ON THE RELATION BETWEEN OZONE STORAGE IN THE RESIDUAL LAYER AND DAILYVARIATION IN NEAR-SURFACE OZONE CONCENTRATION - A CASE-STUDY

Numerous tethered balloon soundings which measured meteorological para meters and ozone concentration during the POLLUMET field experiments a re investigated. They give indications of the influence of ozone conse rvation in the nocturnal residual layer (RL) on the development of the near surface ozone concentration of the next day. Mixing down from th e RL to the surface is simulated by a simple model based on transilien t turbulence theory, using measured profiles as initial values or mode l verification. The cases investigated show that the ozone mixed down from the RL contributes 50-70% to the maximum concentration near the s urface on the following day, the rest coming from chemical production and possibly advection. Various features of exchange characteristics b etween the RL and the nocturnal boundary layer, (NBL) are described by the analysis of the soundings. It can be shown that the vertical exch ange situation during the night can have a considerable influence on t he ozone concentration of the following day.