes, which resultfrom the orographic forcing of the mean wind field (i.e. occurrence of the phenomenon ofblocking) and the interaction of mean flow with locally-induced wind systems. Thus theobservations cannot be interpreted purely by local effects. In this part of the planetary boundarylayer, the additional influence of processes due to the complex topography on a more regionalscale is also felt. It is stressed that this coupling should be adequately represented in atmosphericpollution models of non-homogeneous terrain.DOI: 10.1111/j.1600-0889.1985.tb00074.x