My reviewer comments on egusphere-2023-1194 are in the attached Supplement.

General comments

The manuscript deals with an important subject; residential wood combustion RWC induced PM pollution in urban areas. Although Helsinki has relatively clean air in general, RWC can make a substantial contribution to PM2.5 concentrations in residential areas during winter months. Given the negative health impacts of long-term exposure to PM2.5 in low concentrations, the general topic is relevant.

The study builds on earlier modelling studies dealing with PM pollution from RWC in Helsinki. The earlier studies dealt mainly with annual level concentrations, while this study concentrated on validation against monitoring and temporal aspects. Therefore it shows a reasonable level of novelty.

Overall the manuscript is well and clearly written, and the results are presented in a logical manner. It presents concrete conclusions about important future research needs for temporal aspects of emission inventories. The conclusions chapter itself is longish with repetition about what has been done, and some discussion-like parts with references. Authors might want to consider moving some of these to earlier parts, or adding a Discussions chapter (if the format of the journal allows).

Specific comments

Lines 60-65:

Authors introduce reasons for increase and decrease of RWC in Europe. It is not clear whether the whole chapter is based on Viana et al. or is the vague analysis in the later part the authors’ own thinking.

The growing concern for the health impacts associated with the emissions attributed to RWC has resulted in a consideration of abatement measures for RWC.

Who has considered, and provide reference or clearly indicate if based on Viana et al.

In the long run, this might possibly result in a decreasing trend in RWC, but due to the current requirements to decrease the use of fossil energy in the EU, a significant change is not expected in the near future.

This gives an impression that the changes in the intensity of use of wood in the residential sector in the EU is mainly policy driven. Deepen the analysis and give support with references.

Lines 153-154:

It has previously been found that the contribution of other urban source categories to the PM2.5 concentrations has not been significant in this region.

Provide a reference who has found out. Often other emission sources than the ones mentioned here make a considerable contribution in urban emission inventories. For instance, construction and maintenance activities of housing and streets. To what extent e.g. construction machinery, snow clearing, motorized gardening etc. are included in the vehicular traffic category? And barbeques are mentioned later on.

Section 3.1.1:

Authors discuss factors that might affect the differences between modelled and measured concentrations. How about the uncertainties related to the spatial distribution of the emissions? How well the actual intensity of the use of RWC inside each 100m grid cell near the monitoring station is known? Although the locations of fireplaces in each house might be known from the house register, the frequency of the use might vary substantially from house to house in supplementary or recreational function. Are there any information about the variability from the surveys and has this been taken into account?

Lines 319-321:

These over-predictions at the residential sites in winter were probably caused by the assumed semi-empirical seasonal variation of RWC emissions in winter; this variation function may not have been ideal for the meteorological conditions during the considered periods.

What evidence exists that this is the case? Would it be possible to draw out data from questionnaires to support this conclusion?

Lines 454-455:

However, the recent deterioration of the economic situation and high energy prices may favour wood burning and increase emissions.

This is questionable for any mid or longer term prognosis and outdated already for the part of energy prices.

Technical corrections:

Line 431:

Repetition of clearly.