SOSA – a new model to simulate the concentrations of organic vapours and sulphuric acid inside the ABL – Part 1: Model description and initial evaluation

Chemistry in the atmospheric boundary layer (ABL) is controlled by complex processes of surface fluxes, flow, turbulent transport, and chemical reactions. We present a new model SOSA (model to simulate the concentration of organic vapours and sulphuric acid) and attempt to recon- struct the emissions, transport and chemistry in the ABL in and above a vegetation canopy using tower measure- ments from the SMEAR II at Hyyti¨¨ a, Finland and avail- able soundings data from neighbouring meteorological sta- tions. Using the sounding data for upper boundary condition and nudging the model to tower measurements in the sur- face layer we were able to get a reasonable description of turbulence and other quantities through the ABL. As a first application of the model, we present vertical profiles of or- ganic compounds and discuss their relation to newly formed particles.