Reply to comments on “Simulating ozone dry deposition at a boreal forest with a multi-layer canopy deposition model”

A multi-layer ozone (O3) dry deposition model has been implemented into SOSAA (a model to Simulate the concen-trations of Organic vapours, Sulphuric Acid and Aerosols) to improve the representation of O3 concentration and flux withinand above the forest canopy in the planetary boundary layer. We aim to predict the O3 uptake by a boreal forest canopy undervarying environmental conditions and analyse the influence of different factors on total O3 uptake by the canopy as well as thevertical distribution of deposition sinks inside the canopy. We evaluated tThe newly implemented canopydry deposition model5was validated by an extensive comparison of simulated and observed O3 turbulent fluxes and concentration profiles within andabove the boreal forest canopy at SMEAR II (the Station to Measure Ecosystem-Atmosphere Relation II) in Hyytiälä, Finland,in August, 2010.The first half of August showed extremely warm and dry conditions which were probably representative for summerconditions prevailing at this site in future. The simulated O3 turbulent fluxes at the canopy top and the O3 concentration10profiles inside the canopy agreed well with the measurement, which indicated that the turbulent transport and the O3 drydeposition onto the canopy and soil surface appeared to be properly represented in the model.In this model, the fraction of wet surface on vegetation leaves was parameterised according to the ambient relative humidity(RH). Model results showed that when RH was larger than 70% the O3 uptake onto wet skin contributed 48.6∼ 51% to thetotal deposition during nighttime and 22.0∼ 19% during daytime. In addition, most of the O3 deposition occurred below 0.815hc (canopy height) at this site. The contribution of sub-canopy deposition below 4.2 m was modelled to be about 40% of thetotal O3 deposition during daytime which was similar to previous studies. Whereas for nighttime, the simulated sub-canopydeposition contributed 40–65% to the total O3 deposition which was about two times as that in previous studies (25–30%). Theoverall contribution of soil uptake was estimated as 36.5%. These results indicated the importance of non-stomatal O3 uptakeprocesses, especially the uptake on wet skin and soil surface.20Furthermore, a qualitative evaluation of the chemical removal time scales indicated that the chemical removal rate withincanopy was about 5% of the total deposition flux at daytime and 16% at nighttime under current knowledge of air chemistry.