Editors review of paper acp-2019-538: by Delaria et al.

Dear authors, co-authors,

I have received now three reviews of your paper of your paper on “A model-based analysis of foliar NOx deposition” submitted for publication in ACP. In the meantime you have provided a response to the comments provided by those reviewers and also revised the ms to handle those comments. Before coming to my final decision on your paper I do though want to share with you one additional editors comment that according to me should also still be addressed. This comment is rather similar to one I provided in my role as reviewer of one of your previous papers on atmosphere-biosphere NOx exchange.

My comment is mainly raised reading the following sentence in your ms.

“Many global scale chemistry transport models (Jacob and Wofsy, 1990; Wang and Leuning, 1998; Ganzeveld et al., 2002) parameterize Vd using the resistance in-series approach similar to that developed by Wesely (1989)”

The reference to Ganzeveld et al., 2002 presented the development and evaluation of an implementation of a multi-layer canopy exchange modelling system. There we indeed discussed what was that time the common approach to represent atmosphere-biosphere exchange in large-scale chemistry-transport models. However, that study actually showed a new multi-layer approach also implemented in a chemistry-climate modelling system (ECHAM, presented in the accompanying paper on Global atmosphere-biosphere exchange of NOx and the role of canopy interactions). This multi-layer modelling system included a stomatal resistance representation considering, besides specific features such as the NO2 compensation point, also the impact of soil moisture simulated by the climate model. It didn’t though not yet consider the VPD effect, a feature that is especially addressed in your ms and other more recent studies on atmosphere-biosphere exchange of NOx and other reactive compounds. I am also bringing in this point, having seen quite some other studies more focussed on AQ topics that clearly missed some of such details already considered in chemistry-climate studies. The different research communities are not always informed about the state-of the art of research methods applied by those different communities. I think it is appreciated if your paper also properly describes to what extent such details are represented in the various models to assess atmosphere-biosphere NOx exchange.

I am aware that it would have been more optimal that I would have shared this comment also earlier so that you could have also included this straightaway in your replies/revision but think that this comment can rather easily still be handled and will then use all feedback to decide how to proceed,

Regards, Laurens Ganzeveld

Dear author, co-authors, (having again a delayed response now for other reasons only being back in the office for some days), I accept your ms on the 1-D modelling of NOx exchanges for publication in ACP. Hope that this will also further trigger the continuous discussions/efforts to ultimately revise the big-leaf representation of atmosphere-biosphere (NOx) exchange currently still being applied in basically all the large-scale modelling systems for atmospheric chemistry studies.

Regards, Laurens Ganzeveld