This manuscript analyzes data from multi-model ensemble simulations using 5 chemistry-climate models, to assess the impacts of the 2022 Hunga eruption on the ozone layer, which injected unprecedented amount of water vapor and modest amounts of aerosol precursors. This is a result from an international collaboration activity, the Hunga Tonga–Hunga Ha’apai Volcano Impact Model Observation Comparison (HTHH-MOC) project, and the simulation protocol is explained by Zhu et al. (Geosci. Model Dev., https://doi.org/10.5194/gmd-18-5487-2025, 2025). 

In the manuscript, the changes in ozone, aerosols, water vapor, NO2, ClOx, BrOx, temperature, and zonal wind, with respect to the control simulations without any injection, are analyzed and discussed in detail. The interpretation of the simulation results seems to me mostly very reasonable. I think that the manuscript can be accepted for publication in Atmospheric Chemistry and Physics after considering the following few points. 

Figure 1(a) (and Figure S1(a)): Why does the GEOSCCM panel not have any dotted region? 

Lines 197-201: It is not clear whether the negative tropospheric ozone anomalies are due to the negative lower stratospheric ozone anomalies or due to reduced amount of stratosphere-to-troposphere transport. Please clarify in the text. 

Regarding the paragraph starting from Line 189: I feel that the cause-result relationship described here for temperature and zonal wind anomalies is not very clear to me. Is the following understanding of mine correct? If so, could you rewrite the text more clearly? 

The main causes for the temperature anomalies are composition changes (that affect radiative heating/cooling distribution) and meridional circulation changes probably due mainly to natural variability. The zonal wind anomalies are primarily the immediate response (on monthly time scales) to the temperature anomalies through the thermal wind relationship, as it is a very strong constraint. Of course, changes in the zonal wind distribution would influence the meridional circulation through changes in the Rossby wave propagation, and changes in the meridional circulation would change the ozone distribution and thus influence temperature through radiative process; but these two may be considered as secondary. 

(The main point here is that zonal wind anomalies could be just a reflection of the temperature anomalies through the thermal wind relationship.) 

Section 3.4. Its title is “Radiative impacts . . .”, but do the authors actually mean “Temperature impacts on ozone photochemistry”? This is because at Lines 345-347, the authors write about temperature dependence in the ozone chemistry. This might seem rather picky, but I think that the temperature anomalies here are probably due to both the radiative cooling due to increased water vapor and the changes in the meridional circulation (i.e. ascent anomalies), the latter of which is probably mainly due to natural variability. Note that ascent anomalies would result in both (1) adiabatic cooling and (2) less lower stratospheric ozone that leads to less solar heating on ozone there. If so, “Temperature impacts” rather than “Radiative impacts” would be more appropriate. 

Lines 386-387: Could you clarify the causes of the cooling anomalies? More longwave cooling due to increased water vapor is one cause, but ascent anomalies (if they exist) lead to adiabatic cooling and less ozone and less solar heating on ozone. 

Line 395: It would be nice that the authors clarify a little bit more what are the dynamical processes here. They could be meridional circulation, zonal wind, transport (in particular, of ozone). Or, radiative processes are also included in this term implicitly? 

Please find my report enclosed here as PDF file!