The authors have taken into account the reviewers comments, which were extremely to the point.

There are a number of comments related with technical, statistical and instrumental issues related with the trend results.

The issues and questions have been answered. However i would clarify a bit more the non ozone calibration issue of 1998 and the statistical results, since just looking at the figure it certainly looks like a step change for the ozone. Is there any other source showing (satellite based or neighboring measurement) this change ?


Ch 4.4.2 already states the following: “Both the aerosol composition, which determines if a mixture is rather scattering or absorbing, the aerosol amount, and the aerosol size distribution determine whether an increase in τaer will lead to either an increase or decrease in UV irradiance. At Uccle there is not sufficient information on both parameters to unambiguously characterize the influence of Aerosol Optical Depth on UV irradiance.”

And can be also stated that aerosol effects on UV in this study are based only
on AOD and not aerosol absorption properties changes.

P26, L 2-3: "These small particles would enhance the multiple scattering and reflection of UV radiation, which in turn would increase the UV radiation observed at the surface of the Earth."

I think this has to be deleted.

4.2.3
this is a very good paragraph with a summary of UV changes analyses.
It would be good for future readers to see the works by den Outer, Zerefos and Eleftheratos (cited also in other sections of the paper) which are more or less grouping such initiatives.


I suggest the publication of this interesting work after taking into account/clarifying more the above issues.